Search

Abstract Background The emergence of Plasmodium falciparum drug resistance against artemisinin-based combination therapy has threatened malaria control efforts. Since malaria control and elimination plans are dependent on these drugs, they must remain efficacious. However, resistance to these drugs was detected in low-transmission settings and is predicted to emerge in high-transmission settings, including in unspecified areas of Ethiopia. Therefore, this study aimed to assess the therapeutic efficacy and safety of artemether-lumefantrine for the treatment of uncomplicated P. falciparum malaria. Methods A single-arm prospective observational study was conducted at Teda Health Centre, Northwest Ethiopia, by following the 2009 World Health Organization efficacy study guidelines from September 2022 to February 2023. Patients with uncomplicated falciparum malaria were conveniently selected and treated with a standard dose of artemether-lumefantrine, along with a single low dose of primaquine. Then clinical and parasitological responses and haemoglobin levels were assessed during the 28-day scheduled follow-up. Blood films were examined and asexual parasites were quantified; axillary temperature was measured; and drug adverse events were assessed throughout the follow-up. Finally, the drug efficacy (adequate clinical and parasitological response) was determined by Kaplan–Meier and per-protocol analyses. The data were analysed using the WHO Excel spreadsheet and SPSS version 25 software. Results The success rates of PCR uncorrected and corrected Kaplan–Meier analysis on day 28 were 95.8% (95% CI 87.5–98.6) and 97.3% (95% CI 89.4–99.3), respectively. The per-protocol PCR uncorrected and corrected adequate clinical and parasitological responses were 95.5% (95% CI 87.5–99.1) and 97% (95% CI 89.5–99.6), respectively. On day-3, 97% of study participants were free of asexual parasitaemia, and all of them were fever-free on day-2. All of the gametocyte-positive patients at baseline were found to be negative for gametocytes on day-2. Moreover, the baseline mean hemoglobin of 13.10 g/dl increased slightly on day-14 to 13.27 g/dl but significantly on day-28 to 13.69 g/dl in a paired sample t test. All adverse events reported were mild. Conclusion Artemether-lumefantrine continued to be an efficacious and safe drug for the treatment of uncomplicated Plasmodium falciparum malaria at the Teda Health Centre. Trial registration: unique ID# PACTR202309773069812 at https://pactr.samrc.ac.za on September 1, 2023.

Abstract Background The burden of malaria persists in sub-Saharan Africa and the emergence of artemisinin resistance has introduced complexity to control efforts. Monitoring the efficacy of artemisinin-based treatment for malaria is crucial to address this challenge. This study assessed treatment efficacy of artemether-lumefantrine (AL) and genetic diversity of Plasmodium falciparum isolates in a Nigerian population. Methods Participants presenting with clinical symptoms of uncomplicated malaria at a health centre in Lagos, Nigeria, were screened for P. falciparum. Enrolled participants were treated with AL and monitored through scheduled check-up visits, clinical and laboratory examinations for 28 days. Parasite clearance and genetic diversity were assessed through polymerase chain reaction (PCR) analysis of merozoite surface proteins (msp1 and msp2). The prevalence of drug resistance mutations was assessed by P. falciparum multidrug resistance gene 1 (mdr1) genotyping followed by P. falciparum ubiquitin-specific protease 1 (ubp1) gene sequencing. Results The PCR-uncorrected treatment outcome revealed 94.4% adequate clinical and parasitological response (ACPR) and 5.6% late parasitological failure (LPF) rates. After PCR correction, no suspected LPF case was detected and ACPR 67/67 (100%) was achieved in all the individuals. Moreover, a high prevalence of wild-type alleles for mdr1 N86Y (93.7%), and mdr1 D1246Y (87.5%) was observed. Genetic diversity analysis revealed predominant K1 allelic family for msp1 (90.2%) and FC27 for msp2 (64.4%). Estimated multiplicity of infection (MOI) was 1.7, with the highest MOI observed in the 5–15 years age group. ubp1 sequence analysis identified one nonsynonymous E1528D polymorphism at a low frequency (1.6%). Conclusion The study demonstrated sustained efficacy of AL for treating uncomplicated P. falciparum malaria. Genetic diversity analysis revealed various allelic types, suggesting occurrences of polyclonal infections. Nonetheless, the detection of a significant ubp1 polymorphism could have future implications for the epidemiology of anti-malarial drug resistance in the population.

Abstract Background Malaria remains a major global health problem although there was a remarkable achievement between 2000 and 2015. Malaria drug resistance, along with several other factors, presents a significant challenge to malaria control and elimination efforts. Numerous countries in sub-Saharan Africa have documented the presence of confirmed or potential markers of partial resistance against artemisinin, the drug of choice for the treatment of uncomplicated Plasmodium falciparum malaria. The World Health Organization (WHO) recommends regular surveillance of artemisinin therapeutic efficacy to inform policy decisions. Methods This study aimed to evaluate the therapeutic efficacy of artemether-lumefantrine (AL), which is the first-line treatment for uncomplicated P. falciparum malaria in Ethiopia since 2004. Using a single-arm prospective evaluation design, the study assessed the clinical and parasitological responses of patients with uncomplicated P. falciparum malaria in Metehara Health Centre, central-east Ethiopia. Out of 2332 malaria suspects (1187 males, 1145 females) screened, 80 (50 males, 30 females) were enrolled, followed up for 28 days, and 73 (44 males, 29 females) completed the follow up. The study was conducted and data was analysed by employing the per-protocol and Kaplan–Meier analyses following the WHO Malaria Therapeutic Efficacy Evaluation Guidelines 2009. Results The results indicated rapid parasite clearance and resolution of clinical symptoms, with all patients achieving complete recovery from asexual parasitaemia and fever by day (D) 3. The prevalence of gametocytes decreased from 6.3% on D0 to 2.5% on D2, D3, D7, and ultimately achieving complete clearance afterward. Conclusion The overall cure rate for AL treatment was 100%, demonstrating its high efficacy in effectively eliminating malaria parasites in patients. No serious adverse events related to AL treatment were reported during the study, suggesting its safety and tolerability among the participants. These findings confirm that AL remains a highly efficacious treatment for uncomplicated P. falciparum malaria in the study site after 20 years of its introduction in Ethiopia.

Background: The emergence of Plasmodium falciparum drug resistance against artemisinin-based combination therapy has threatened malaria control efforts. Since malaria control and elimination plans are dependent on these drugs, they must remain efficacious. However, resistance to these drugs was detected in low-transmission settings and is predicted to emerge in high-transmission settings, including in unspecified areas of Ethiopia. Therefore, this study aimed to assess the therapeutic efficacy and safety of artemether-lumefantrine for the treatment of uncomplicated P. falciparum malaria. Methods: A single-arm prospective observational study was conducted at Teda Health Centre, Northwest Ethiopia, by following the 2009 World Health Organization efficacy study guidelines from September 2022 to February 2023. Patients with uncomplicated falciparum malaria were conveniently selected and treated with a standard dose of artemether-lumefantrine, along with a single low dose of primaquine. Then clinical and parasitological responses and haemoglobin levels were assessed during the 28-day scheduled follow-up. Blood films were examined and asexual parasites were quantified; axillary temperature was measured; and drug adverse events were assessed throughout the follow-up. Finally, the drug efficacy (adequate clinical and parasitological response) was determined by Kaplan–Meier and per-protocol analyses. The data were analysed using the WHO Excel spreadsheet and SPSS version 25 software. Results: The success rates of PCR uncorrected and corrected Kaplan–Meier analysis on day 28 were 95.8% (95% CI 87.5–98.6) and 97.3% (95% CI 89.4–99.3), respectively. The per-protocol PCR uncorrected and corrected adequate clinical and parasitological responses were 95.5% (95% CI 87.5–99.1) and 97% (95% CI 89.5–99.6), respectively. On day-3, 97% of study participants were free of asexual parasitaemia, and all of them were fever-free on day-2. All of the gametocyte-positive patients at baseline were found to be negative for gametocytes on day-2. Moreover, the baseline mean hemoglobin of 13.10 g/dl increased slightly on day-14 to 13.27 g/dl but significantly on day-28 to 13.69 g/dl in a paired sample t test. All adverse events reported were mild. Conclusion: Artemether-lumefantrine continued to be an efficacious and safe drug for the treatment of uncomplicated Plasmodium falciparum malaria at the Teda Health Centre. Trial registration: unique ID# PACTR202309773069812 at https://pactr.samrc.ac.za on September 1, 2023. [ABSTRACT FROM AUTHOR]

Background: The burden of malaria persists in sub-Saharan Africa and the emergence of artemisinin resistance has introduced complexity to control efforts. Monitoring the efficacy of artemisinin-based treatment for malaria is crucial to address this challenge. This study assessed treatment efficacy of artemether-lumefantrine (AL) and genetic diversity of Plasmodium falciparum isolates in a Nigerian population. Methods: Participants presenting with clinical symptoms of uncomplicated malaria at a health centre in Lagos, Nigeria, were screened for P. falciparum. Enrolled participants were treated with AL and monitored through scheduled check-up visits, clinical and laboratory examinations for 28 days. Parasite clearance and genetic diversity were assessed through polymerase chain reaction (PCR) analysis of merozoite surface proteins (msp1 and msp2). The prevalence of drug resistance mutations was assessed by P. falciparum multidrug resistance gene 1 (mdr1) genotyping followed by P. falciparum ubiquitin-specific protease 1 (ubp1) gene sequencing. Results: The PCR-uncorrected treatment outcome revealed 94.4% adequate clinical and parasitological response (ACPR) and 5.6% late parasitological failure (LPF) rates. After PCR correction, no suspected LPF case was detected and ACPR 67/67 (100%) was achieved in all the individuals. Moreover, a high prevalence of wild-type alleles for mdr1 N86Y (93.7%), and mdr1 D1246Y (87.5%) was observed. Genetic diversity analysis revealed predominant K1 allelic family for msp1 (90.2%) and FC27 for msp2 (64.4%). Estimated multiplicity of infection (MOI) was 1.7, with the highest MOI observed in the 5–15 years age group. ubp1 sequence analysis identified one nonsynonymous E1528D polymorphism at a low frequency (1.6%). Conclusion: The study demonstrated sustained efficacy of AL for treating uncomplicated P. falciparum malaria. Genetic diversity analysis revealed various allelic types, suggesting occurrences of polyclonal infections. Nonetheless, the detection of a significant ubp1 polymorphism could have future implications for the epidemiology of anti-malarial drug resistance in the population. [ABSTRACT FROM AUTHOR]

Background: Malaria remains a major global health problem although there was a remarkable achievement between 2000 and 2015. Malaria drug resistance, along with several other factors, presents a significant challenge to malaria control and elimination efforts. Numerous countries in sub-Saharan Africa have documented the presence of confirmed or potential markers of partial resistance against artemisinin, the drug of choice for the treatment of uncomplicated Plasmodium falciparum malaria. The World Health Organization (WHO) recommends regular surveillance of artemisinin therapeutic efficacy to inform policy decisions. Methods: This study aimed to evaluate the therapeutic efficacy of artemether-lumefantrine (AL), which is the first-line treatment for uncomplicated P. falciparum malaria in Ethiopia since 2004. Using a single-arm prospective evaluation design, the study assessed the clinical and parasitological responses of patients with uncomplicated P. falciparum malaria in Metehara Health Centre, central-east Ethiopia. Out of 2332 malaria suspects (1187 males, 1145 females) screened, 80 (50 males, 30 females) were enrolled, followed up for 28 days, and 73 (44 males, 29 females) completed the follow up. The study was conducted and data was analysed by employing the per-protocol and Kaplan–Meier analyses following the WHO Malaria Therapeutic Efficacy Evaluation Guidelines 2009. Results: The results indicated rapid parasite clearance and resolution of clinical symptoms, with all patients achieving complete recovery from asexual parasitaemia and fever by day (D) 3. The prevalence of gametocytes decreased from 6.3% on D0 to 2.5% on D2, D3, D7, and ultimately achieving complete clearance afterward. Conclusion: The overall cure rate for AL treatment was 100%, demonstrating its high efficacy in effectively eliminating malaria parasites in patients. No serious adverse events related to AL treatment were reported during the study, suggesting its safety and tolerability among the participants. These findings confirm that AL remains a highly efficacious treatment for uncomplicated P. falciparum malaria in the study site after 20 years of its introduction in Ethiopia. [ABSTRACT FROM AUTHOR]

Abstract Background Monitoring therapeutic efficacy is important to ensure the efficacy of artemisinin-based combination therapy (ACT) for malaria. The current first-line treatment for uncomplicated malaria recommended by the National Malaria Control Program in Niger is artemether–lumefantrine (AL). In 2020, an in vivo study was carried out to evaluate clinical and parasitological responses to AL as well as the molecular resistance to the drug in three sentinel sites: Agadez, Tessaoua and Gaya, in Niger. Methods A multi-center, single-arm trial was conducted according to the 28-day World Health Organization (WHO) 2009 therapeutic efficacy study protocol. Children between 6 months and 15 years with confirmed uncomplicated Plasmodium falciparum infection and 1000–200,000 asexual parasites/μL of blood were enrolled and followed up for 28 days. Uncorrected and PCR-corrected efficacy results at day 28 were calculated, and molecular correction was performed by genotyping the msp1, msp2, and glurp genes. The pfk13, pfdhfr, pfdhps, pfcrt and pfmdr genes were analyzed by PCR and Sanger sequencing. The Kaplan–Meier curve assessed parasite clearance. Results A total of 255 patients were enrolled in the study. The adequate clinical and parasitological response after PCR correction was 98.9% (95% CI 96.4–101.0%), 92.2% (85.0–98.5%) and 97.1% (93.1–101.0%) in Gaya, Tessaoua and Agadez, respectively. No adverse events were observed. Ten mutations (SNP) were found, including 7 synonyms (K248K, G690G, E691E, E612E, C469C, G496G, P718P) and 3 non-synonyms (N594K, R255K, V714S). Two mutations emerged: N594K and V714S. The R255K mutation detected in Southeast Asia was also detected. The pfdhpsK540E and pfdhfrI164L mutations associated with high levels of resistance are absent. There is a reversal of chloroquine resistance. Conclusion The study findings indicate that AL is effective and well tolerated for the treatment of uncomplicated malaria in three sites in Niger. The emergence of a pfk13 mutation requires additional testing such as the Ring Stage Assay and CRISPR/Cas9 to confirm the role of these emerging mutations. Trial registration NCT05070520, October 7, 2021.

Abstract Background Despite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether–lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy. Methods Patients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR–RFLP. Results A total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0–2666/μL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors. Conclusions The study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites.

Abstract Background Artemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization (WHO) recommends regular assessment and monitoring of the efficacy of the first-line treatment, specifically considering that artemisinin resistance has been confirmed in the Greater Mekong sub-region. This study's main aim was to assess the efficacy and safety of AL for treating uncomplicated P. falciparum malaria in Tanzania. Methods This was a single-arm prospective antimalarial drug efficacy trial conducted in four of the eight National Malaria Control Programme (NMCP) sentinel sites in 2019. The trial was carried out in outpatient health facilities in Karume-Mwanza region, Ipinda-Mbeya region, Simbo-Tabora region, and Nagaga-Mtwara region. Children aged six months to 10 years with microscopy confirmed uncomplicated P. falciparum malaria who met the inclusion criteria were recruited based on the WHO protocol. The children received AL (a 6-dose regimen of AL twice daily for three days). Clinical and parasitological parameters were monitored during follow-up over 28 days to evaluate drug efficacy. Results A total of 628 children were screened for uncomplicated malaria, and 349 (55.6%) were enrolled between May and September 2019. Of the enrolled children, 343 (98.3%) completed the 28-day follow-up or attained the treatment outcomes. There were no early treatment failures; recurrent infections during follow-up were common at two sites (Karume 29.5%; Simbo 18.2%). PCR-corrected adequate clinical and parasitological response (ACPR) by survival analysis to AL on day 28 of follow-up varied from 97.7% at Karume to 100% at Ipinda and Nagaga sites. The commonly reported adverse events were cough, skin pallor, and abdominal pain. The drug was well tolerated, and no serious adverse event was reported. Conclusion This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria in Tanzania in 2019. The high recurrent infections were mainly due to new infections, highlighting the potential role of introducing alternative artemisinin-based combinations that offer improved post-treatment prophylaxis, such as artesunate-amodiaquine (ASAQ).

Abstract Background Artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the currently recommended first- and second-line therapies for uncomplicated Plasmodium falciparum infections in Togo. This study assessed the efficacy of these combinations, the proportion of Day3-positive patients (D3 +), the proportion of molecular markers associated with P. falciparum resistance to anti-malarial drugs, and the variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). Methods A single arm prospective study evaluating the efficacy of AL and DP was conducted at two sites (Kouvé and Anié) from September 2021 to January 2022. Eligible children were enrolled, randomly assigned to treatment at each site and followed up for 42 days after treatment initiation. The primary endpoint was polymerase chain reaction (PCR) adjusted adequate clinical and parasitological response (ACPR). At day 0, samples were analysed for mutations in the Pfkelch13, Pfcrt, Pfmdr-1, dhfr, dhps, and deletions in the hrp2/hrp3 genes. Results A total of 179 and 178 children were included in the AL and DP groups, respectively. After PCR correction, cure rates of patients treated with AL were 97.5% (91.4–99.7) at day 28 in Kouvé and 98.6% (92.4–100) in Anié, whereas 96.4% (CI 95%: 89.1–98.8) and 97.3% (CI 95%: 89.5–99.3) were observed at day 42 in Kouvé and Anié, respectively. The cure rates of patients treated with DP at day 42 were 98.9% (CI 95%: 92.1–99.8) in Kouvé and 100% in Anié. The proportion of patients with parasites on day 3 (D3 +) was 8.5% in AL and 2.6% in DP groups in Anié and 4.3% in AL and 2.1% DP groups in Kouvé. Of the 357 day 0 samples, 99.2% carried the Pfkelch13 wild-type allele. Two isolates carried nonsynonymous mutations not known to be associated with artemisinin partial resistance (ART-R) (A578S and A557S). Most samples carried the Pfcrt wild-type allele (97.2%). The most common Pfmdr-1 allele was the single mutant 184F (75.6%). Among dhfr/dhps mutations, the quintuple mutant haplotype N51I/C59R/S108N + 437G/540E, which is responsible for SP treatment failure in adults and children, was not detected. Single deletions in hrp2 and hrp3 genes were detected in 1/357 (0.3%) and 1/357 (0.3%), respectively. Dual hrp2/hrp3 deletions, which could affect the performances of HRP2-based RDTs, were not observed. Conclusion The results of this study confirm that the AL and DP treatments are highly effective. The absence of the validated Pfkelch13 mutants in the study areas suggests the absence of ART -R, although a significant proportion of D3 + cases were found. The absence of dhfr/dhps quintuple or sextuple mutants (quintuple + 581G) supports the continued use of SP for IPTp during pregnancy and in combination with amodiaquine for seasonal malaria chemoprevention. Trial registration: ACTRN12623000344695.

Background: Monitoring therapeutic efficacy is important to ensure the efficacy of artemisinin-based combination therapy (ACT) for malaria. The current first-line treatment for uncomplicated malaria recommended by the National Malaria Control Program in Niger is artemether–lumefantrine (AL). In 2020, an in vivo study was carried out to evaluate clinical and parasitological responses to AL as well as the molecular resistance to the drug in three sentinel sites: Agadez, Tessaoua and Gaya, in Niger. Methods: A multi-center, single-arm trial was conducted according to the 28-day World Health Organization (WHO) 2009 therapeutic efficacy study protocol. Children between 6 months and 15 years with confirmed uncomplicated Plasmodium falciparum infection and 1000–200,000 asexual parasites/μL of blood were enrolled and followed up for 28 days. Uncorrected and PCR-corrected efficacy results at day 28 were calculated, and molecular correction was performed by genotyping the msp1, msp2, and glurp genes. The pfk13, pfdhfr, pfdhps, pfcrt and pfmdr genes were analyzed by PCR and Sanger sequencing. The Kaplan–Meier curve assessed parasite clearance. Results: A total of 255 patients were enrolled in the study. The adequate clinical and parasitological response after PCR correction was 98.9% (95% CI 96.4–101.0%), 92.2% (85.0–98.5%) and 97.1% (93.1–101.0%) in Gaya, Tessaoua and Agadez, respectively. No adverse events were observed. Ten mutations (SNP) were found, including 7 synonyms (K248K, G690G, E691E, E612E, C469C, G496G, P718P) and 3 non-synonyms (N594K, R255K, V714S). Two mutations emerged: N594K and V714S. The R255K mutation detected in Southeast Asia was also detected. The pfdhpsK540E and pfdhfrI164L mutations associated with high levels of resistance are absent. There is a reversal of chloroquine resistance. Conclusion: The study findings indicate that AL is effective and well tolerated for the treatment of uncomplicated malaria in three sites in Niger. The emergence of a pfk13 mutation requires additional testing such as the Ring Stage Assay and CRISPR/Cas9 to confirm the role of these emerging mutations. Trial registration NCT05070520, October 7, 2021. [ABSTRACT FROM AUTHOR]

Background: Despite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether–lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy. Methods: Patients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR–RFLP. Results: A total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0–2666/μL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors. Conclusions: The study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites. [ABSTRACT FROM AUTHOR]

Background: Artemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization (WHO) recommends regular assessment and monitoring of the efficacy of the first-line treatment, specifically considering that artemisinin resistance has been confirmed in the Greater Mekong sub-region. This study's main aim was to assess the efficacy and safety of AL for treating uncomplicated P. falciparum malaria in Tanzania. Methods: This was a single-arm prospective antimalarial drug efficacy trial conducted in four of the eight National Malaria Control Programme (NMCP) sentinel sites in 2019. The trial was carried out in outpatient health facilities in Karume-Mwanza region, Ipinda-Mbeya region, Simbo-Tabora region, and Nagaga-Mtwara region. Children aged six months to 10 years with microscopy confirmed uncomplicated P. falciparum malaria who met the inclusion criteria were recruited based on the WHO protocol. The children received AL (a 6-dose regimen of AL twice daily for three days). Clinical and parasitological parameters were monitored during follow-up over 28 days to evaluate drug efficacy. Results: A total of 628 children were screened for uncomplicated malaria, and 349 (55.6%) were enrolled between May and September 2019. Of the enrolled children, 343 (98.3%) completed the 28-day follow-up or attained the treatment outcomes. There were no early treatment failures; recurrent infections during follow-up were common at two sites (Karume 29.5%; Simbo 18.2%). PCR-corrected adequate clinical and parasitological response (ACPR) by survival analysis to AL on day 28 of follow-up varied from 97.7% at Karume to 100% at Ipinda and Nagaga sites. The commonly reported adverse events were cough, skin pallor, and abdominal pain. The drug was well tolerated, and no serious adverse event was reported. Conclusion: This study showed that AL had adequate efficacy and safety for the treatment of uncomplicated falciparum malaria in Tanzania in 2019. The high recurrent infections were mainly due to new infections, highlighting the potential role of introducing alternative artemisinin-based combinations that offer improved post-treatment prophylaxis, such as artesunate-amodiaquine (ASAQ). [ABSTRACT FROM AUTHOR]

Background: Artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the currently recommended first- and second-line therapies for uncomplicated Plasmodium falciparum infections in Togo. This study assessed the efficacy of these combinations, the proportion of Day3-positive patients (D3 +), the proportion of molecular markers associated with P. falciparum resistance to anti-malarial drugs, and the variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). Methods: A single arm prospective study evaluating the efficacy of AL and DP was conducted at two sites (Kouvé and Anié) from September 2021 to January 2022. Eligible children were enrolled, randomly assigned to treatment at each site and followed up for 42 days after treatment initiation. The primary endpoint was polymerase chain reaction (PCR) adjusted adequate clinical and parasitological response (ACPR). At day 0, samples were analysed for mutations in the Pfkelch13, Pfcrt, Pfmdr-1, dhfr, dhps, and deletions in the hrp2/hrp3 genes. Results: A total of 179 and 178 children were included in the AL and DP groups, respectively. After PCR correction, cure rates of patients treated with AL were 97.5% (91.4–99.7) at day 28 in Kouvé and 98.6% (92.4–100) in Anié, whereas 96.4% (CI 95%: 89.1–98.8) and 97.3% (CI 95%: 89.5–99.3) were observed at day 42 in Kouvé and Anié, respectively. The cure rates of patients treated with DP at day 42 were 98.9% (CI 95%: 92.1–99.8) in Kouvé and 100% in Anié. The proportion of patients with parasites on day 3 (D3 +) was 8.5% in AL and 2.6% in DP groups in Anié and 4.3% in AL and 2.1% DP groups in Kouvé. Of the 357 day 0 samples, 99.2% carried the Pfkelch13 wild-type allele. Two isolates carried nonsynonymous mutations not known to be associated with artemisinin partial resistance (ART-R) (A578S and A557S). Most samples carried the Pfcrt wild-type allele (97.2%). The most common Pfmdr-1 allele was the single mutant 184F (75.6%). Among dhfr/dhps mutations, the quintuple mutant haplotype N51I/C59R/S108N + 437G/540E, which is responsible for SP treatment failure in adults and children, was not detected. Single deletions in hrp2 and hrp3 genes were detected in 1/357 (0.3%) and 1/357 (0.3%), respectively. Dual hrp2/hrp3 deletions, which could affect the performances of HRP2-based RDTs, were not observed. Conclusion: The results of this study confirm that the AL and DP treatments are highly effective. The absence of the validated Pfkelch13 mutants in the study areas suggests the absence of ART -R, although a significant proportion of D3 + cases were found. The absence of dhfr/dhps quintuple or sextuple mutants (quintuple + 581G) supports the continued use of SP for IPTp during pregnancy and in combination with amodiaquine for seasonal malaria chemoprevention. Trial registration: ACTRN12623000344695. [ABSTRACT FROM AUTHOR]

Abstract Background Artemisinin-based combination therapy (ACT) has been effective in the supervised treatment of uncomplicated malaria in Ghana. Since ACT usage is primarily unsupervised, this study aimed to determine the effectiveness of artemether–lumefantrine (AL) for treating malaria patients in two transmission settings in Ghana. Methods Eighty-four individuals with uncomplicated Plasmodium falciparum malaria were recruited from Lekma Hospital (LH) in Accra (low-transmission area; N = 28), southern Ghana, and King’s Medical Centre (KMC) in Kumbungu (high-transmission area; N = 56), northern Ghana. Participants were followed up for 28 days after unsupervised treatment with AL. The presence of asexual parasites was determined by microscopic examination of Giemsa-stained blood smears. Plasmodium species identification was confirmed using species-specific primers targeting the 18S rRNA gene. Parasite recrudescence or reinfection was determined by genotyping the Pfmsp 1 and Pfmsp 2 genes. Results After AL treatment, 3.6% (2/56) of the patients from KMC were parasitaemic on day 3 compared to none from the LH patients. One patient from KMC with delayed parasite clearance on day 3 remained parasite-positive by microscopy on day 7 but was parasite-free by day 14. While none of the patients from LH experienced parasite recurrence during the 28-day follow-up, three and two patients from KMC had recurrent parasitaemia on days 21 and 28, respectively. Percentage reduction in parasite densities from day 1, 2, and 3 for participants from the KMC was 63.2%, 89.5%, and 84.5%. Parasite densities for participants from the LH reduced from 98.2%, 99.8% on day 1, and 2 to 100% on day 3. The 28-day cumulative incidence rate of treatment failure for KMC was 12.8% (95% confidence interval: 1.9–23.7%), while the per-protocol effectiveness of AL in KMC was 89.47%. All recurrent cases were assigned to recrudescence after parasite genotyping by Pfmsp 1 and Pfmsp 2. Conclusion While AL is efficacious in treating uncomplicated malaria in Ghana, when taken under unsupervised conditions, it showed an 89.4% PCR-corrected cure rate in northern Ghana, which is slightly below the WHO-defined threshold.

Background: Artemisinin-based combination therapy (ACT) has been effective in the supervised treatment of uncomplicated malaria in Ghana. Since ACT usage is primarily unsupervised, this study aimed to determine the effectiveness of artemether–lumefantrine (AL) for treating malaria patients in two transmission settings in Ghana. Methods: Eighty-four individuals with uncomplicated Plasmodium falciparum malaria were recruited from Lekma Hospital (LH) in Accra (low-transmission area; N = 28), southern Ghana, and King's Medical Centre (KMC) in Kumbungu (high-transmission area; N = 56), northern Ghana. Participants were followed up for 28 days after unsupervised treatment with AL. The presence of asexual parasites was determined by microscopic examination of Giemsa-stained blood smears. Plasmodium species identification was confirmed using species-specific primers targeting the 18S rRNA gene. Parasite recrudescence or reinfection was determined by genotyping the Pfmsp 1 and Pfmsp 2 genes. Results: After AL treatment, 3.6% (2/56) of the patients from KMC were parasitaemic on day 3 compared to none from the LH patients. One patient from KMC with delayed parasite clearance on day 3 remained parasite-positive by microscopy on day 7 but was parasite-free by day 14. While none of the patients from LH experienced parasite recurrence during the 28-day follow-up, three and two patients from KMC had recurrent parasitaemia on days 21 and 28, respectively. Percentage reduction in parasite densities from day 1, 2, and 3 for participants from the KMC was 63.2%, 89.5%, and 84.5%. Parasite densities for participants from the LH reduced from 98.2%, 99.8% on day 1, and 2 to 100% on day 3. The 28-day cumulative incidence rate of treatment failure for KMC was 12.8% (95% confidence interval: 1.9–23.7%), while the per-protocol effectiveness of AL in KMC was 89.47%. All recurrent cases were assigned to recrudescence after parasite genotyping by Pfmsp 1 and Pfmsp 2. Conclusion: While AL is efficacious in treating uncomplicated malaria in Ghana, when taken under unsupervised conditions, it showed an 89.4% PCR-corrected cure rate in northern Ghana, which is slightly below the WHO-defined threshold. [ABSTRACT FROM AUTHOR]

Background Artemisinin-based combination therapies (ACTs) are recommended as first-line treatment against uncomplicated Plasmodium falciparum infection. Mutations in the PfKelch13 (PF3D7_1343700) gene led to resistance to artemisinin in Southeast Asia. Mutations in the Pfcoronin (PF3D7_1251200) gene confer reduced artemisinin susceptibility in vitro to an African Plasmodium strain, but their role in clinical resistance has not been established. Methods We conducted a retrospective observational study of Israeli travellers returning from sub-Saharan Africa with P. falciparum malaria, including patients with artemether–lumefantrine (AL) failure. Blood samples from all malaria-positive patients are delivered to the national Parasitology Reference Laboratory along with personal information. Confirmation of malaria, species identification and comparative parasite load analysis were performed using real-time PCR. DNA extractions from stored leftover samples were analysed for the presence of mutations in Pfkelch13 and Pfcoronin. Age, weight, initial parasitaemia level and Pfcoronin status were compared in patients who failed treatment vs responders. Results During 2009–2020, 338 patients had P. falciparum malaria acquired in Africa. Of those, 15 (24–69 years old, 14 males) failed treatment with AL. Four were still parasitemic at the end of treatment, and 11 had malaria recrudescence. Treatment failure rates were 0% during 2009–2012, 9.1% during 2013–2016 and 17.4% during 2017–2020. In all patients, the Pfkelch13 propeller domain had a wild-type sequence. We did find the P76S mutation in the propeller domain of Pfcoronin in 4/15 (28.6%) of the treatment-failure cases compared to only 3/56 (5.5%) in the successfully treated patients (P  = 0.027). Conclusion AL treatment failure emergence was not associated with mutations in Pfkelch13. However, P76S mutation in the Pfcoronin gene was more frequently present in the treatment-failure group and merits further investigation. The increase of malaria incidence in sub-Saharan-Africa partly attributed to the COVID-19 pandemic might also reflect a wider spread of ACT resistance. [ABSTRACT FROM AUTHOR]

Abstract Background Artesunate–amodiaquine (AS–AQ) and artemether–lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). Methods A single-arm prospective study assessing the efficacy of AS–AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS–AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes. Results By the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2–100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates. Conclusion The results of this study confirm that AS–AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance. Trial registration ACTRN12622001476729

Treatment failure of Artemether-Lumefantrine drug in treating uncomplicated malaria is increasing in many endemic malaria countries. Tolerance, recrudescence, and resistance of plasmodium falciparum and plasmodium vivax parasites to the drug are increasing all over the world. We aimed to measure the treatment failure of antimalarial Artemether-Lumefantrine (Coartem) and it is contributing factors in uncomplicated malaria among adults in health centers. This study was a descriptive cross-sectional health-facility-based study conducted from the first of April to the end of June 2022 and included 166 malaria patients with positive test results for malaria visited health centers. 9.6% of malaria patients were not responding to coartem, 6.0% of them were plasmodium falciparum, 2.4% were plasmodium vivax, and 1.2 were mixed infections. Thirty-one percent of those not taking the drug with the fatty meal tested positive for malaria after two weeks of receiving coartem, and 25% of those not adherent to the treatment timetable have not cleared the parasite despite receiving coartem. The results showed that nearly one-third of the patients received Coartem without laboratory tests for malaria. Artemether-Lumefantrine is becoming less effective in the treatment of uncomplicated malaria among adults in Khartoum state, Sudan. Prospective studies are needed to assess the frequency of treatment failure and the contributing factors that assist in decreasing drug efficacy. We also encourage pharmacists not to give antimalarial treatment without a medical prescription and a positive test. [ABSTRACT FROM AUTHOR]

Abstract Background Substandard anti-malarial agents pose a significant challenge to effective malaria control and elimination efforts especially in sub-Saharan Africa. The quality of anti-malarials in most low-and-middle income countries (LMICs) is affected by several factors including inadequate regulation and limited resources. In this study, the pharmacopeial quality of artemether–lumefantrine (AL) in low and high malaria transmission settings in Uganda was assessed. Methods This was a cross-sectional study conducted among randomly selected private drug outlets. The AL anti-malarials available in drug outlets were purchased using overt method. The samples were screened for quality using visual inspection, weight uniformity, content assay and dissolution tests. The assay test was done using liquid chromatography–mass spectrometry (LC–MS). The samples were considered substandard if the active pharmaceutical ingredient (API) content was outside 90–110% range of the label claim. Dissolution test was conducted following United States Pharmacopoeia (USP) method. Data was analysed using descriptive statistics and presented as means with standard deviations, frequencies, and proportions. Correlation between medicine quality and independent variables was determined using Fisher’s exact test of independence at 95% level of significance. Results A total of 74 AL anti-malarial samples were purchased from high (49/74; 66.2%) and low (25/74; 33.8%) malaria transmission settings. The most common batch of AL was LONART, 32.4% (24/74), with 33.8% (25/74) being ‘Green leaf’. Overall prevalence of substandard quality artemether–lumefantrine was 18.9% (14/74; 95% CI: 11.4–29.7). Substandard quality AL was significantly associated with setting (p = 0.002). A total of 10 samples (13.5%) failed artemether content assay test while, 4 samples (5.4%, 4/74) failed the lumefantrine assay test. One sample from a high malaria transmission setting failed both artemether and lumefantrine assay content test. Of the samples that failed artemether assay test, 90% had low (

Abstract Background Malaria remains a public health concern globally. Resistance to anti-malarial drugs has consistently threatened the gains in controlling the malaria parasites. Currently, artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the treatment regimens against Plasmodium falciparum infections in many African countries, including Kenya. Recurrent infections have been reported in patients treated with AL or DP, suggesting the possibility of reinfection or parasite recrudescence associated with the development of resistance against the two therapies. The Plasmodium falciparum cysteine desulfurase IscS (Pfnfs1) K65 selection marker has previously been associated with decreased lumefantrine susceptibility. This study evaluated the frequency of the Pfnfs1 K65 resistance marker and associated K65Q resistant allele in recurrent infections collected from P. falciparum-infected individuals living in Matayos, Busia County, in western Kenya. Methods Archived dried blood spots (DBS) of patients with recurrent malaria infection on clinical follow-up days after treatment with either AL or DP were used in the study. After extraction of genomic DNA, PCR amplification and sequencing analysis were employed to determine the frequencies of the Pfnfs1 K65 resistance marker and K65Q mutant allele in the recurrent infections. Plasmodium falciparum msp1 and P. falciparum msp2 genetic markers were used to distinguish recrudescent infections from new infections. Results The K65 wild-type allele was detected at a frequency of 41% while the K65Q mutant allele was detected at a frequency of 22% in the recurrent samples. 58% of the samples containing the K65 wild-type allele were AL treated samples and while 42% were DP treated samples. 79% of the samples with the K65Q mutation were AL treated samples and 21% were DP treated samples. The K65 wild-type allele was detected in three recrudescent infections (100%) identified from the AL treated samples. The K65 wild-type allele was detected in two recrudescent DP treated samples (67%) while the K65Q mutant allele was identified in one DP treated (33%) recrudescent sample. Conclusions The data demonstrate a higher frequency of the K65 resistance marker in patients with recurrent infection during the study period. The study underscores the need for consistent monitoring of molecular markers of resistance in regions of high malaria transmission.

Abstract Background In Nigeria, declining responsiveness to artemether–lumefantrine (AL), the artemisinin-based combination therapy (ACT) of choice since 2005, has been reported. Pyronaridine–artesunate (PA) is a newer fixed-dose ACT recently prequalified by the WHO for the treatment of uncomplicated falciparum malaria. However, PA data from the Nigerian pediatric population is scarce. Therefore, the efficacy and safety of PA and AL using the WHO 28-day anti-malarial therapeutic efficacy study protocol in Ibadan, southwest Nigeria, were compared. Methods In an open-labelled, randomized, controlled clinical trial, 172 children aged 3–144 months with a history of fever and microscopically confirmed uncomplicated Plasmodium falciparum malaria were enrolled in southwest Nigeria. Enrollees were randomly assigned to receive PA or AL at standard dosages according to body weight for 3 days. Venous blood was obtained for hematology, blood chemistry, and liver function tests on days 0, 3, 7, and 28 as part of the safety evaluation. Results 165 (95.9%) of the enrolled individuals completed the study. About half (52.3%; 90/172) of enrollees were male. Eighty-seven (50.6%) received AL, while 85 (49.4%) received PA. Day 28, adequate clinical and parasitological response for PA was 92.7% [(76/82) 95% CI 83.1, 95.9] and 71.1% [(59/83) 95% CI 60.4, 79.9] for AL (0.001). Fever and parasite clearance were similar in both groups. Two of six and eight of 24 parasite recurrences were observed among PA- and AL-treated children, respectively. PCR-corrected Day-28 cure rates for PA were 97.4% (76/78) and 88.1% (59/67) for AL (= 0.04) in the per-protocol population after new infections were censored. Hematological recovery at day 28 was significantly better among PA-treated patients (34.9% 2.8) compared to those treated with AL (33.1% 3.0) (0.002). Adverse events in both treatment arms were mild and similar to the symptoms of malaria infection. Blood chemistry and liver function tests were mostly within normal limits, with an occasional marginal rise. Conclusion PA and AL were well-tolerated. PA was significantly more efficacious than AL in both the PCR-uncorrected and PCR-corrected per-protocol populations during this study. The results of this study support the inclusion of PA in the anti-malarial treatment guidelines in Nigeria. Retrospective trial registration Clinicaltrials.gov: NCT05192265.

Abstract Background Post-artemisinin delayed hemolysis (PADH) is a serious complication in patients who recover from severe malaria after receiving artemisinin-based combined therapy (ACT), including artemether-lumefantrine. In Japan, among the antimalarial drugs recommended by the World Health Organization (WHO) guideline for severe malaria, intravenous quinine gluconate is available only in 29 designated hospitals, and intravenous artesunate is unavailable. Therefore, oral artemether-lumefantrine is occasionally administered as an alternative, even though it may be a suboptimal treatment. In non-endemic settings like Japan, a lack of knowledge of malaria and the side effects, such as post-artemisinin delayed hemolysis caused by the ACT, can have critical consequences. Like our patient, being a primigravida in the early stages of pregnancy is a serious risk factor for severe malaria and must be carefully monitored. Case presentation This report describes a severe case of imported Plasmodium falciparum malaria complicated by fetal loss and prolonged anemia, requiring frequent blood transfusions. The patient was a previously healthy pregnant Japanese female in her 30 s. She developed a high fever 2 days after returning from Nigeria. The patient fulfilled the severe malaria criteria by WHO. On arrival, an abdominal ultrasound incidentally revealed a fetus of 5 week gestational age with a heartbeat in the uterus. Given her pregnancy and the severity of the disease, she was administered intravenous quinine 16 mg/kg as a loading dose. However, the second dose of quinine was not administered due to frequent vomiting and QTc prolongation. We initiated treatment with oral artemether-lumefantrine, and clearance of parasitemia was confirmed by microscopic observation on day 4. Miscarriage was noted on day 6 after admission. Moreover, the patient became feverish again up to 39 °C, and from days 14 to 22, the patient required multiple blood transfusions due to PADH. On day 40, follow-up was discontinued as the hemoglobin level exceeded 10 g/dL. Conclusions In patients who recover from severe malaria after ACT treatment, monitoring the hemoglobin level for at least a month is strongly recommended for prompt identification of PADH. Travelers to malaria-endemic countries, especially primigravida women, should be provided with adequate information on the risk and prevention of infection.

The article discusses the increasing reports of artemether-lumefantrine (AL) treatment failures in treating uncomplicated Plasmodium falciparum infection, particularly in Africa. AL is the most widely used artemisinin-based combination therapy (ACT) and is at the greatest risk of losing efficacy. The article highlights the importance of monitoring antimalarial efficacy in returning travelers, as they can provide valuable insights into the effectiveness of treatments. The study conducted in Israel found that AL failure rates increased over time, and while no concerning mutations were found, the researchers identified a Pfcoronin gene mutation associated with treatment failure. The article emphasizes the need for diversification of antimalarial drug choices to avoid overreliance on a single therapy and to preserve the efficacy of ACTs. [Extracted from the article]

IntroductionLimited information exists on any interactions between hydroxyurea (HU) and antimalarials in sickle cell disease (SCD). We evaluated changes in clinical and laboratory parameters among children with SCD on HU therapy treated with artemether-lumefantrine (AL) for acute uncomplicated malaria (UM).MethodsA prospective, non-randomized, pilot study of 127 children with SCD (23, UM; 104, steady state) were recruited from three hospitals in Accra. UM participants were treated with standard doses of AL and followed up, on days 1, 2, 3, 7, 14, and 28. Venous blood was collected at baseline and follow-up days in participants with UM for determination of malaria parasitaemia, full blood count, reticulocytes, and clinical chemistry. Further, Plasmodium falciparum identification of rapid diagnostic test (RDT) positive samples was done using nested polymerase chain reaction (PCR).ResultsAmong SCD participants with UM, admission temperature, neutrophils, alanine-aminotransferase, gamma-glutamyl-transferase, and haemoglobin significantly differed between HU recipients (HU+) and steady state, while white blood cell, neutrophils, reticulocytes, bilirubin, urea, and temperature differed significantly between non-HU recipients (no-HU), and steady state. Mean parasitaemia (HU+, 2930.3 vs. no-HU, 1,060, p = 0.74) and adverse events (HU+, 13.9% vs. no-HU, 14.3%), were comparable (p = 0.94). Day 28 reticulocyte count was higher in the HU+ (0.24) (0.17 to 0.37) vs. no-HU, [0.15 (0.09 to 0.27), p = 0.022]. Significant differences in lymphocyte [HU+ 2.74 95% CI (−5.38 to 58.57) vs. no-HU −0.34 (−3.19 to 4.44), p = 0.024]; bilirubin [HU+, −4.44 (−16.36 to 20.74) vs. no-HU −18.37 (−108.79 to −7.16)]; and alanine aminotransferase, [HU+, −4.00 (−48.55 to 6.00) vs. no-HU, 7.00 (−22.00 to 22.00)] were observed during follow up.ConclusionParasite clearance and adverse event occurrence were comparable between SCD children treated with AL irrespective of HU status. However, distinct patterns of changes in laboratory indices suggest the need for larger, more focused studies.

Background: Artesunate–amodiaquine (AS–AQ) and artemether–lumefantrine (AL) are the currently recommended first-and second-line therapies for uncomplicated Plasmodium falciparum infections in Chad. This study assessed the efficacy of these artemisinin-based combinations, proportion of day 3 positive patients, proportions of molecular markers associated with P. falciparum resistance to anti-malarial drugs and variable performance of HRP2-based malaria rapid diagnostic tests (RDTs). Methods: A single-arm prospective study assessing the efficacy of AS–AQ and AL at three sites (Doba, Kelo and Koyom) was conducted between November 2020 to January 2021. Febrile children aged 6 to 59 months with confirmed uncomplicated P. falciparum infection were enrolled sequentially first to AS–AQ and then AL at each site and followed up for 28 days. The primary endpoint was PCR-adjusted adequate clinical and parasitological response (ACPR). Samples collected on day 0 were analysed for mutations in pfkelch13, pfcrt, pfmdr-1, pfdhfr, pfdhps genes and deletions in pfhrp2/pfhrp3 genes. Results: By the end of 28-day follow-up, per-protocol PCR corrected ACPR of 97.8% (CI 95% 88.2–100) in Kelo and 100% in Doba and Kayoma were observed among AL treated patients. For ASAQ, 100% ACPR was found in all sites. All, but one patient, did not have parasites detected on day 3. Out of the 215 day 0 samples, 96.7% showed pfkelch13 wild type allele. Seven isolates carried nonsynonymous mutations not known to be associated artemisinin partial resistance (ART-R). Most of samples had a pfcrt wild type allele (79% to 89%). The most prevalent pfmdr-1 allele detected was the single mutant 184F (51.2%). For pfdhfr and pfdhps mutations, the quintuple mutant allele N51I/C59R/S108N + G437A/540E responsible for SP treatment failures in adults and children was not detected. Single deletion in the pfhrp2 and pfhrp3 gene were detected in 10/215 (4.7%) and 2/215 (0.9%), respectively. Dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, were observed in 5/215 (2.3%) isolates. Conclusion: The results of this study confirm that AS–AQ and AL treatments are highly efficacious in study areas in Chad. The absence of known pfkelch13 mutations in the study sites and the high parasite clearance rate at day 3 suggest the absence of ART-R. The absence of pfdhfr/pfdhps quintuple or sextuple (quintuple + 581G) mutant supports the continued use of SP for IPTp during pregnancy. The presence of parasites with dual pfhrp2/pfhrp3 deletions, potentially threatening the efficacy of HRP2-based RDTs, warrants the continued surveillance. Trial registration ACTRN12622001476729 [ABSTRACT FROM AUTHOR]

This study investigated the effects of co-administration of a commercial juice rich in vitamin C (Vit C) on the antimalarial efficacy of artemether-lumefantrine (AL) in Plasmodium berghei-infected mice. Fifty Balb/c mice were infected with Plasmodium berghei NK65 strain from a donor mouse. Parasitemia was established after 72 h. Animals were grouped into 6 (n = 10) and treated daily for 3 days with normal saline, chloroquine, artemether-lumefantrine (AL), AL plus 50% commercial juice (CJ), and AL plus 50% Vit C supplementation in drinks ad libitum, respectively. Body weight, parasitemia levels, and mean survival time were determined. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), nitrite, malondialdehyde, reduced glutathione (GSH), catalase, and superoxide dismutase (SOD) were determined in the serum and liver tissues. Spleen histopathological changes were determined by H&E staining. Parasitemia was cleared by administration of AL and was not affected by Vit C and CJ supplementation. Vit C significantly prevented body weight reduction in AL-treated mice. CJ and Vit C supplementation to AL-treated mice significantly improved survival proportion compared with AL alone animals. Vit C and CJ supplementation significantly improved reduction of TNF-α, IL-6, and malondialdehyde, and increased GSH, CAT, and SOD in AL-treated mice. Spleen cell degeneration and presence of malaria pigment were reduced in AL-treated animals. The results suggest that ad libitum co-administration of commercial juice and vitamin C with artemether-lumefantrine does not impair its antimalarial efficacy but rather improved antioxidant and anti-inflammatory effects in mice. [ABSTRACT FROM AUTHOR]

Abstract Background In 2004, Ethiopia adopted artemether-lumefantrine (AL, Coartem®) as first-line treatment for the management of uncomplicated Plasmodium falciparum malaria. Continuous monitoring of AL therapeutic efficacy is crucial in Ethiopia, as per the World Health Organization (WHO) recommendation. This study aimed to assess the therapeutic efficacy of AL in the treatment of uncomplicated P. falciparum infection. Methods A 28 day onearm, prospective evaluation of the clinical and parasitological response to AL was conducted at Shecha Health Centre, Arba Minch town, Southern Ethiopia. Patients were treated with six-dose regimen of AL over three days and monitored for 28 days with clinical and laboratory assessments. Participant recruitment and outcome classification was done in accordance with the 2009 WHO methods for surveillance of anti-malarial drug efficacy guidelines. Results A total of 88 study participants were enrolled and 69 of them completed the study with adequate clinical and parasitological response. Two late parasitological failures were observed, of which one was classified as a recrudescence by polymerase chain reaction (PCR). The PCRcorrected cure rate was 98.6% (95% CI 92.3–100). AL demonstrated a rapid parasite and fever clearance with no parasitaemia on day 2 and febrile cases on day 3. Gametocyte clearance was complete by day three. No serious adverse events were reported during the 28 days follow-up. Conclusion The study demonstrated high therapeutic efficacy and good safety profile of AL. This suggests the continuation of AL as the first-line drug for the treatment of uncomplicated P. falciparum malaria in Ethiopia. Periodic therapeutic efficacy studies and monitoring of markers of resistance are recommended for early detection of resistant parasites.

Background: Substandard anti-malarial agents pose a significant challenge to effective malaria control and elimination efforts especially in sub-Saharan Africa. The quality of anti-malarials in most low-and-middle income countries (LMICs) is affected by several factors including inadequate regulation and limited resources. In this study, the pharmacopeial quality of artemether–lumefantrine (AL) in low and high malaria transmission settings in Uganda was assessed. Methods: This was a cross-sectional study conducted among randomly selected private drug outlets. The AL anti-malarials available in drug outlets were purchased using overt method. The samples were screened for quality using visual inspection, weight uniformity, content assay and dissolution tests. The assay test was done using liquid chromatography–mass spectrometry (LC–MS). The samples were considered substandard if the active pharmaceutical ingredient (API) content was outside 90–110% range of the label claim. Dissolution test was conducted following United States Pharmacopoeia (USP) method. Data was analysed using descriptive statistics and presented as means with standard deviations, frequencies, and proportions. Correlation between medicine quality and independent variables was determined using Fisher's exact test of independence at 95% level of significance. Results: A total of 74 AL anti-malarial samples were purchased from high (49/74; 66.2%) and low (25/74; 33.8%) malaria transmission settings. The most common batch of AL was LONART, 32.4% (24/74), with 33.8% (25/74) being 'Green leaf'. Overall prevalence of substandard quality artemether–lumefantrine was 18.9% (14/74; 95% CI: 11.4–29.7). Substandard quality AL was significantly associated with setting (p = 0.002). A total of 10 samples (13.5%) failed artemether content assay test while, 4 samples (5.4%, 4/74) failed the lumefantrine assay test. One sample from a high malaria transmission setting failed both artemether and lumefantrine assay content test. Of the samples that failed artemether assay test, 90% had low (< 90%) artemether content. All the samples passed visual inspection and dissolution tests. Conclusion: Artemether–lumefantrine agents, the recommended first-line treatment for uncomplicated malaria with APIs outside the recommended pharmacopeial content assay limit is common especially in high malaria transmission settings. There is need for continuous surveillance and monitoring of the quality of artemisinin-based anti-malarials across the country by the drug regulatory agency. [ABSTRACT FROM AUTHOR]

Background: Malaria remains a public health concern globally. Resistance to anti-malarial drugs has consistently threatened the gains in controlling the malaria parasites. Currently, artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) are the treatment regimens against Plasmodium falciparum infections in many African countries, including Kenya. Recurrent infections have been reported in patients treated with AL or DP, suggesting the possibility of reinfection or parasite recrudescence associated with the development of resistance against the two therapies. The Plasmodium falciparum cysteine desulfurase IscS (Pfnfs1) K65 selection marker has previously been associated with decreased lumefantrine susceptibility. This study evaluated the frequency of the Pfnfs1 K65 resistance marker and associated K65Q resistant allele in recurrent infections collected from P. falciparum-infected individuals living in Matayos, Busia County, in western Kenya. Methods: Archived dried blood spots (DBS) of patients with recurrent malaria infection on clinical follow-up days after treatment with either AL or DP were used in the study. After extraction of genomic DNA, PCR amplification and sequencing analysis were employed to determine the frequencies of the Pfnfs1 K65 resistance marker and K65Q mutant allele in the recurrent infections. Plasmodium falciparum msp1 and P. falciparum msp2 genetic markers were used to distinguish recrudescent infections from new infections. Results: The K65 wild-type allele was detected at a frequency of 41% while the K65Q mutant allele was detected at a frequency of 22% in the recurrent samples. 58% of the samples containing the K65 wild-type allele were AL treated samples and while 42% were DP treated samples. 79% of the samples with the K65Q mutation were AL treated samples and 21% were DP treated samples. The K65 wild-type allele was detected in three recrudescent infections (100%) identified from the AL treated samples. The K65 wild-type allele was detected in two recrudescent DP treated samples (67%) while the K65Q mutant allele was identified in one DP treated (33%) recrudescent sample. Conclusions: The data demonstrate a higher frequency of the K65 resistance marker in patients with recurrent infection during the study period. The study underscores the need for consistent monitoring of molecular markers of resistance in regions of high malaria transmission. [ABSTRACT FROM AUTHOR]

Background: In Nigeria, declining responsiveness to artemether–lumefantrine (AL), the artemisinin-based combination therapy (ACT) of choice since 2005, has been reported. Pyronaridine–artesunate (PA) is a newer fixed-dose ACT recently prequalified by the WHO for the treatment of uncomplicated falciparum malaria. However, PA data from the Nigerian pediatric population is scarce. Therefore, the efficacy and safety of PA and AL using the WHO 28-day anti-malarial therapeutic efficacy study protocol in Ibadan, southwest Nigeria, were compared. Methods: In an open-labelled, randomized, controlled clinical trial, 172 children aged 3–144 months with a history of fever and microscopically confirmed uncomplicated Plasmodium falciparum malaria were enrolled in southwest Nigeria. Enrollees were randomly assigned to receive PA or AL at standard dosages according to body weight for 3 days. Venous blood was obtained for hematology, blood chemistry, and liver function tests on days 0, 3, 7, and 28 as part of the safety evaluation. Results: 165 (95.9%) of the enrolled individuals completed the study. About half (52.3%; 90/172) of enrollees were male. Eighty-seven (50.6%) received AL, while 85 (49.4%) received PA. Day 28, adequate clinical and parasitological response for PA was 92.7% [(76/82) 95% CI 83.1, 95.9] and 71.1% [(59/83) 95% CI 60.4, 79.9] for AL (0.001). Fever and parasite clearance were similar in both groups. Two of six and eight of 24 parasite recurrences were observed among PA- and AL-treated children, respectively. PCR-corrected Day-28 cure rates for PA were 97.4% (76/78) and 88.1% (59/67) for AL (= 0.04) in the per-protocol population after new infections were censored. Hematological recovery at day 28 was significantly better among PA-treated patients (34.9% 2.8) compared to those treated with AL (33.1% 3.0) (0.002). Adverse events in both treatment arms were mild and similar to the symptoms of malaria infection. Blood chemistry and liver function tests were mostly within normal limits, with an occasional marginal rise. Conclusion: PA and AL were well-tolerated. PA was significantly more efficacious than AL in both the PCR-uncorrected and PCR-corrected per-protocol populations during this study. The results of this study support the inclusion of PA in the anti-malarial treatment guidelines in Nigeria. Retrospective trial registration: Clinicaltrials.gov: NCT05192265. [ABSTRACT FROM AUTHOR]

Background: Post-artemisinin delayed hemolysis (PADH) is a serious complication in patients who recover from severe malaria after receiving artemisinin-based combined therapy (ACT), including artemether-lumefantrine. In Japan, among the antimalarial drugs recommended by the World Health Organization (WHO) guideline for severe malaria, intravenous quinine gluconate is available only in 29 designated hospitals, and intravenous artesunate is unavailable. Therefore, oral artemether-lumefantrine is occasionally administered as an alternative, even though it may be a suboptimal treatment. In non-endemic settings like Japan, a lack of knowledge of malaria and the side effects, such as post-artemisinin delayed hemolysis caused by the ACT, can have critical consequences. Like our patient, being a primigravida in the early stages of pregnancy is a serious risk factor for severe malaria and must be carefully monitored. Case presentation: This report describes a severe case of imported Plasmodium falciparum malaria complicated by fetal loss and prolonged anemia, requiring frequent blood transfusions. The patient was a previously healthy pregnant Japanese female in her 30 s. She developed a high fever 2 days after returning from Nigeria. The patient fulfilled the severe malaria criteria by WHO. On arrival, an abdominal ultrasound incidentally revealed a fetus of 5 week gestational age with a heartbeat in the uterus. Given her pregnancy and the severity of the disease, she was administered intravenous quinine 16 mg/kg as a loading dose. However, the second dose of quinine was not administered due to frequent vomiting and QTc prolongation. We initiated treatment with oral artemether-lumefantrine, and clearance of parasitemia was confirmed by microscopic observation on day 4. Miscarriage was noted on day 6 after admission. Moreover, the patient became feverish again up to 39 °C, and from days 14 to 22, the patient required multiple blood transfusions due to PADH. On day 40, follow-up was discontinued as the hemoglobin level exceeded 10 g/dL. Conclusions: In patients who recover from severe malaria after ACT treatment, monitoring the hemoglobin level for at least a month is strongly recommended for prompt identification of PADH. Travelers to malaria-endemic countries, especially primigravida women, should be provided with adequate information on the risk and prevention of infection. [ABSTRACT FROM AUTHOR]

The combinations of artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) are used as first-line treatments for uncomplicated malaria in the Ivory Coast. Different studies document the efficacy of two artemisinin-based combination therapies (ACTs) (AL and ASAQ) in the Ivory Coast. However, there is no meta-analysis examining the data set of these studies. The purpose of this work was to determine the prevalence of malaria treatment failure cases in randomized control trials with two artemisinin-based combination therapies (AL versus ASAQ) in the Ivory Coast between 2009 to 2016. This study is a meta-analysis of data from the results of four previous multicenter, open-label, randomized clinical trial studies evaluating the clinical and parasitological efficacy of artemether-lumefantrine and artesunate-amodiaquine conducted between 2009 and 2016 following World Health Organization (WHO) protocol at sentinel sites in the Ivory Coast. These drug efficacy data collected between 2009 and 2016 were analyzed. During these studies, to distinguish between recrudescence and new infection, molecular genotyping of genes encoding merozoite surface protein 1 and 2 was carried out using nested polymerase chain reaction (PCR). A total of 1575 patients enrolled in the four studies, including 768 in the AL arm and 762 in the ASAQ arm, which were fully followed either for 28 days or 42 days according to WHO protocol. The adequate clinical and parasitological response (ACPR) was higher than 95% in the two groups (intention to treat (ITT): AL = 96.59% and ASAQ = 96.81; Per Protocol (PP): AL = 99.48% and ASAQ = 99.61%) after PCR correction at day 28. Aggregate data analysis (2009–2016) showed that at day 28, the proportions of patients with recurrent infection was higher in the AL group (ITT: 3.79%, PP: 3.9%) than in the ASAQ group (ITT: 2.17%, PP: 2.23%). After PCR correction, most treatment failures were classified as new infections (AL group (ITT: 0.13%, PP: 0.13%); ASAQ group (ITT: 0.39%, PP: 0.39%). The recrudescent infections rate was high, at 0.39% compared to 0.13% for ASAQ and AL, respectively, for both ITT and PP, no significant difference. However, the Kaplan–Meier curve of cumulative treatment success showed a significant difference between the two groups after PCR from 2012–2013 (p = 0.032). Overall, ASAQ and AL have been shown to be effective drugs for the treatment of uncomplicated P. falciparum malaria in the study areas, 14 years after deployment of these drugs.

Background: In 2004, Ethiopia adopted artemether-lumefantrine (AL, Coartem®) as first-line treatment for the management of uncomplicated Plasmodium falciparum malaria. Continuous monitoring of AL therapeutic efficacy is crucial in Ethiopia, as per the World Health Organization (WHO) recommendation. This study aimed to assess the therapeutic efficacy of AL in the treatment of uncomplicated P. falciparum infection. Methods: A 28 day onearm, prospective evaluation of the clinical and parasitological response to AL was conducted at Shecha Health Centre, Arba Minch town, Southern Ethiopia. Patients were treated with six-dose regimen of AL over three days and monitored for 28 days with clinical and laboratory assessments. Participant recruitment and outcome classification was done in accordance with the 2009 WHO methods for surveillance of anti-malarial drug efficacy guidelines. Results: A total of 88 study participants were enrolled and 69 of them completed the study with adequate clinical and parasitological response. Two late parasitological failures were observed, of which one was classified as a recrudescence by polymerase chain reaction (PCR). The PCRcorrected cure rate was 98.6% (95% CI 92.3–100). AL demonstrated a rapid parasite and fever clearance with no parasitaemia on day 2 and febrile cases on day 3. Gametocyte clearance was complete by day three. No serious adverse events were reported during the 28 days follow-up. Conclusion: The study demonstrated high therapeutic efficacy and good safety profile of AL. This suggests the continuation of AL as the first-line drug for the treatment of uncomplicated P. falciparum malaria in Ethiopia. Periodic therapeutic efficacy studies and monitoring of markers of resistance are recommended for early detection of resistant parasites. [ABSTRACT FROM AUTHOR]

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The interplay of artemether-lumefantrine (AL) and atazanavir-ritonavir (ATVr) with Cytochrome P (CYP) 3A4 isoenzyme and QTc-interval may spawn clinically significant drug interactions when administered concomitantly. Cardiotoxicity and other adverse effects associated with interaction between AL and ATVr were evaluated in patients with HIV infection and malaria comorbidity. In a two-arm parallel study design, six doses of AL 80/480 mg were administered to 20 participants [control-arm (n = 10) and ATVr-arm (n = 10)], having uncomplicated Falciparum malaria, at intervals of 0, 8, 24, 36, 48 and 60 h respectively. Participants in the control arm took only AL while those in ATVr-arm took both AL and ATVr-based ART regimen. Electrocardiography, adverse events monitoring and blood tests were carried out for each of them at pre and post doses of AL. Data obtained were analyzed. QTc-interval was significantly increased in the ATVr-arm (0.4079 ± 0.008 to 0.4215 ± 0.007 s, p = 0.008) but not in the control-arm (0.4016 ± 0.018 to 0.4024 ± 0.014 s, p = 0.962). All values were, however, within normal range [0.36 – 0.44 / 0.46 s (male/female)]. General body weakness and chest pain were new adverse events reported, at post-dose of AL, in the ATVr-arm but not in the control-arm. There was no significant change (p > 0.05) in the plasma levels of creatinine, alanine aminotransferase, aspartate aminotransferase and hemoglobin at post-dose compared to pre-dose of AL in both arms of study. Concomitant administration of artemether-lumefantrine with atazanavir-ritonavir-based regimen is potentially cardiotoxic but not associated with clinically significant renal, blood nor liver toxicities. They must be used with caution.

Abstract Background Artesunate–amodiaquine (ASAQ) and Artemether–lumefantrine (AL) are the recommended treatment for uncomplicated Plasmodium falciparum malaria in Liberia. Intermittent preventive treatment with sulfadoxine/pyrimethamine is also recommended for pregnant women. The therapeutic efficacy of Artesunate–amodiaquine and Artemether–lumefantrine, and the frequency of molecular markers associated with anti-malarial drug resistance were investigated. Methods The therapeutic efficacy of ASAQ and AL was evaluated using the standard World Health Organization protocol (WHO. Methods for Surveillance of Antimalarial Drug Efficacy. Geneva: World Health Organization; 2009. https://www.who.int/malaria/publications/atoz/9789241597531/en/ ). Eligible children were recruited and monitored clinically and parasitologically for 28 days. Polymorphisms in the Pfkelch 13, chloroquine resistance transporter (Pfcrt), multidrug resistance 1 (Pfmdr-1), dihydrofolate reductase (Pfdhfr), and dihydropteroate synthase (Pfdhps) genes and copy number variations in the plasmepsin-2 (Pfpm2) gene were assessed in pretreatment samples. Results Of the 359 children enrolled, 180 were treated with ASAQ (89 in Saclepea and 91 in Bensonville) and 179 with AL (90 in Sinje and 89 in Kakata). Of the recruited children, 332 (92.5%) reached study endpoints. PCR-corrected per-protocol analysis showed ACPR of 90.2% (95% CI: 78.6–96.7%) in Bensonville and 92.7% (95% CI: 83.4.8–96.5%) in Saclepea for ASAQ, while ACPR of 100% was observed in Kakata and Sinje for AL. In both treatment groups, only two patients had parasites on day 3. No artemisinin resistance associated Pfkelch13 mutations or multiple copies of Pfpm2 were found. Most samples tested had the Pfcrt 76 T mutation (80/91, 87.9%), while the Pfmdr-1 86Y (40/91, 44%) and 184F (47/91, 51.6%) mutations were less frequent. The Pfdhfr triple mutant (51I/59R/108 N) was the predominant allele (49.2%). For the Pfdhps gene, it was the 540E mutant (16.0%), and the 436A mutant (14.3%). The quintuple allele (51I/59R/108 N-437G/540E) was detected in only one isolate (1/357). Conclusion This study reports a decline in the efficacy of ASAQ treatment, while AL remained highly effective, supporting the recent decision by NMCP to replace ASAQ with AL as first-line treatment for uncomplicated falciparum malaria. No association between the presence of the mutations in Pfcrt and Pfmdr-1 and the risk of parasite recrudescence in patients treated with ASAQ was observed. Parasites with signatures known to be associated with artemisinin and piperaquine resistance were not detected. The very low frequency of the quintuple Pfdhfr/Pfdhps mutant haplotype supports the continued use of SP for IPTp. Monitoring of efficacy and resistance markers of routinely used anti-malarials is necessary to inform malaria treatment policy. Trial registration ACTRN12617001064392.

Abstract Background The World Health Organization recommends quinine plus clindamycin as first-line treatment of malaria in the first trimester of pregnancy and as a second-line treatment for uncomplicated falciparum malaria when artemisinin-based drug combinations are not available. The efficacy of quinine plus clindamycin was compared with that of artemether-lumefantrine in the treatment of uncomplicated Plasmodium falciparum malaria in children below 5 years of age. Methods An open-label, phase 3, randomized trial was conducted in western Kenya. Children aged 6–59 months with uncomplicated falciparum malaria were randomly assigned (1:1) via a computer-generated randomization list to receive 3 days of twice a day treatment with either oral quinine (20 mg/kg/day) plus clindamycin (20 mg/kg/day) or artemether-lumefantrine (artemether 20 mg, lumefantrine 120 mg) as one (for those weighing 5–14 kg) or two (for those weighing 15–24 kg) tablets per dose. The primary outcome was a PCR-corrected rate of adequate clinical and parasitological response (ACPR) on day 28 in the per-protocol population. Results Of the 384 children enrolled, 182/192 (94.8%) receiving quinine plus clindamycin and 171/192 (89.1%) receiving artemether-lumefantrine completed the study. The PCR-corrected ACPR rate was 44.0% (80 children) in the quinine plus clindamycin group and 97.1% (166 children) in the artemether-lumefantrine group (treatment difference − 53.1%, 95% CI − 43.5% to − 62.7%). At 72 h after starting treatment, 50.3% (94 children) in the quinine plus clindamycin group were still parasitaemic compared with 0.5% (1 child) in the artemether-lumefantrine group. Three cases of severe malaria were recorded as serious adverse events in the quinine plus clindamycin group. Conclusions The study found no evidence to support the use of a 3-day low dose course of quinine plus clindamycin in the treatment of uncomplicated falciparum malaria in children under 5 years of age in Kenya, where artemether-lumefantrine is still effective. Trial Registration: This trial is registered with the Pan-African Clinical Trials Registry, PACTR20129000419241.

Abstract Background Many studies have reported high efficacy and safety of artesunate-amodiaquine (AS-AQ) and artemether-lumefantrine (AL) when administered under direct observation in Cameroon. There is paucity of data to support their continuous use in home-based treatment of uncomplicated Plasmodium falciparum malaria in Cameroon. Hence, this study aimed to assess the effectiveness and safety of AS-AQ versus AL for home-based treatment of uncomplicated P. falciparum malaria among children 6–120 months in Yaoundé, Cameroon. Methods A two-arm, open-label, randomized, controlled trial comparing the equivalence of AS-AQ (experimental group) and AL (control group) was carried out from May 2019 to April 2020 at two secondary hospitals in Yaoundé. Participants were randomized to receive either AS-AQ or AL. After the first dose, antimalarial drugs were given at home, rather than under direct observation by a study staff. The conventional on-treatment and post-treatment laboratory and clinical evaluations were not done until day 3 of the full antimalarial treatment course. The evaluation of effectiveness was mainly based on per protocol polymerase chain reaction adjusted adequate clinical and parasitological response (PP PCR adjusted ACPR) on day 28 post-treatment. Safety was based on assessment of adverse events (AEs) and severe adverse events (SAEs) from day 1 to day 28. Results A total of 242 children were randomized to receive AS-AQ (n = 114) and AL (n = 128). The PP PCR adjusted day 28 cure rates were [AS-AQ = 96.9% (95% CI, 91.2–99.4) versus AL = 95.5% (95% CI, 89.9–98.5), P = 0.797]. Expected mild to moderate adverse events were reported in both arms [AS-AQ = 83 (84.7%) versus AL = 99 (86.1%), P = 0.774]. The most common adverse events included: transient changes of hematologic indices and fever. Conclusions This study demonstrated that AS-AQ and AL are effective and safe for home management of malaria in Yaoundé. The evidence from this study supports the parallel use of the two drugs in routine practice. However, the findings from this study do not describe the likely duration of antimalarial effectiveness in holoendemic areas where multiple courses of treatment might be required. Trial registration: This study is a randomized controlled trial and it was retrospectively registered on 23/09/2020 at ClinicalTrials.gov with registration number NCT04565184.

IntroductionTo interrupt malaria transmission, strategies must target the parasite reservoir in both humans and mosquitos. Testing of community members linked to an index case, termed reactive case detection (RACD), is commonly implemented in low transmission areas, though its impact may be limited by the sensitivity of current diagnostics. Indoor residual spraying (IRS) before malaria season is a cornerstone of vector control efforts. Despite their implementation in Namibia, a country approaching elimination, these methods have been met with recent plateaus in transmission reduction. This study evaluates the effectiveness and feasibility of two new targeted strategies, reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) in Namibia.Methods and analysisThis is an open-label cluster randomised controlled trial with 2×2 factorial design. The interventions include: rfMDA (presumptive treatment with artemether-lumefantrine (AL)) versus RACD (rapid diagnostic testing and treatment using AL) and RAVC (IRS with Acellic 300CS) versus no RAVC. Factorial design also enables comparison of the combined rfMDA+RAVC intervention to RACD. Participants living in 56 enumeration areas will be randomised to one of four arms: rfMDA, rfMDA+RAVC, RACD or RACD+RAVC. These interventions, triggered by index cases detected at health facilities, will be targeted to individuals residing within 500 m of an index. The primary outcome is cumulative incidence of locally acquired malaria detected at health facilities over 1 year. Secondary outcomes include seroprevalence, infection prevalence, intervention coverage, safety, acceptability, adherence, cost and cost-effectiveness.Ethics and disseminationFindings will be reported on clinicaltrials.gov, in peer-reviewed publications and through stakeholder meetings with MoHSS and community leaders in Namibia.Trial registration numberNCT02610400; Pre-results.

ABSTRACT: Background: Plasmodium falciparum gametocytaemia has been associated with anaemia. The aim of this review was to synthesize available evidence on the comparative effect of dihydroartemisinin-piperaquine (DHA-PQ) and artemether-lumefantrine (AL) on gametocyte clearance and haemoglobin recovery in children with uncomplicated P. falciparum malaria in Africa. Methods: A systematic literature search was undertaken to identify relevant articles from online databases. The search was performed from August 2020 to 30 April 2021. Extracted data from eligible studies were pooled as risk ratios with 95% confidence intervals (CI). Results: Gametocyte carriage was reduced in both treatment groups, with no significant difference found between the groups. However, on days 28 and 42, a significant increase in serum haemoglobin level from baseline was observed in the DHA-PQ group (standardized mean difference 0.15, 95% CI 0.05–0.26; participants=2715; studies=4; I2=32%, high quality of evidence) compared with the AL group (mean difference 0.35, 95% CI 0.12–0.59; participants=1434; studies=3; I2=35%, high quality of evidence). Conclusion: DHA-PQ had a greater impact on haemoglobin recovery than AL on days 28 and 42; this difference was significant.

Abstract Background In Uganda, artemether-lumefantrine (AL) is first-line therapy and dihydroartemisinin-piperaquine (DP) second-line therapy for the treatment of uncomplicated malaria. This study evaluated the efficacy and safety of AL and DP in the management of uncomplicated falciparum malaria and measured the prevalence of molecular markers of resistance in three sentinel sites in Uganda from 2018 to 2019. Methods This was a randomized, open-label, phase IV clinical trial. Children aged 6 months to 10 years with uncomplicated falciparum malaria were randomly assigned to treatment with AL or DP and followed for 28 and 42 days, respectively. Genotyping was used to distinguish recrudescence from new infection, and a Bayesian algorithm was used to assign each treatment failure a posterior probability of recrudescence. For monitoring resistance, Pfk13 and Pfmdr1 genes were Sanger sequenced and plasmepsin-2 copy number was assessed by qPCR. Results There were no early treatment failures. The uncorrected 28-day cumulative efficacy of AL ranged from 41.2 to 71.2% and the PCR-corrected cumulative 28-day efficacy of AL ranged from 87.2 to 94.4%. The uncorrected 28-day cumulative efficacy of DP ranged from 95.8 to 97.9% and the PCR-corrected cumulative 28-day efficacy of DP ranged from 98.9 to 100%. The uncorrected 42-day efficacy of DP ranged from 73.5 to 87.4% and the PCR-corrected 42-day efficacy of DP ranged from 92.1 to 97.5%. There were no reported serious adverse events associated with any of the regimens. No resistance-associated mutations in the Pfk13 gene were found in the successfully sequenced samples. In the AL arm, the NFD haplotype (N86Y, Y184F, D1246Y) was the predominant Pfmdr1 haplotype, present in 78 of 127 (61%) and 76 of 110 (69%) of the day 0 and day of failure samples, respectively. All the day 0 samples in the DP arm had one copy of the plasmepsin-2 gene. Conclusions DP remains highly effective and safe for the treatment of uncomplicated malaria in Uganda. Recurrent infections with AL were common. In Busia and Arua, the 95% confidence interval for PCR-corrected AL efficacy fell below 90%. Further efficacy monitoring for AL, including pharmacokinetic studies, is recommended. Trial registration The trail was also registered with the ISRCTN registry with study Trial No. PACTR201811640750761

Abstract Background Ethiopia is one of the few countries in Africa where Plasmodium vivax commonly co-exists with Plasmodium falciparum, and which accounts for ~ 40% of the total number of malaria infections in the country. Regardless of the growing evidence over many decades of decreasing sensitivity of this parasite to different anti-malarial drugs, there has been no comprehensive attempt made to systematically review and meta-analyse the efficacy of different anti-malarial drugs against P. vivax in the country. However, outlining the efficacy of available anti-malarial drugs against this parasite is essential to guide recommendations for the optimal therapeutic strategy to use in clinical practice. The aim of this study was to synthesize evidence on the efficacy of anti-malarial drugs against clinical P. vivax malaria in Ethiopia. Methods All potentially relevant, peer-reviewed articles accessible in PubMed, Scopus, Web of Science, and Clinical Trial.gov electronic databases were retrieved using a search strategy combining keywords and related database-specific subject terms. Randomized controlled trials (RCTs) and non-randomized trials aiming to investigate the efficacy of anti-malarial drugs against P. vivax were included in the review. Data were analysed using Review Manager Software. Cochrane Q (χ2) and the I 2 tests were used to assess heterogeneity. The funnel plot and Egger’s test were used to examine risk of publication bias. Results Out of 1294 identified citations, 14 articles that presented data on 29 treatment options were included in the analysis. These studies enrolled 2144 clinical vivax malaria patients. The pooled estimate of in vivo efficacy of anti-malarial drugs against vivax malaria in Ethiopia was 97.91% (95% CI: 97.29–98.52%), with significant heterogeneity (I 2 = 86%, p

We described a case of Plasmodium malariae malaria in a traveler returning from the Democratic Republic of Congo to Belgium. This occurred despite successful artemether-lumefantrine treatment for Plasmodium falciparum three weeks earlier and in the absence of re-exposure in an endemic area. We discuss possible explanations for this unusual observation.

Abstract Background Artemisinin based combination therapies (ACTs) have been a cornerstone in the treatment of malaria in the world. A rapid decline in dihydroartemisinin piperaquine (DHP) and artemether lumefantrine (ALU) efficacies has been reported in some parts of South East Asia, the historical epicenter for the antimalarial drug resistance. Prolonged drug use is associated with selection of resistant parasites due to exposure to inadequate drug levels hence effects on treatment outcomes in malaria. ALU and DHP are used as first line and alternative first line, respectively, in Tanzania. This study was carried in Igombe, Tanzania to assess the efficacies of ALU and DHP in routine treatment of uncomplicated malaria among children. Methods This was a prospective study involving children up to 10 years and followed up for 28 and 35 days as per the WHO protocol, 2015 for monitoring antimalarial drug efficacy. The primary end points were crude and adjusted Adequate Clinical and Parasitological Response (ACPR), parasite clearance rate and reported adverse events. Results A total of 205 children with uncomplicated malaria were enrolled. One hundred and sixteen participants were treated with ALU, while 89 participants were treated with DHP. Two participants in the ALU group were lost within the 24 h of follow-up. The PCR unadjusted ACPR was108 (94.7%) for ALU and 88 (98.9%) for DHP, while the PCR adjusted ACPR was 109(95.6%) and 88(98.9%) for ALU and DHP, respectively, at 28 day follow-up. No treatment failure was observed in both groups. Cumulative risk of recurrent parasitemia was similar in both groups (p = 0.32). Age and parasite density were strong predictors for persistent day 1 parasitemia (p = 0.034 and 0.026, respectively). Nausea and vomiting, abdominal pain and headache were the most clinical adverse events reported in both groups of patients. Conclusion The present study shows that ALU and DHP are still efficacious after more than a decade of use with PCR corrected efficacies greater than 95% implying a failure rate less than 5% which is below the WHO minimum threshold requirement for recommendation of a change in the treatment policy. Both drugs were well tolerated with no major adverse events reported.

Abstract Background Artemisinin-based combination therapy (ACT) has been the recommended first-line treatment for uncomplicated malaria in Mozambique since 2006, with artemether–lumefantrine (AL) and amodiaquine–artesunate (AS–AQ) as the first choice. To assess efficacy of currently used ACT, an in vivo therapeutic efficacy study was conducted. Methods The study was conducted in four sentinel sites: Montepuez, Moatize, Mopeia and Massinga. Patients between 6 and 59 months old with uncomplicated Plasmodium falciparum malaria (2000–200,000 parasites/µl) were enrolled between February and September of 2018, assigned to either an AL or AS–AQ treatment arm, and monitored for 28 days. A Bayesian algorithm was applied to differentiate recrudescence from new infection using genotyping data of seven neutral microsatellites. Uncorrected and PCR-corrected efficacy results at day 28 were calculated. Results Totals of 368 and 273 patients were enrolled in the AL and AS–AQ arms, respectively. Of these, 9.5% (35/368) and 5.1% (14/273) were lost to follow-up in the AL and AS–AQ arms, respectively. There were 48 and 3 recurrent malaria infections (late clinical and late parasitological failures) in the AL and AS–AQ arms, respectively. The day 28 uncorrected efficacy was 85.6% (95% confidence interval (CI) 81.3–89.2%) for AL and 98.8% (95% CI 96.7–99.8%) for AS–AQ, whereas day 28 PCR-corrected efficacy was 97.9% (95% CI 95.6–99.2%) for AL and 99.6% (95% CI 97.9–100%) for AS–AQ. Molecular testing confirmed that 87.4% (42/48) and 33.3% (1/3) of participants with a recurrent malaria infection in the AL and AS–AQ arms were new infections; an expected finding in a high malaria transmission area. Adverse events were documented in less than 2% of participants for both drugs. Conclusion Both AL and AS–AQ have therapeutic efficacies well above the 90% WHO recommended threshold and remain well-tolerated in Mozambique. Routine monitoring of therapeutic efficacy should continue to ensure the treatments remain efficacious. Trial registration Clinicaltrials.gov: NCT04370977

Abstract Background Primaquine is a gametocytocidal drug recommended by the World Health Organization (WHO) in a single-low dose combined with artemisinin-based combination therapy (ACT) for the treatment and prevention of Plasmodium falciparum malaria transmission. Safety monitoring concerns and the lack of a universal validated and approved primaquine pharmacovigilance tool is a challenge for a national rollout in many countries. This study aimed to explore the acceptance, reliability and perceived effectiveness of the primaquine roll out monitoring pharmacovigilance tool (PROMPT). Methods This study was conducted in three dispensaries in the Coastal region of Eastern Tanzania. The study held six in-depth interviews with healthcare providers and six participatory focus group discussions with malaria patients (3) and parents/guardians of sick children (3). Participants were purposively sampled. Thematic analysis was conducted with the aid of NVivo qualitative analysis software. Results The respondents’ general acceptance and perceived effectiveness of the single-low dose primaquine and PROMPT was good. Screening procedure for treatment eligibility and explaining to patients about the possible adverse events was considered very useful for safety reasons. Crushing and dissolving of primaquine tablet to get the appropriate dose, particularly in children, was reported by all providers to be challenging. Transport costs and poor access to the health facility were the main reasons for a patient failing to return to the clinic for a scheduled follow-up visit. Treatment was perceived to be safe by both providers and patients and reported no case of a severe adverse event. Some providers were concerned with the haemoglobin drop observed on day 7. Conclusion Single-low dose primaquine was perceived to be safe and acceptable among providers and patients. PROMPT demonstrated to be a reliable and user-friendly tool among providers. Further validation of the tool by involving the National Malaria Control Programme is pivotal to addressing key challenges and facilitating primaquine adoption in the national policy.

ABSTRACT: The failure of artemisinin combination therapy (ACT) in malaria patients returning from endemic regions may be driven by parasite resistance to this treatment. ACT is used globally as the first-line treatment for Plasmodium falciparum malaria. However, artemisinin-resistant strains of P. falciparum have emerged and spread across Southeast Asia, with the risk of reaching high malaria burden regions in Africa and elsewhere. Here, we report on two malaria imported cases from Africa with possible parasite resistance to the ACT artemether-lumefantrine (AL).Case presentation: Two middle-aged males returning from Angola and Mozambique developed malaria symptoms in Portugal, where they were diagnosed and received treatment with AL as hospital inpatients. After apparent cure and discharge from hospital, these individuals returned to hospital showing signs of late clinical failure. Molecular analysis was performed across a number of drug resistance associated genes. No evidence of pfk13-mediated artemisinin resistance was found. Both subjects had complete parasite clearance after treatment with non-ACT antimalarials.Conclusion: Our case-studies highlights the need for close monitoring of signs of unsatisfactory antimalarial efficacy among AL treated patients and the possible implication of other genes or mutations in the parasite response to ACTs.