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Objective To report the prevalence of polyparasitism during pregnancy in the Lambarene region of Gabon and its association with newborn birth weight. Method Pregnant women in their third trimester were recruited in a prospective study between November 2011 and March 2015. Parasite infection status was assessed microscopically in stool, urine and blood samples. Maternal demographic and obstetrical characteristics and newborns anthropometric data were collected. Multivariable logistic regression was used to assess the association between low birth weight and polyparasitism. Results 678 of 927 pregnant women were included for analysis with mean age (SD) of 25 (6.8) years. The analysis showed that 69% (468/678) were infected with at least one parasite (Plasmodium spp., Schistosoma spp., soil-transmitted helminths, filarial infections). This comprised of 38% with monoparasitism and 31% polyparasitism. The proportion of newborn babies with a weight below 2500 g (LBW) in our study was 21% (142/678). Compared to pregnant women without infection, women with monoparasitic infection had adjusted Odds Ratio confidence interval 95% CI (aOR [95%CI]) of 1.6 [0.95-2.73], those with two parasites had aOR 95%CI of 2.63 [1.51-4.62], and those with more than two parasites had aOR of 5.08 [2.5-10.38] for delivering a newborn with low birth weight. Conclusion In Lambarene, an endemic area for multiple parasite infections, there is a high prevalence of polyparasitism in pregnant women. Polyparasitism is associated with low birth weight. Therefore, there is an urgent need for active screening and treatment of parasite infections in pregnant women to assess the potential public health benefit of such interventions.

Objectives Eravacycline is a novel synthetic halogenated tetracycline derivative with a broad antibacterial spectrum. Antibiotics, including tetracyclines, have been used for prophylaxis and, more rarely, for the treatment of malaria for several decades. The rise in drug-resistant malaria parasites renders the search for new treatment candidates urgent. We determined the in vitro potency of eravacycline against Plasmodium falciparum and investigated the apicoplast as a potential drug target. Methods Four tetracyclines, including eravacycline, tetracycline, tigecycline, and doxycycline, and the lincosamide clindamycin, were tested in 3-day and 6-day in vitro susceptibility assays of P. falciparum laboratory strain 3D7 and/or of clinical isolates obtained from 33 P. falciparum infected individuals from Gabon in 2018. Assays with isopentenyl pyrophosphate substitution were performed to investigate whether apicoplast-encoded isoprenoid biosynthesis is inhibited by these antibiotics. Results Eravacycline showed the highest activity of all tetracyclines tested in clinical isolates in the 3-day and 6-day assays. Substitution of isopentenyl pyrophosphate in vitro using the laboratory strain 3D7 reversed the activity of eravacycline and comparator antibiotics, indicating the apicoplast to be the main target organelle. Conclusions These results demonstrate the potential of novel antibiotics, and eravacycline, as candidate antimalarial therapies.

SummaryMedical research in sub-Saharan Africa is of high priority for societies to respond adequately to local health needs. Often enough it remains a challenge to build up capacity in infrastructure and human resources to highest international standards and to sustain this over mid-term to long-term periods due to difficulties in obtaining long-term institutional core funding, attracting highly qualified scientists for medical research and coping with ever changing structural and political environments. The Centre de Recherches Médicales de Lambaréné (CERMEL) serves as model for how to overcome such challenges and to continuously increase its impact on medical care in Central Africa and beyond. Starting off as a research annex to the Albert Schweitzer Hospital in Lambaréné, Gabon, it has since then expanded its activities to academic and regulatory clinical trials for drugs, vaccines and diagnostics in the field of malaria, tuberculosis, and a wide range of poverty related and neglected tropical infectious diseases. Advancing bioethics in medical research in Africa and steadily improving its global networks and infrastructures, CERMEL serves as a reference centre for several international consortia. In close collaboration with national authorities, CERMEL has become one of the main training hubs for medical research in Central Africa. It is hoped that CERMEL and its leitmotiv “to improve medical care for local populations” will serve as an inspiration to other institutions in sub-Saharan Africa to further increase African capacity to advance medicine.

Schistosomiasis is a parasitic infection highly prevalent in Central Africa where it is co-endemic with many other parasitic infections, including soil-transmitted helminths (STHs). For its optimal control, there is a need of descriptive epidemiological data for each endemic region. The objective of the present study was to determine the epidemiological situation around schistosomiasis in Lambaréné, Gabon. A cross-sectional study was conducted among schoolchildren. One urine sample per day was collected on three consecutive days for the diagnosis of schistosomiasis using a urine filtration technique. One stool sample was collected for the detection of Schistosoma spp. and STH spp. eggs using the Kato-Katz technique, and for larvae, using the coproculture technique. A total of 614 schoolchildren were included in the analysis. The overall prevalence of schistosomiasis and STH infections was 26% (159/614) and 15% (70/473), respectively. Human-freshwater contact was the main risk factor for schistosomiasis in the area (relative risk (RR) = 2.96 [2.20-4.00], P < 0.001). Hematuria (RR = 5.53 [4.30-7.10], P < 0.001) and proteinuria (RR = 2.12 [1.63-2.75], P < 0.001) as well as infection with Trichuris trichiura (RR = 1.86 [1.33-2.61], P = 0.002) and Ascaris lumbricoides (RR = 1.96 [1.19-3.21], P = 0.039) were associated with an increased risk of schistosomiasis. Trichuris trichiura was the highest prevalent STH species in the area. Our study reports a moderate prevalence for schistosomiasis with human-water contact as the main risk factor, whereas the prevalence of STH infections appears to be low. Our results stress the need for the implementation of WHO recommendations for schistosomiasis control.

Background Fetal growth restriction is a major complication of pregnancy and is associated with stillbirth, infant death and child morbidity. Ultrasound monitoring of pregnancy is becoming more common in Africa for fetal growth monitoring in clinical care and research, but many countries have no national growth charts. We evaluated the new international fetal growth standards from INTERGROWTH-21st and WHO in a cohort from southern Benin. Methods Repeated ultrasound and clinical data were collected in women from the preconceptional RECIPAL cohort (241 women with singleton pregnancies, 964 ultrasounds). We modelled fetal biometric parameters including abdominal circumference (AC) and estimated fetal weight (EFW) and compared centiles to INTERGROWTH-21st and WHO standards, using the Bland and Altman method to assess agreement. For EFW, we used INTERGROWTH-21st standards based on their EFW formula (IG21st) as well as a recent update using Hadlock’s EFW formula (IG21hl). Proportions of fetuses with measurements under the 10th percentile were compared. Results Maternal malaria and anaemia prevalence was 43% and 69% respectively and 11% of women were primigravid. Overall, the centiles in the RECIPAL cohort were higher than that of INTERGROWTH-21st and closer to that of WHO. Consequently, the proportion of fetuses under 10th percentile thresholds was systematically lower when applying IG21st compared to WHO standards. At 27–31 weeks and 33–38 weeks, respectively, 7.4% and 5.6% of fetuses had EFW th percentile using IG21hl standards versus 10.7% and 11.6% using WHO standards. Conclusion Despite high anemia and malaria prevalence in the cohort, IG21st and WHO standards did not identify higher than expected proportions of fetuses under the 10th percentiles of ultrasound parameters or EFW. The proportions of fetuses under the 10th percentile threshold for IG21st charts were particularly low, raising questions about its use to identify growth-restricted fetuses in Africa.

IntroductionMalaria infection during pregnancy is an important driver of maternal and neonatal health especially among HIV-infected women. Intermittent preventive treatment in pregnancy (IPTp) with sulphadoxine–pyrimethamine is recommended for malaria prevention in HIV-uninfected women, but it is contraindicated in those HIV-infected on cotrimoxazole prophylaxis (CTXp) due to potential adverse effects. Dihydroartemisinin–piperaquine (DHA–PPQ) has been shown to improve antimalarial protection, constituting a promising IPTp candidate. This trial’s objective is to determine if monthly 3-day IPTp courses of DHA–PPQ added to daily CTXp are safe and superior to CTXp alone in decreasing the proportion of peripheral malaria parasitaemia at the end of pregnancy.Methods and analysisThis is a multicentre, two-arm, placebo-controlled, individually randomised trial in HIV-infected pregnant women receiving CTXp and antiretroviral treatment. A total of 664 women will be enrolled at the first antenatal care clinic visit in sites from Gabon and Mozambique. Participants will receive an insecticide-treated net, and they will be administered monthly IPTp with DHA-PPQ or placebo (1:1 ratio) as directly observed therapy from the second trimester of pregnancy. Primary study outcome is the prevalence of maternal parasitaemia at delivery. Secondary outcomes include prevalence of malaria-related maternal and infant outcomes and proportion of adverse perinatal outcomes. Participants will be followed until 6 weeks after the end of pregnancy and their infants until 1 year of age to also evaluate the impact of DHA–PPQ on mother-to-child transmission of HIV. The analysis will be done in the intention to treat and according to protocol cohorts, adjusted by gravidity, country, seasonality and other variables associated with malaria.Ethics and disseminationThe protocol was reviewed and approved by the institutional and national ethics committees of Gabon and Mozambique and the Hospital Clinic of Barcelona. Project results will be presented to all stakeholders and published in open-access journals.Trial registration numberNCT03671109.

Pregnant women constitute a promising sentinel group for continuous monitoring of malaria transmission. To identify antibody signatures of recent Plasmodium falciparum exposure during pregnancy, we dissected IgG responses against VAR2CSA, the parasite antigen that mediates placental sequestration. We used a multiplex peptide-based suspension array in 2,354 samples from pregnant women from Mozambique, Benin, Kenya, Gabon, Tanzania, and Spain. Two VAR2CSA peptides of limited polymorphism were immunogenic and targeted by IgG responses readily boosted during infection and with estimated half-lives of

Background Schistosomiasis is highly prevalent in Africa. Praziquantel is effective against adult schistosomes but leaves prepatent stages unaffected—which is a limit to patient management and elimination. Given the large-scale use of praziquantel, development of drug resistance by Schistosoma is feared. Antimalarials are promising drugs for alternative treatment strategies of Schistosoma infections. Development of drugs with activity against both malaria and schistosomiasis is particularly appealing as schistosome infections often occur concomitantly with malaria parasites in sub-Saharan Africa. Therefore, antiplasmodial compounds were progressively tested against Schistosoma in vitro, in mice, and in a clinical study. Results Amongst 16 drugs and 1 control tested, pyronaridine, methylene blue and 5 other antimalarials were highly active in vitro against larval stage schistosomula with a 50% inhibitory concentration below 10 μM. Both drugs were lethal to ex vivo adult worms tested at 30 μM with methylene blue also active at 10 μM. Pyronaridine treatment of mice infected with S. mansoni at the prepatent stage reduced worm burden by 82% and cured 7 out of 12 animals, however in mice adult stages remained viable. In contrast, methylene blue inhibited adult worms by 60% but cure was not achieved. In an observational pilot trial in Gabon in children, the antimalarial drug combination pyronaridine-artesunate (Pyramax) reduced S. haematobium egg excretion from 10/10 ml urine to 0/10 ml urine, and 3 out of 4 children were cured. Conclusion Pyronaridine and methylene blue warrant further investigation as candidates for schistosomiasis treatment. Both compounds are approved for human use and evidence for their potential as antischistosomal compounds can be obtained directly from clinical testing. Particularly, pyronaridine-artesunate, already available as an antimalarial drug, calls for further clinical evaluation. Trial registration ClinicalTrials.gov Identifier NCT03201770., Author summary Praziquantel is still the only drug in use for the treatment of all Schistosoma spp. and is exclusively active against the adult life cycle stage, since schistosomes in the prepatent period of up to eight weeks are not affected by the drug. Although resistance to praziquantel has not been confirmed and its existence remains controversial, some countries have identified clinical schistosome isolates with reduced sensitivity to praziquantel, after deployment in mass drug administration programs. The need for a new antischistosomal compound is urgent, ideally exhibiting broad activity against all stages of the parasite’s life cycle present in humans. After testing a series of antiplasmodial compounds, the authors found that several compounds also exhibited antischistosomal activity at various life cycle stages of the worms, including pyronaridine and methylene blue, both compounds already approved for human use. A pilot trial with pyronaridine-artesunate done in Gabon showed the first promising results against Schistosoma infections.

Background In Phase II/III randomized controlled clinical trials for the treatment of acute uncomplicated malaria, pyronaridine–artesunate demonstrated high efficacy and a safety profile consistent with that of comparators, except that asymptomatic, mainly mild-to-moderate transient increases in liver aminotransferases were reported for some patients. Hepatic safety, tolerability, and effectiveness have not been previously assessed under real-world conditions in Africa. Methods and findings This single-arm, open-label, cohort event monitoring study was conducted at 6 health centers in Cameroon, Democratic Republic of Congo, Gabon, Ivory Coast, and Republic of Congo between June 2017 and April 2019. The trial protocol as closely as possible resembled real-world clinical practice for the treatment of malaria at the centers. Eligible patients were adults or children of either sex, weighing at least 5 kg, with acute uncomplicated malaria who did not have contraindications for pyronaridine–artesunate treatment as per the summary of product characteristics. Patients received fixed-dose pyronaridine–artesunate once daily for 3 days, dosed by body weight, without regard to food intake. A tablet formulation was used in adults and adolescents and a pediatric granule formulation in children and infants under 20 kg body weight. The primary outcome was the hepatic event incidence, defined as the appearance of the clinical signs and symptoms of hepatotoxicity confirmed by a >2× rise in alanine aminotransferase/aspartate aminotransferase (ALT/AST) versus baseline in patients with baseline ALT/AST >2× the upper limit of normal (ULN). As a secondary outcome, this was assessed in patients with ALT/AST >2× ULN prior to treatment versus a matched cohort of patients with normal baseline ALT/AST. The safety population comprised 7,154 patients, of mean age 13.9 years (standard deviation (SD) 14.6), around half of whom were male (3,569 [49.9%]). Patients experienced 8,560 malaria episodes; 158 occurred in patients with baseline ALT/AST elevations >2×ULN. No protocol-defined hepatic events occurred following pyronaridine–artesunate treatment of malaria patients with or without baseline hepatic dysfunction. Thus, no cohort comparison could be undertaken. Also, as postbaseline clinical chemistry was only performed where clinically indicated, postbaseline ALT/AST levels were not systematically assessed for all patients. Adverse events of any cause occurred in 20.8% (1,490/7,154) of patients, most frequently pyrexia (5.1% [366/7,154]) and vomiting (4.2% [303/7,154]). Adjusting for Plasmodium falciparum reinfection, clinical effectiveness at day 28 was 98.6% ([7,369/7,746] 95% confidence interval (CI) 98.3 to 98.9) in the per-protocol population. There was no indication that comorbidities or malnutrition adversely affected outcomes. The key study limitation was that postbaseline clinical biochemistry was only evaluated when clinically indicated. Conclusions Pyronaridine–artesunate had good tolerability and effectiveness in a representative African population under conditions similar to everyday clinical practice. These findings support pyronaridine–artesunate as an operationally useful addition to the management of acute uncomplicated malaria. Trial registration ClinicalTrials.gov NCT03201770., Gaston Tona Lutete and co-workers report on safety and effectiveness of the antimalarial drug pyronaridine-artesunate in African countries., Author summary Why was this study done? Pyronaridine–artesunate has shown high efficacy and an acceptable safety profile in randomized controlled clinical trials for the treatment of acute uncomplicated Plasmodium falciparum malaria. Transient, asymptomatic, mostly mild-to-moderate increases in liver aminotransferases have been observed with pyronaridine–artesunate in some patients. We assessed pyronaridine–artesunate hepatic safety, tolerability, and effectiveness in adults and children for the treatment of acute uncomplicated malaria under real-world conditions in Africa, including patients with elevated baseline liver aminotransferases. What did the researchers do and find? In a single-arm, open-label, cohort event monitoring study conducted across 5 African countries, patients of any age, weighing >5 kg with acute uncomplicated malaria received fixed-dose pyronaridine–artesunate once daily for 3 days. Patient exclusion and inclusion criteria were consistent with the approved prescribing information, and patients with elevated baseline liver enzymes could be treated under the protocol. The study included 8,560 malaria episodes, 158 of which occurred in patients with baseline alanine aminotransferase (ALT) or aspartate aminotransferase (AST) abnormalities. There were no hepatic events following pyronaridine–artesunate treatment. Tolerability was as reported in previous studies, and treatment effectiveness at day 28 was 98.6% in patients with acute uncomplicated P. falciparum malaria. What do these findings mean? Pyronaridine–artesunate was an operationally effective and well-tolerated antimalarial therapy in this unselected population of patients from 5 African countries.

Background For uncomplicated Plasmodium falciparum malaria, highly efficacious single-dose treatments are expected to increase compliance and improve treatment outcomes, and thereby may slow the development of resistance. The efficacy and safety of a single-dose combination of artefenomel (800 mg) plus ferroquine (400/600/900/1200 mg doses) for the treatment of uncomplicated P. falciparum malaria were evaluated in Africa (focusing on children ≤ 5 years) and Asia. Methods The study was a randomized, double-blind, single-dose, multi-arm clinical trial in patients aged > 6 months to kelch-13 mutations were explored. Results A total of 373 patients were treated: 289 African patients ≤ 5 years (77.5%), 64 African patients > 5 years and 20 Asian patients. None of the treatment arms met the target efficacy criterion for PCR-adjusted ACPR at Day 28 (lower limit of 95% confidence interval [CI] > 90%). PCR-adjusted ACPR at Day 28 [95% CI] in the PP Set ranged from 78.4% [64.7; 88.7%] to 91.7% [81.6; 97.2%] for the 400 mg to 1200 mg ferroquine dose. Efficacy rates were low in Vietnamese patients, ranging from 20 to 40%. A clear relationship was found between drug exposure (artefenomel and ferroquine concentrations at Day 7) and efficacy (primary endpoint), with higher concentrations of both drugs resulting in higher efficacy. Six distinct kelch-13 mutations were detected in parasite isolates from 10/272 African patients (with 2 mutations known to be associated with artemisinin resistance) and 18/20 Asian patients (all C580Y mutation). Vomiting within 6 h of initial artefenomel administration was common (24.6%) and associated with lower drug exposures. Conclusion The efficacy of artefenomel/ferroquine combination was suboptimal in African children aged ≤ 5 years, the population of interest, and vomiting most likely had a negative impact on efficacy. Trial registration ClinicalTrials.gov, NCT02497612. Registered 14 Jul 2015, https://clinicaltrials.gov/ct2/show/NCT02497612?term=NCT02497612&draw=2&rank=1

Background Helminths can modulate the host immune response to Plasmodium falciparum and can therefore affect the risk of clinical malaria. We assessed here the effect of helminth infections on both the immunogenicity and efficacy of the GMZ2 malaria vaccine candidate, a recombinant protein consisting of conserved domains of GLURP and MSP3, two asexual blood-stage antigens of P. falciparum. Controlled human malaria infection (CHMI) was used to assess the efficacy of the vaccine. Methodology In a randomized, double-blind Phase I clinical trial, fifty, healthy, lifelong malaria-exposed adult volunteers received three doses of GMZ2 adjuvanted with either Cationic Adjuvant Formulation (CAF) 01 or Alhydrogel, or a control vaccine (Rabies) on days (D) 0, D28 and D56, followed by direct venous inoculation (DVI) of 3,200 P. falciparum sporozoites (PfSPZ Challenge) approximately 13 weeks after last vaccination to assess vaccine efficacy. Participants were followed-up on a daily basis with clinical examinations and thick blood smears to monitor P. falciparum parasitemia for 35 days. Malaria was defined as the presence of P. falciparum parasites in the blood associated with at least one symptom that can be associated to malaria over 35 days following DVI of PfSPZ Challenge. Soil-transmitted helminth (STH) infection was assessed by microscopy and by polymerase chain reaction (PCR) on stool, and Schistosoma infection was assessed by microscopy on urine. Participants were considered as infected if positive for any helminth either by PCR and/or microscopy at D0 and/or at D84 (Helm+) and were classified as mono-infection or co-infection. Total vaccine-specific IgG concentrations assessed on D84 were analysed as immunogenicity outcome. Main findings The helminth in mono-infection, particularly Schistosoma haematobium and STH were significantly associated with earlier malaria episodes following CHMI, while no association was found in case of coinfection. In further analyses, the anti-GMZ2 IgG concentration on D84 was significantly higher in the S. haematobium-infected and significantly lower in the Strongyloides stercoralis-infected groups, compared to helminth-negative volunteers. Interesting, in the absence of helminth infection, a high anti-GMZ2 IgG concentration on D84 was significantly associated with protection against malaria. Conclusions Our results suggest that helminth infection may reduce naturally acquired and vaccine-induced protection against malaria. Vaccine-specific antibody concentrations on D84 may be associated with protection in participants with no helminth infection. These results suggest that helminth infection affect malaria vaccine immunogenicity and efficacy in helminth endemic countries., Author summary Helminths, mainly because of their immune regulatory effects, are able to impact the response induced by vaccines. In the context of clinical trial designs that measure accrual of natural infections during follow up or outcome of controlled human malaria infection (CHMI), their effect on vaccine efficacy can be measured. Indeed, most of such clinical trials on malaria vaccine candidates conducted in Africa, especially where the prevalence of helminths is high, have shown a certain limit in their efficacy and immunogenicity, as compared to results observed in European and U.S volunteers. The present analysis assessed the effect of helminths on GMZ2, a malaria vaccine candidate. We found a high level of anti-GMZ2 antibodies among volunteers not infected with helminths and protected against CHMI, indicating efficacy of the candidate vaccine in this population. We found a species-dependent effect of helminths on the level of post-immunization GMZ2-specific IgG concentration, and an association of helminths with an early onset of malaria in CHMI. Our findings reveal that helminths are associated with immunogenicity and may decrease the protective effect of antibodies induced by vaccination. Helminth infection status shall be determined when measuring the immunogenicity and efficacy of malaria vaccine candidates in helminth endemic countries.

Fosmidomycin–piperaquine is being developed as nonartemisinin-based combination therapy to meet the challenge of emerging artemisinin resistance. The combination appeared to have high efficacy and be safe and well tolerated despite observed transient changes in electrocardiogram with prolongation of the QT interval., Background Fosmidomycin–piperaquine is being developed as nonartemisinin-based combination therapy to meet the challenge of emerging artemisinin resistance. Methods The study was a phase 2, single-arm, proof-of-concept study of the efficacy, tolerability, and safety of fosmidomycin–piperaquine for the treatment of uncomplicated Plasmodium falciparum monoinfection in Gabon. Adults and children of both sexes with initial parasite counts between 1000 and 150000/µL received oral treatment with fosmidomycin (twice daily doses of 30 mg/kg) and piperaquine (once daily dose of 16 mg/kg) for 3 days and followed-up for 63 days. The primary efficacy endpoint was the per-protocol polymerase chain reaction (PCR)–corrected day 28 adequate clinical and parasitological response (ACPR). Results One hundred patients were enrolled. The PCR-corrected day 28 ACPR rate was 83/83, or 100% (95% confidence interval, 96–100). Fourteen patients had asexual parasitaemia between day 28 and day 63; all were typed by PCR as new infections. Fosmidomycin–piperaquine therapy led to rapid parasite clearance (median, 36 hours; interquartile range [IQR], 6–60) and fever clearance time (median, 12 hours; IQR, 6–48). The electrocardiogram assessments showed 2 patients with prolonged QT interval >500 msec following study drug administration. The majority of adverse events affected the gastrointestinal and respiratory tracts and were transient and mild to moderate in severity. Conclusions This is the first report of the use of the combination fosmidomycin–piperaquine. The combination appeared to have high efficacy and be safe and well tolerated despite observed transient changes in electrocardiogram with prolongation of the QT interval. Clinical Trials Registration. NCT02198807.

Background Resistance and tolerance to Plasmodium falciparum can determine the progression of malaria disease. However, quantitative evidence of tolerance is still limited. We investigated variations in the adverse impact of P. falciparum infections among African pregnant women under different intensities of malaria transmission. Methods P. falciparum at delivery was assessed by microscopy, quantitative PCR (qPCR) and placental histology in 946 HIV-uninfected and 768 HIV-infected pregnant women from Benin, Gabon, Kenya and Mozambique. Resistance was defined by the proportion of submicroscopic infections and the levels of anti-parasite antibodies quantified by Luminex, and tolerance by the relationship of pregnancy outcomes with parasite densities at delivery. Results P. falciparum prevalence by qPCR in peripheral and/or placental blood of HIV-uninfected Mozambican, Gabonese and Beninese women at delivery was 6% (21/340), 11% (28/257) and 41% (143/349), respectively. The proportion of peripheral submicroscopic infections was higher in Benin (83%) than in Mozambique (60%) and Gabon (55%; P = 0.033). Past or chronic placental P. falciparum infection was associated with an increased risk of preterm birth in Mozambican newborns (OR = 7.05, 95% CI 1.79 to 27.82). Microscopic infections were associated with reductions in haemoglobin levels at delivery among Mozambican women (–1.17 g/dL, 95% CI –2.09 to –0.24) as well as with larger drops in haemoglobin levels from recruitment to delivery in Mozambican (–1.66 g/dL, 95% CI –2.68 to –0.64) and Gabonese (–0.91 g/dL, 95% CI –1.79 to –0.02) women. Doubling qPCR-peripheral parasite densities in Mozambican women were associated with decreases in haemoglobin levels at delivery (–0.16 g/dL, 95% CI –0.29 to –0.02) and increases in the drop of haemoglobin levels (–0.29 g/dL, 95% CI –0.44 to –0.14). Beninese women had higher anti-parasite IgGs than Mozambican women (P

Background The majority of Plasmodium falciparum malaria cases in Africa are treated with the artemisinin combination therapies artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ), with amodiaquine being also widely used as part of seasonal malaria chemoprevention programs combined with sulfadoxine-pyrimethamine. While artemisinin derivatives have a short half-life, lumefantrine and amodiaquine may give rise to differing durations of post-treatment prophylaxis, an important additional benefit to patients in higher transmission areas. Methods We analyzed individual patient data from 8 clinical trials of AL versus AS-AQ in 12 sites in Africa (n = 4214 individuals). The time to PCR-confirmed reinfection after treatment was used to estimate the duration of post-treatment protection, accounting for variation in transmission intensity between settings using hidden semi-Markov models. Accelerated failure-time models were used to identify potential effects of covariates on the time to reinfection. The estimated duration of chemoprophylaxis was then used in a mathematical model of malaria transmission to determine the potential public health impact of each drug when used for first-line treatment. Results We estimated a mean duration of post-treatment protection of 13.0 days (95% CI 10.7–15.7) for AL and 15.2 days (95% CI 12.8–18.4) for AS-AQ overall. However, the duration varied significantly between trial sites, from 8.7–18.6 days for AL and 10.2–18.7 days for AS-AQ. Significant predictors of time to reinfection in multivariable models were transmission intensity, age, drug, and parasite genotype. Where wild type pfmdr1 and pfcrt parasite genotypes predominated ( 80%), AL provided up to 1.5-fold longer protection than AS-AQ. Our simulations found that these differences in the duration of protection could alter population-level clinical incidence of malaria by up to 14% in under-5-year-old children when the drugs were used as first-line treatments in areas with high, seasonal transmission. Conclusion Choosing a first-line treatment which provides optimal post-treatment prophylaxis given the local prevalence of resistance-associated markers could make a significant contribution to reducing malaria morbidity.

Summary Background Loiasis is a highly prevalent helminth infection found in distinct regions of sub-Saharan Africa. The disease has been considered to be of minor clinical significance, but this belief is being increasingly challenged by recent evidence. We aimed to prospectively quantify the overall burden of disease caused by loiasis in an endemic region of Gabon, using disability-adjusted life years (DALYs). Methods We did a cross-sectional survey during 2017 and 2018 in rural Gabon. Volunteers underwent diagnostic tests for loiasis and were given a standardised questionnaire on symptoms. Participants reporting eye worm migration or harbouring Loa loa microfilariae were defined as loiasis positive. Morbidity-based DALYs associated with loiasis were estimated for the rural population of Gabon. Findings Between Sept 1, 2017 and May 31, 2018, 1235 participants residing in 38 villages in the Gabonese departments of Tsamba-Magotsi and Ogooue et des Lacs were screened. 626 (50·8%) of 1232 eligible participants had loiasis. 520 (42·2%) of 1232 participants reported eye worm migration. 478 (93·9%) of 509 individuals with eye worm migration also reported associated pain, and 397 (78·6%) of 505 reported vision disturbances. After correcting for age and sex, loiasis was significantly associated with a variety of symptoms, including transient painful oedema (adjusted odds ratio 1·76 [95% CI 1·37–2·26]) and arthralgia (1·30 [1·01–1·69]). Application of attributable fractions of correlating symptoms resulted in 412·9 (95% CI 273·9–567·7) morbidity-based DALYs per 100 000 people in rural Gabon. Interpretation Loiasis, with the pathognomonic sign of eye worm migration, appears to not be benign, but severely impeding to affected individuals. Furthermore, loiasis is associated with substantial morbidity, comparable to that of other neglected tropical parasitic diseases. These findings call for reconsideration of L loa as a relevant pathogen in affected populations, with a need for more concerted research and control of these infections. Funding Federal Ministry of Science, Research and Economy of Austria, and the European Union.

Background Malaria remains a major public health problem, affecting mainly low-and middle-income countries. The management of this parasitic disease is challenged by ever increasing drug resistance. This study, investigated the therapeutic efficacy, tolerability and safety of artemether–lumefantrine (AL) and artesunate–amodiaquine (AS–AQ), used as first-line drugs to treat uncomplicated malaria in Lambaréné, Gabon. Methods A non-randomized clinical trial was conducted between October 2017 and March 2018 to assess safety, clinical and parasitological efficacy of fixed-doses of AL and AS–AQ administered to treat uncomplicated Plasmodium falciparum malaria in children aged from 6 months to 12 years. After 50 children were treated with AL, another 50 children received ASAQ. The 2009 World Health Organization protocol for monitoring of the efficacy of anti‑malarial drugs was followed. Molecular markers msp1 and msp2 were used to differentiate recrudescence and reinfection. For the investigation of artemisinin resistant markers, gene mutations in Pfk13 were screened. Results Per-protocol analysis on day 28 showed a PCR corrected cure rate of 97% (95% CI 86–100) and 95% (95% CI 84–99) for AL and AS–AQ, respectively. The most frequent adverse event in both groups was asthenia. No mutations in the kelch-13 gene associated with artemisinin resistance were identified. All participants had completed microscopic parasite clearance by day 3 post-treatment. Conclusion This study showed that AL and AS–AQ remain efficacious, well-tolerated, and are safe to treat uncomplicated malaria in children from Lambaréné. However, a regular monitoring of efficacy and a study of molecular markers of drug resistance to artemisinin in field isolates is essential. Trial registration ANZCTR, ACTRN12616001600437. Registered 18 November, http://www.anzctr.org.au/TrialSearch.aspx?searchTxt=ACTRN12616001600437p&isBasic=True

Microscopy and rapid diagnostic tests (RDTs) are the main diagnostic tools for malaria but fail to detect low-density parasitemias that are important for maintaining malaria transmission. To complement existing diagnostic methods, an isothermal reverse transcription-recombinase polymerase amplification and lateral flow assay (RT-RPA) was developed. We compared the performance with that of ultrasensitive reverse transcription-quantitative PCR (uRT-qPCR) using nucleic acid extracts from blood samples (n = 114) obtained after standardized controlled human malaria infection (CHMI) with Plasmodium falciparum sporozoites. As a preliminary investigation, we also sampled asymptomatic individuals (n = 28) in an area of malaria endemicity (Lambarene, Gabon) to validate RT-RPA and assess its performance with unprocessed blood samples (dbRT-RPA). In 114 samples analyzed from CHMI trials, the positive percent agreement to uRT-qPCR was 90% (95% confidence interval [CI], 80 to 96). The negative percent agreement was 100% (95% CI, 92 to 100). The lower limit of detection was 64 parasites/ml. In Gabon, RT-RPA was 100% accurate with asymptomatic volunteers (n = 28), while simplified dbRT-RPA showed 89% accuracy. In a subgroup analysis, RT-RPA detected 9/10 RT-qPCR-positive samples, while loop-mediated isothermal amplification (LAMP) detected 2/10. RT-RPA is a reliable diagnostic test for asymptomatic low-density infections. It is particularly useful in settings where uRT-qPCR is difficult to implement.

Background Innovative approaches are needed to limit antimalarial resistance evolution. Understanding the role of intermittent preventive treatment in pregnancy (IPTp) on the selection for resistance and the impact such selection has on pregnancy outcomes can guide future interventions. Methods Plasmodium falciparum isolates (n = 914) from 2 randomized clinical trials were screened for pfmdr1 copy number variation and pfcrt, pfmdr1, pfdhfr, and pfdhps resistance markers. The trials were conducted between 2010 and 2013 in Benin, Gabon, Kenya, and Mozambique to establish the efficacy of IPTp-mefloquine (MQ) compared with IPTp-sulphadoxine-pyrimethamine (SP) in human immunodeficiency virus (HIV)-uninfected and to IPTp-placebo in HIV-infected women. Results In HIV-uninfected women, the prevalence of pfcrt mutants, pfdhfr/pfdhps quintuple mutants, and pfmdr1 copy number was similar between women receiving IPT-SP and IPTp-MQ. However, prevalence of pfmdr1 polymorphism 86Y was lower in the IPTp-MQ group than in the IPTp-SP group, and within the IPTp-MQ group it was lower at delivery compared with recruitment. No effect of IPTp-MQ on resistance markers was observed among HIV-infected women. The carriage of resistance markers was not associated with pregnancy outcomes. Conclusions Selection of wild-type pfmdr1 polymorphism N86 by IPTp-MQ highlights the strong selective pressure IPTp can exert and the opportunity for using negative cross-resistance in drug choice for clinical treatment and IPTp.

Artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ) are the most commonly-used treatments against Plasmodium falciparum malaria in Africa. The lumefantrine and amodiaquine partner drugs may provide differing durations of post-treatment prophylaxis, an important additional benefit to patients. Analyzing 4214 individuals from clinical trials in 12 sites, we estimated a mean duration of post-treatment protection of 13.0 days (95% CI 10.7-15.7) for AL and 15.2 days (95% CI 12.8-18.4) for AS-AQ after allowing for transmission intensity. However, the duration varied substantially between sites: where wild type pfmdr1 86 and pfcrt 76 parasite genotypes predominated, AS-AQ provided ∼2-fold longer protection than AL. Conversely, AL provided up to 1.5-fold longer protection than AS-AQ where mutants were common. We estimate that choosing AL or AS-AQ as first-line treatment according to local drug sensitivity could alter population-level clinical incidence of malaria by up to 14% in under-five year olds where malaria transmission is high.

Background Malaria remains a public health issue, particularly in sub-Saharan Africa with special features of seriousness in young children and pregnant women. Adolescents and adults are reported to have acquired a semi-immune status and, therefore, present with low parasitaemia. Children are understood to present with a much higher parasitaemia and severe malaria. It is a concern that effective malaria control programmes targeting young children may lead to a delay in the acquisition of acquired immunity and, therefore, causing a shift in the epidemiology of malaria. Prevalence and parasitaemia were explored in adolescents and adults with Plasmodium falciparum infections compared to young children in the area of Lambaréné, Gabon as an indicator for semi-immunity. Methods A cross-sectional study was conducted at the Centre de Recherches Médicales de Lambaréné (CERMEL) during a 6-month period in 2018. Symptomatic patients, of all ages were screened for malaria at health facilities in Lambaréné and Fougamou and their respective surrounding villages in the central region of Gabon. Plasmodium falciparum infections were determined either by rapid diagnostic test (RDT) or by microscopy. Descriptive analysis of data on parasite densities, anaemia, and fever are presented. Results 1589 individuals screened were included in this analysis, including 731 (46%) adolescents and adults. Out of 1377 assessed, the proportion of P. falciparum positive RDTs was high among adolescents (68%) and adults (44%), compared to young children (55%) and school children (72%). Out of 274 participants assessed for malaria by microscopy, 45 (16%) had a parasite count above 10,000/µl of which 9 (20%) were adults. Conclusion This study shows a high rate of P. falciparum infections in adolescents and adults associated with high-level parasitaemia similar to that of young children. Adolescents and adults seem to be an at-risk population, suggesting that malaria programmes should consider adolescents and adults during the implementation of malaria prevention and case management programmes with continuous care, since they also act as reservoirs for P. falciparum.

Background Today, the development of new and well-tolerated anti-malarial drugs is strongly justified by the emergence of Plasmodium falciparum resistance. In 2014–2015, a phase 2b clinical study was conducted to evaluate the efficacy of a single oral dose of Artefenomel (OZ439)–piperaquine (PPQ) in Asian and African patients presenting with uncomplicated falciparum malaria. Methods Blood samples collected before treatment offered the opportunity to investigate the proportion of multidrug resistant parasite genotypes, including P. falciparum kelch13 mutations and copy number variation of both P. falciparum plasmepsin 2 (Pfpm2) and P. falciparum multidrug resistance 1 (Pfmdr1) genes. Results Validated kelch13 resistance mutations including C580Y, I543T, P553L and V568G were only detected in parasites from Vietnamese patients. In Africa, isolates with multiple copies of the Pfmdr1 gene were shown to be more frequent than previously reported (21.1%, range from 12.4% in Burkina Faso to 27.4% in Uganda). More strikingly, high proportions of isolates with multiple copies of the Pfpm2 gene, associated with piperaquine (PPQ) resistance, were frequently observed in the African sites, especially in Burkina Faso and Uganda (> 30%). Conclusions These findings were considered to sharply contrast with the recent description of increased sensitivity to PPQ of Ugandan parasite isolates. This emphasizes the necessity to investigate in vitro susceptibility profiles to PPQ of African isolates with multiple copies of the Pfpm2 gene and estimate the risk of development of PPQ resistance in Africa. Trial registration Clinicaltrials.gov reference: NCT02083380. Study title: Phase II efficacy study of artefenomel and piperaquine in adults and children with P. falciparum malaria. https://clinicaltrials.gov/ct2/results?cond=&term=NCT02083380&cntry=&state=&city=&dist=. FSFV: 23-Jul-2014; LSLV: 09-Oct-2015

Background It is unclear whether individual treatment of scabies is similarly effective compared to household treatment. This study compared these two treatment strategies with topical benzyl benzoate for treating scabies in Lambaréné, Gabon. Methods Participants presenting with uncomplicated scabies were randomized into either the Individual Treatment group, where only the affected participants received treatment, or the Household Treatment group, where all family members were treated in parallel to the affected participants regardless of signs and symptoms. The primary endpoint was clinical cure after 28 days; the secondary endpoint was the proportion of affected household members per household after 28 days. Results After 28 days, from a total of 79 participants assessed, 67% (n = 53) were clinically cured; 59% (20/34) in the Individual Treatment group and 73% (33/45) in the Household Treatment group. Participants in the Household Treatment group had about twice the odds of being cured (odds ratio 1.9, 95% confidence interval: 0.8–4.9; p = 0.17). For the secondary outcome, an effect of similar size was observed. Conclusions Our findings show that treating close contacts of persons affected by scabies may be beneficial to patients and contacts, however, the benefit was less pronounced than anticipated and further research is needed to definitively answer this question., Author summary Scabies is a skin disease caused by parasitic mites that burrow into the skin and cause itchiness and rash. Since these mites can be easily transmitted from person to person the disease is highly contagious. Many guidelines on the treatment of scabies recommend that all family members and close contacts of persons suffering from scabies should be treated alongside the affected person, in order to prevent the disease from spreading. However, there is only little evidence to be found in the medical literature on how well this practice works. We conducted a study in Lambaréné, Gabon and surrounding villages, where many cases of scabies occurred at the time, to answer this question. We found that, on average, those patients whose entire family was treated were more likely to be cured after 4 weeks, and that fewer of their family members were affected. However, the difference to patients whose families weren’t treated was smaller than expected, suggesting that larger studies are needed to definitively answer the question.

Background Malaria burden remains high in the sub-Saharan region where helminths are prevalent and where children are often infected with both types of parasites. Although the effect of helminths on malaria infection is evident, the impact of these co-infections is not clearly elucidated yet and the scarce findings are conflicting. In this study, we investigated the effect of schistosomiasis, considering soil-transmitted helminths (STH), on prevalence and incidence of Plasmodium falciparum infection. Methodology This longitudinal survey was conducted in school-age children living in two rural communities in the vicinity of Lambaréné, Gabon. Thick blood smear light microscopy, urine filtration and the Kato-Katz technique were performed to detect malaria parasites, S. haematobium eggs and, STH eggs, respectively. P. falciparum carriage was assessed at inclusion, and incidence of malaria and time to the first malaria event were recorded in correlation with Schistosoma carriage status. Stratified multivariate analysis using generalized linear model was used to assess the risk of plasmodium infection considering interaction with STH, and survival analysis to assess time to malaria. Main findings The overall prevalence on subject enrolment was 30%, 23% and 9% for S. haematobium, P. falciparum infections and co-infection with both parasites, respectively. Our results showed that schistosomiasis in children tends to increase the risk of plasmodium infection but a combined effect with Trichuris trichiura or hookworm infection clearly increase the risk (aOR = 3.9 [95%CI: 1.7–9.2]). The incidence of malaria over time was 0.51[95%CI: 0.45–0.57] per person-year and was higher in the Schistosoma-infected group compared to the non-infected group (0.61 vs 0.43, p = 0.02), with a significant delay of time-to first-malaria event only in children aged from 6 to 10-years-old infected with Schistosoma haematobium. Conclusions Our results suggest that STH enhance the risk for P. falciparum infection in schistosomiasis-positive children, and when infected, that schistosomiasis enhances susceptibility to developing malaria in young children but not in older children., Author summary Despite the progress made in the last decade, malaria remains a serious public health issue in sub-Saharan region, where it overlaps with helminths infections. The interactions between both are manifold and complex, requiring further investigation. We report here that Trichuris trichiura or hookworm associated with schistosomiasis increase the risk of Plasmodium falciparum infection; whilst schistosomiasis is independently associated with a malaria increase in young children, but not in the older children. Our finding is an additional evidence that optimizing helminth control mainly in children contributes to overcoming malaria in areas endemic for both parasitic infections where children are those who bear the highest burden of these infections.

Cystic echinococcosis (CE) is a globally endemic zoonosis caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) complex. Although the disease is known to be highly prevalent in certain parts of North and East Africa, data on CE, both in humans and definitive hosts, are extremely scarce for Central Africa. The present study assessed the epidemiology of CE in humans and dogs in rural Gabon. An ultrasound and serologic survey was conducted in volunteers from rural villages in Gabon. A two-step approach was used for serological testing with an indirect hemagglutination assay as a screening test and Western Blot as a confirmatory test. Fecal dog samples were analyzed microscopically, and polymerase chain reaction (PCR) amplification of nad1 and cox1 genes was performed when taeniid eggs were visible. Regional hospitals and the national reference center for parasitology in Gabon were contacted for information about previous cases of CE. Randomly selected communities were invited to participate. Three hundred and forty-eight human volunteers from these communities were screened. No suspected cases of CE were detected. Definitive host screening was performed from 128 fecal samples from representative subregions, but no eggs from E. granulosus s.l. were found. No documented cases of echinococcosis were reported from the local health-care institutions and the national diagnostic reference center in Gabon. Cystic echinococcosis seems to be very rare or absent in Gabon. The reason for this lack of evidence for echinococcosis is unknown, but the absence of livestock may play a major role.

Background Diagnosis of malaria is usually based on samples of peripheral blood. However, it is unclear whether capillary (CAP) or venous (VEN) blood samples provide better diagnostic performance. Quantitative differences of parasitemia between CAP and VEN blood and diagnostic performance characteristics were investigated. Methods Patients were recruited between September 2015 and February 2016 in Gabon. Light microscopy and quantitative polymerase chain reaction (qPCR) measured parasitemia of paired CAP and VEN samples. CAP and VEN performance characteristics using microscopy were evaluated against a qPCR gold standard. Results Microscopy revealed a median parasitemia of 495/μL in CAP and 429/μL in VEN samples, manifesting in a 16.6% (P = .04) higher CAP parasitemia compared with VEN parasitemia. Concordantly, in qPCR -0.278 (P = .006) cycles were required for signal detection in CAP samples. CAP sensitivity of microscopy relative to the gold standard was 81.5% vs VEN sensitivity of 73.4%, while specificities were 91%. CAP and VEN sensitivities dropped to 63.3% and 45.9%, respectively, for a subpopulation of low-level parasitemias, whereas specificities were 92%. Conclusions CAP sampling leads to higher parasitemias compared to VEN sampling and improves diagnostic sensitivity. These findings may have important implications for routine diagnostics, research, and elimination campaigns of malaria.

Malaria is among the major threats to global health with the main burden of disease being in rural areas of developing countries where accurate diagnosis based on non-invasive samples is in high demand. We here present a novel molecular assay for detection of malaria parasites based on technology that may be adapted for low-resource settings. Moreover, we demonstrate the exploitation of this assay for detection of malaria in saliva. The setup relies on pump-free microfluidics enabled extraction combined with a DNA sensor substrate that is converted to a single-stranded DNA circle specifically by topoisomerase I expressed by the malaria causing Plasmodium parasite. Subsequent rolling circle amplification of the generated DNA circle in the presence of biotin conjugated deoxynucleotides resulted in long tandem repeat products that was visualized colorimetrically upon binding of horse radish peroxidase (HRP) and addition of 3,3′,5,5′-Tetramethylbenzidine that was converted to a blue colored product by HRP. The assay was directly quantitative, specific for Plasmodium parasites, and allowed detection of Plasmodium infection in a single drop of saliva from 35 out of 35 infected individuals tested. The results could be determined directly by the naked eye and documented by quantifying the color intensity using a standard paper scanner.

Rapid and reliable diagnosis is essential in the fight against malaria, which remains one of the most deadly infectious diseases in the world. In the present study we take advantage of a droplet microfluidics platform combined with a novel and user-friendly biosensor for revealing the main malaria-causing agent, the Plasmodium falciparum (P. falciparum) parasite. Detection of the parasite is achieved through detection of the activity of a parasite-produced DNA-modifying enzyme, topoisomerase I (pfTopoI), in the blood from malaria patients. The assay presented has three steps: (1) droplet microfluidics-enabled extraction of active pfTopoI from a patient blood sample, (2) pfTopoI-mediated modification of a specialized DNA biosensor, (3) readout. The setup is quantitative and specific for the detection of Plasmodium topoisomerase I. The procedure is a considerable improvement of the previously published Rolling Circle Enhanced Enzyme Activity Detection (REEAD) due to the advantages of involving no signal amplification steps combined with a user-friendly readout. In combination these alterations represent an important step towards exploiting enzyme activity detection in point-of-care diagnostics of malaria.

Treatment recommendations for Plasmodium malariae and Plasmodium ovale malaria are largely based on anecdotal evidence. The aim of this prospective study, conducted in Gabon, was to systematically assess the efficacy and safety of artemether-lumefantrine for the treatment of patients with uncomplicated P. malariae or P. ovale species monoinfections or mixed Plasmodium infections. Patients with microscopically confirmed P. malariae , P. ovale , or mixed-species malaria with at least one of these two Plasmodium species were treated with an oral, fixed-dose combination of artemether-lumefantrine for 3 consecutive days. The primary endpoints were per-protocol PCR-corrected adequate clinical and parasitological response (ACPR) on days 28 and 42. Tolerability and safety were recorded throughout the follow-up period. Seventy-two participants (42 male and 30 female) were enrolled; 62.5% of them had PCR-corrected mixed Plasmodium infections. Per protocol, PCR-corrected ACPR rates were 96.6% (95% confidence interval [CI], 91.9 to 100) on day 28 and 94.2% (95% CI, 87.7 to 100) on day 42. Considering Plasmodium species independently from their coinfecting species, day 42 ACPR rates were 95.5% (95% CI, 89.0 to 100) for P. falciparum , 100% (exact CI, 84.6 to 100) for P. malariae , 100% (exact CI, 76.8 to 100) for P. ovale curtisi , and 90.9% (95% CI, 70.7 to 100) for P. ovale wallikeri . Study drug-related adverse events were generally mild or moderate. In conclusion, this clinical trial demonstrated satisfying antimalarial activity of artemether-lumefantrine against P. ovale wallikeri , P. ovale curtisi , P. malariae , and mixed Plasmodium infections, with per-protocol efficacies of 90% to 100% and without evident tolerability or safety concerns. (This trial was registered in the clinical study database ClinicalTrials.gov under the identifier NCT02528279.)

BackgroundMalaria remains a public health issue particularly in sub-Saharan Africa with special features of seriousness in young children and pregnant women. Older children and adults reported to have acquired a semi-immune status and therefore show low parasitaemia and less pronounced symptoms if any. We aim to explore parasitaemia and symptoms in adolescents and adults with malaria compared to younger children in the Lambaréné area.MethodsWe conducted a cross-sectional study in CERMEL for a month in 2018. Adults and children were screened for malaria at health facilities in Lambaréné and Fougamou and their respective surrounding villages in the central region of Gabon. Malaria infection was determined either by rapid diagnostic test (RDT) or by thick blood smear (TBS). Body temperature, history of fever, age, sex, haemoglobin level, and location were collected.ResultsFrom 09 January to 09 February 2018, a total of 596 patients were screened and 280 (47%) belonged to the adult population. Plasmodium falciparum infection in adults was diagnosed based on the detection of P. falciparum in thick blood films. Prevalence among the adults was 56% (n=141); 34% of adult patients had a parasite count between 1015–116,079 pf/µl. Fever was found in 31% of adults and several symptoms were reported by the same patient. Vomiting, loss of appetite, and fatigue were significantly more present in the adult population than in children.ConclusionThis study shows a high rate of Plasmodium falciparum infection in adults associated to clinical symptoms and high level of parasitaemia. Adults seem to become an at-risk population, suggesting that malaria programmes should consider including adults in the implementation of a malaria prevention programme.

Toxocara spp. are zoonotic parasites with global distribution infecting humans by incidental ingestions of eggs shed in feces of dogs or cats. High seroprevalences have been reported from several regions of Africa, however data from the Central African region remain limited. Although several clinical entities caused by larvae of Toxocara spp. have been described, the public heath impact of this infection has so far often been neglected. This study was conducted to estimate the prevalence in a rural central African population.The population based study was performed in volunteers in a rural region of Gabon. A two-step testing approach was applied using an ELISA as screening test and a Western Blot (immunoblot) as confirmatory assay. Basic demographic data and risk factors were collected and compared between seropositive and negative participants.In total, 199 out of 332 serum samples were tested positive for Toxocara spp. antibodies (59.9%). After standardization for age to the overall Gabonese population seroprevalence was 53.6% (95% CI 48.2–59.0%). There was a trend towards higher seroprevalence in participants with agricultural activity.Seroprevalence of antibodies against Toxocara spp. is high in this rural population in Gabon. These results are comparable with previous reports from other sub-regions of Africa and add to our understanding of the epidemiology of toxocariasis in Africa. Given the high prevalence of toxocariasis in tropical regions, it may be speculated that clinically relevant presentations (e.g. visceral or ocular larva migrans syndrome) may occur in considerable numbers. A formal assessment of the burden of disease and the public health impact of human toxocariasis is therefore warranted.

Plasmodium falciparum, the most common malarial parasite in sub-Saharan Africa, accounts for a high number of deaths in children less than five years of age. In malaria-endemic countries with stable transmission, semi-immunity is usually acquired after childhood. For adults, severe malaria is rare. Infected adults have either uncomplicated malaria or asymptomatic parasitemia. During a period of one year, we screened 497 afebrile males to investigate the prevalence of asymptomatic P. falciparum parasitemia in villages near Lambarene, Gabon by use of three different methods. A total of 52% of the individuals had parasites detected by a subtelomeric variable open reading frame polymerase chain reaction (stevor-PCR), 27% of the rapid diagnostic test results were positive, and 12% of the thick blood smears with low parasitemias had P. falciparum. Most positive cases were only detected by the stevor-PCR. Asymptomatic P. falciparum parasitemia in adults living in a malaria-endemic country is frequent.

To the Editor: Loa loa, the African eye worm, is a filarial pathogen of Central African rainforest regions. As of 2013, it had affected an estimated 2–3 million persons in Central Africa (1,2). Adult worm migrations in humans may intermittently cause Calabar swelling, and microfilariae are commonly found in blood and body fluids. Loiasis is a chronic infection persisting for many years; a considerable proportion of women in loiasis-endemic regions are infected during gestation. To date, the epidemiology of loiasis in pregnant women has not been investigated, and the effects of loiasis on maternal and fetal health outcomes are unknown. We investigated the epidemiology of loiasis in a cohort of pregnant women participating in a drug trial for preventing malaria during pregnancy.

Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended in HIV-negative women to avert malaria, while this relies on cotrimoxazole prophylaxis (CTXp) in HIV-positive women. Alternative antimalarials are required in areas where parasite resistance to antifolate drugs is high. The cost-effectiveness of IPTp with alternative drugs is needed to inform policy. METHODS: The cost-effectiveness of 2-dose IPTp-mefloquine (MQ) was compared with IPTp-SP in HIV-negative women (Benin, Gabon, Mozambique and Tanzania). In HIV-positive women the cost-effectiveness of 3-dose IPTp-MQ added to CTXp was compared with CTXp alone (Kenya, Mozambique and Tanzania). The outcomes used were maternal clinical malaria, anaemia at delivery and non-obstetric hospital admissions. The poor tolerability to MQ was included as the value of women's loss of working days. Incremental cost-effectiveness ratios (ICERs) were calculated and threshold analysis undertaken. RESULTS: For HIV-negative women, the ICER for IPTp-MQ versus IPTp-SP was 136.30 US$ (2012 US$) (95%CI 131.41; 141.18) per disability-adjusted life-year (DALY) averted, or 237.78 US$ (95%CI 230.99; 244.57), depending on whether estimates from Gabon were included or not. For HIV-positive women, the ICER per DALY averted for IPTp-MQ added to CTXp, versus CTXp alone was 6.96 US$ (95%CI 4.22; 9.70). In HIV-negative women, moderate shifts of variables such as malaria incidence, drug cost, and IPTp efficacy increased the ICERs above the cost-effectiveness threshold. In HIV-positive women the intervention remained cost-effective for a substantial (up to 21 times) increase in cost per tablet. CONCLUSIONS: Addition of IPTp with an effective antimalarial to CTXp was very cost-effective in HIV-positive women. IPTp with an efficacious antimalarial was more cost-effective than IPTp-SP in HIV-negative women. However, the poor tolerability of MQ does not favour its use as IPTp. Regardless of HIV status, prevention of malaria in pregnancy with a highly efficacious, well tolerated antimalarial would be cost-effective despite its high price. TRIALS REGISTRATION: ClinicalTrials.gov NCT 00811421; Pan African Trials Registry PACTR2010020001429343 and PACTR2010020001813440.

Background As investment in research related to artemisinin resistance is a key objective of the Global Plan for Artemisinin Resistance Containment (GPARC), fosmidomycin and piperaquine are being developed to address the delay in parasite clearance following treatment with Artemisinin-based Combination Therapy (ACT). Though artemisinin resistance occurs principally in the Greater Mekong Region, there are concerns that it will emerge in sub-Saharan Africa. Methods A proof-of-concept study has been conducted in Gabon to determine the efficacy, tolerance and safety of fosmidomycin and piperaquine when administered orally for three days. A total of 100 subjects, including 10 adults, 40 children aged 5–14 years and 50 children aged 1–5 years fulfilling the inclusion criteria of mono-infection with Plasmodium falciparum and initial parasite counts between 1,000 and 150,000/µL were enrolled and followed up for 63 days. The primary efficacy endpoint was per protocol, the PCR-corrected cure rate on Day 28. Safety endpoints included the incidence, severity, drug-relatedness and seriousness of adverse events and laboratory abnormalities. ClinicalTrials.gov Identifier: NCT02198807 Results The PCR-corrected 28-day cure rate in the older children was 100% (n=31). It was also 100% (n=38) in the younger children, a group deemed to be more therapeutically challenging on account of their lower immune status. Tolerance was excellent and there were no drug-related safety issues. Full results will be presented. Conclusions Fulfilling the WHO criteria for combination therapy, fosmidomycin as a rapidly acting blood schizonticide and piperaquine with its prolonged post-treatment prophylactic effect have been shown to be highly efficacious for the treatment of acute uncomplicated falciparum malaria in an area of intense malaria transmission. Dose optimisation studies with the dual aim of achieving a reduction in the dose of fosmidomycin within a therapeutic regimen of once daily dosing are planned.

Objectives Streptococcus agalactiae constitutes an important cause of neonatal infections in sub-Saharan Africa. Sulfadoxine/pyrimethamine—the current intermittent preventive treatment of malaria in pregnancy (IPTp)—has proven in vitro activity against group B Streptococcus (GBS). Because of specific drug resistance to sulfadoxine/pyrimethamine, mefloquine—an antimalarial without in vitro activity against GBS—was evaluated as a potential alternative. This study assessed the potential of sulfadoxine/pyrimethamine-IPTp to reduce the prevalence of GBS colonization in pregnant women in Gabon when compared with the inactive control mefloquine-IPTp. Methods Pregnant women participating in a randomized controlled clinical trial evaluating mefloquine-IPTp versus sulfadoxine/pyrimethamine-IPTp were invited to participate and recto-vaginal swabs were collected at delivery for detection of GBS colonization. Prevalence of recto-vaginal GBS colonization was compared between IPTp regimens and risk factor and birth outcome analyses were computed. Results Among 549 participants, 106 were positive for GBS colonization at delivery (19%; 95% CI = 16%–23%). Prevalence of maternal GBS colonization showed no significant difference between the two IPTp regimens (mefloquine-IPTp: 67 of 366 women = 18%; 95% CI = 14%–22%; sulfadoxine/pyrimethamine-IPTp: 39 of 183 women = 21%; 95% CI = 15%–27%). Risk factor analysis for GBS colonization demonstrated a significant association with illiteracy (adjusted OR = 2.03; 95% CI = 1.25–3.30). GBS colonization had no impact on birth outcome, anaemia at delivery, gestational age and birth weight. Conclusions Sulfadoxine/pyrimethamine did not reduce colonization rates when used as the IPTp drug during pregnancy. Illiteracy was associated with GBS colonization.

Malaria parasite infections that are only detectable by molecular methods are highly prevalent and represent a potential transmission reservoir. The methods used to detect these infections are not standardized, and their operating characteristics are often unknown. We designed a proficiency panel of Plasmodium spp. in order to compare the accuracy of parasite detection of molecular protocols used by labs in a clinical trial consortium. Ten dried blood spots (DBSs) were assembled that contained P. falciparum , P. vivax , P. malariae , and P. ovale ; DBSs contained either a single species or a species mixed with P. falciparum . DBS panels were tested in 9 participating laboratories in a masked fashion. Of 90 tests, 68 (75.6%) were correct; there were 20 false-negative results and 2 false positives. The detection rate was 77.8% (49/63) for P. falciparum , 91.7% (11/12) for P. vivax , 83.3% (10/12) for P. malariae , and 70% (7/10) for P. ovale . Most false-negative P. falciparum results were from samples with an estimated ≤5 parasites per μl of blood. Between labs, accuracy ranged from 100% to 50%. In one lab, the inability to detect species in mixed-species infections prompted a redesign and improvement of the assay. Most PCR-based protocols were able to detect P. falciparum and P. vivax at higher densities, but these assays may not reliably detect parasites in samples with low P. falciparum densities. Accordingly, formal quality assurance for PCR should be employed whenever this method is used for diagnosis or surveillance. Such efforts will be important if PCR is to be widely employed to assist malaria elimination efforts.

Background Urogenital schistosomiasis is a major public health problem in sub-Saharan Africa, and routine programs for screening and treatment of pregnant women are not established. Mefloquine-currently evaluated as a potential alternative to sulfadoxine-pyrimethamine as intermittent preventive treatment against malaria in pregnancy (IPTp)-is known to exhibit activity against Schistosoma haematobium. In this study we evaluated the efficacy of mefloquine IPTp against S. haematobium infection in pregnant women. Methods Pregnant women with S. haematobium infection presenting at 2 antenatal health care centers in rural Gabon were invited to participate in this nested randomized controlled, assessor-blinded clinical trial comparing sulfadoxine-pyrimethamine with mefloquine IPTp. Study drugs were administered twice during pregnancy with a 1- month interval after completion of the first trimester. Results Sixty-five pregnant women were included in this study. Schistosoma haematobium egg excretion rates showed a median reduction of 98% (interquartile range [IQR], 70%-100%) in the mefloquine group compared to an increase of 20% (IQR, -186% to 75%) in the comparator group. More than 80% of patients showed at least 50% reduction of egg excretion and overall cure rate was 47% (IQR, 36%-70%) 6 weeks after the second administration of mefloquine IPTp. Conclusion When used as IPTp for the prevention of malaria, mefloquine shows promising activity against concomitant S. haematobium infection leading to an important reduction of egg excretion in pregnant women. Provided that further studies confirm these findings, the use of mefloquine may transform future IPTp programs into a 2-pronged intervention addressing 2 of the most virulent parasitic infections in pregnant women in sub-Saharan Africa. Clinical trials registration NCT01132248; ATMR2010020001429343.

Background The recommendation of artemisinin combination therapy (ACT) as first-line treatment for uncomplicated falciparum malaria is supported by a plethora of high quality clinical trials. However, their recommendation for the treatment of mixed-species malaria and the large-scale use for the treatment of non-falciparum malaria in endemic regions is based on anecdotal rather than systematic clinical evidence. Methods This study prospectively observed the efficacy of artemether-lumefantrine for the treatment of uncomplicated non-falciparum or mixed-species malaria in two routine district hospitals in the Central African country of Gabon. Results Forty patients suffering from uncomplicated Plasmodium malariae, Plasmodium ovale or mixed-species malaria (including Plasmodium falciparum) presenting at the hospital received artemether-lumefantrine treatment and were followed up. All evaluable patients (n = 38) showed an adequate clinical and parasitological response on Day 28 after oral treatment with artemether-lumefantrine (95% confidence interval: 0.91,1). All adverse events were of mild to moderate intensity and completely resolved by the end of study. Conclusions This first systematic assessment of artemether-lumefantrine treatment for P. malariae, P. ovale and mixed-species malaria demonstrated a high cure rate of 100% and a favourable tolerability profile, and thus lends support to the practice of treating non-falciparum or mixed-species malaria, or all cases of malaria without definite species differentiation, with artemether-lumefantrine in Gabon. Trial Registration ClinicalTrials.gov Identifier: NCT00725777

Timely treatment of infected children with artemisinin based combination therapies is an essential tool for the effective control and potential elimination of malaria. Until recently only tablet formulations have been available for the treatment of children leading to problems of swallowability, palatability and dosing. In consequence, paediatric drug formulations of artemisinin-based combination therapy (ACT) have been developed, showing a clinically significant improvement of tolerability in young children and of their implementation is an increasingly important public health issue. In this mini-review, we focus on the recent development of paediatric ACTs and their use in practice. Paediatric ACTs are formulated as syrup, powder for suspension, dispersible tablets and granules. Overall, the use of paediatric formulation results in an improved management of clinical malaria in young children. To date, only two paediatric ACTs have been certified with WHO prequalification status as an internationally accepted quality standard. Many more paediatric ACTs are available and in use in sub-Saharan Africa despite a lack of publicly available evidence from stringent clinical development programs. The conduct of effectiveness studies to support the introduction of paediatric ACTs in official treatment recommendations is crucial in the global strategy of malaria elimination and quality assurance of available products is a public health priority.

The increasing resistance of the malaria parasite Plasmodium falciparum to currently available drugs necessitates a continuous effort to develop new antimalarial agents. We therefore aimed to assess the in vitro activity of the antifungal drugs clotrimazole, fluconazole, ketoconazole, itraconazole, voriconazole, flucytosine, amphotericin B, and caspofungin against field isolates of P. falciparum from Lambaréné, Gabon. Using the histidin-rich protein 2 (HRP-2) assay we determined the drug susceptibility (EC(50), EC(90)) of 16 field isolates obtained from outpatients attending the Albert Schweitzer Hospital in Lambaréné, Gabon. For fluconazole, itraconazole and caspofungin the in vitro growth inhibition of these drugs is reported for the first time. Our data indicate that clotrimazole, fluconazole, itraconazole and caspofungin show median EC(50) values of 3.1 µg/mL, 1.9 µg/mL, 1.1 µg/mL and 1.1 µg/mL respectively. Ketoconazole, voriconazole, flucytosine and amphotercin B showed no relevant growth inhibition within the range of drug concentrations used in this study.

Background Chloroquine resistance (CR) decreased after the removal of chloroquine from national treatment guidelines in Malawi, Kenia and Tanzania. In this investigation the prevalence of the chloroquine resistance (CQR) conferring mutant pfcrt allele and its associated chromosomal haplotype were determined before and after the change in Gabonese national treatment guidelines from chloroquine (CQ) to artesunate plus amodiaquine (AQ) in 2003. Methods The prevalence of the wild type pfcrt allele was assessed in 144 isolates from the years 2005 - 07 by PCR fragment restriction digest and direct sequencing. For haplotype analysis of the chromosomal regions flanking the pfcrt locus, microsatellite analysis was done on a total of 145 isolates obtained in 1995/96 (43 isolates), 2002 (47 isolates) and 2005 - 07 (55 isolates). Results The prevalence of the mutant pfcrt allele decreased from 100% in the years 1995/96 and 2002 to 97% in 2005 - 07. Haplotype analysis showed that in 1995/96 79% of the isolates carried the same microsatellite alleles in a chromosomal fragment spanning 39 kb surrounding the pfcrt locus. In 2002 and 2005 - 07 the prevalence of this haplotype was 62% and 58%, respectively. Pfcrt haplotype analysis showed that all wild type alleles were CVMNK. Conclusion Four years after the withdrawal of CQ from national treatment guidelines the prevalence of the mutant pfcrt allele remains at 97%. The data suggest that the combination of artesunate plus AQ may result in continued selection for the mutant pfcrt haplotype even after discontinuance of CQ usage.

Cally Roper and colleagues analyze the distribution of sulfadoxine resistance mutations and flanking microsatellite loci to trace the emergence and dispersal of drug-resistant Plasmodium falciparum malaria in Africa., Background Although the molecular basis of resistance to a number of common antimalarial drugs is well known, a geographic description of the emergence and dispersal of resistance mutations across Africa has not been attempted. To that end we have characterised the evolutionary origins of antifolate resistance mutations in the dihydropteroate synthase (dhps) gene and mapped their contemporary distribution. Methods and Findings We used microsatellite polymorphism flanking the dhps gene to determine which resistance alleles shared common ancestry and found five major lineages each of which had a unique geographical distribution. The extent to which allelic lineages were shared among 20 African Plasmodium falciparum populations revealed five major geographical groupings. Resistance lineages were common to all sites within these regions. The most marked differentiation was between east and west African P. falciparum, in which resistance alleles were not only of different ancestry but also carried different resistance mutations. Conclusions Resistant dhps has emerged independently in multiple sites in Africa during the past 10–20 years. Our data show the molecular basis of resistance differs between east and west Africa, which is likely to translate into differing antifolate sensitivity. We have also demonstrated that the dispersal patterns of resistance lineages give unique insights into recent parasite migration patterns., Editors' Summary Background Plasmodium falciparum, a mosquito-borne parasite that causes malaria, kills nearly one million people every year, mostly in sub-Saharan Africa. People become infected with P. falciparum when they are bitten by a mosquito that has acquired the parasite in a blood meal taken from an infected person. P. falciparum malaria, which is characterized by recurring fevers and chills, anemia (loss of red blood cells), and damage to vital organs, can be fatal within hours of symptom onset if untreated. Until recently, treatment in Africa relied on chloroquine and sulfadoxine–pyrimethamine. Unfortunately, parasites resistant to both these antimalarial drugs is now widespread. Consequently, the World Health Organization currently recommends artemisinin combination therapy for the treatment of P. falciparum malaria in Africa and other places where drug-resistant malaria is common. In this therapy, artemisinin derivatives (new fast-acting antimalarial agents) are used in combination with another antimalarial to reduce the chances of P. falciparum becoming resistant to either drug. Why Was This Study Done? P. falciparum becomes resistant to antimalarial drugs by acquiring “resistance mutations,” genetic changes that prevent these drugs from killing the parasite. A mutation in the gene encoding a protein called the chloroquine resistance transporter causes resistance to chloroquine, a specific group of mutations in the dihydrofolate reductase gene causes resistance to pyrimethamine, and several mutations in dhps, the gene that encodes dihydropteroate synthase, are associated with resistance to sulfadoxine. Scientists have discovered that the mutations causing chloroquine and pyrimethamine resistance originated in Asia and spread into Africa (probably multiple times) in the late 1970s and mid-1980s, respectively. These Asian-derived mutations are now common throughout Africa and, consequently, it is not possible to determine how they spread across the continent. Information of this sort would, however, help experts design effective measures to control the spread of drug-resistant P. falciparum. Because the mutations in dhps that cause sulfadoxine resistance only began to emerge in the mid-1990s, they haven't spread evenly across Africa yet. In this study, therefore, the researchers use genetic methods to characterize the geographical origins and contemporary distribution of dhps resistance mutations in Africa. What Did the Researchers Do and Find? The researchers analyzed dhps mutations in P. falciparum DNA from blood samples collected from patients with malaria in various African countries and searched the scientific literature for other similar studies. Together, these data show that five major variant dhps sequences (three of which contain mutations that confer various degrees of resistance to sulphadoxine in laboratory tests) are currently present in Africa, each with a unique geographical distribution. In particular, the data show that P. falciparum parasites in east and west Africa carry different resistance mutations. Next, the researchers looked for microsatellite variants in the DNA flanking the dhps gene. Microsatellites are DNA regions that contain short, repeated sequences of nucleotides. Because the number of repeats can vary and because microsatellites are inherited together with nearby genes, the ancestry of various resistance mutations can be worked out by examining the microsatellites flanking different mutant dhps genes. This analysis revealed five regional clusters in which the same resistance lineage was present at all the sites examined within the region and also showed that the resistance mutations in east and west Africa have a different ancestry. What Do These Findings Mean? These findings show that sulfadoxine-resistant P. falciparum has recently emerged independently at multiple sites in Africa and that the molecular basis for sulfadoxine resistance is different in east and west Africa. This latter result may have clinical implications because it suggests that the effectiveness of sulfadoxine as an antimalarial drug may vary across the continent. Finally, although many more samples need to be analyzed to build a complete picture of the spread of antimalarial resistance across Africa, these findings suggest that economic and transport infrastructures may have played a role in governing recent parasite dispersal across this continent by affecting human migration. Thus, coordinated malaria control campaigns across socioeconomically linked areas in Africa may reduce the African malaria burden more effectively than campaigns that are confined to national territories. Additional Information Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000055. This study is further discussed in a PLoS Medicine Perspective by Tim Anderson The MedlinePlus encyclopedia contains a page on malaria (in English and Spanish) Information is available from the World Health Organization on malaria (in several languages) and on drug-resistant malaria The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish) Information is available from the Roll Back Malaria Partnership on its approach to the global control of malaria, and on malaria control efforts in specific parts of the world The WorldWide Antimalarial Resistance Network is creating an international database about antimalarial drug resistance

Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine–pyrimethamine has recently been adopted by many African countries to reduce maternal and neonatal morbidity and mortality associated with malaria in pregnancy. We assessed the impact of a newly established national IPTp program on maternal and neonatal health in Gabon. Data on prevalence of maternal Plasmodium falciparum infection, anemia, premature birth, and birth weight were collected in cross-sectional surveys in urban and rural regions of Gabon before and after the implementation of IPTp in a total of 1403 women and their offspring. After introduction of IPTp, the prevalence of maternal Plasmodium falciparum infection decreased dramatically (risk ratio 0.16, P < 0.001). Whereas only a modest effect on the rate of anemia in pregnant women was observed, there was a marked benefit on the prevalence of low birth weight and premature birth for women adhering to national recommendations. These effects were most pronounced in primi- and secundigravid women.

BackgroundIntermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended by WHO to prevent malaria in African pregnant women. The spread of SP parasite resistance has raised concerns regarding long-term use for IPT. Mefloquine (MQ) is the most promising of available alternatives to SP based on safety profile, long half-life, and high efficacy in Africa. We evaluated the safety and efficacy of MQ for IPTp compared to those of SP in HIV-negative women.Methods and findingsA total of 4,749 pregnant women were enrolled in an open-label randomized clinical trial conducted in Benin, Gabon, Mozambique, and Tanzania comparing two-dose MQ or SP for IPTp and MQ tolerability of two different regimens. The study arms were: (1) SP, (2) single dose MQ (15 mg/kg), and (3) split-dose MQ in the context of long lasting insecticide treated nets. There was no difference on low birth weight prevalence (primary study outcome) between groups (360/2,778 [13.0%]) for MQ group and 177/1,398 (12.7%) for SP group; risk ratio [RR], 1.02 (95% CI 0.86-1.22; p=0.80 in the ITT analysis). Women receiving MQ had reduced risks of parasitemia (63/1,372 [4.6%] in the SP group and 88/2,737 [3.2%] in the MQ group; RR, 0.70 [95% CI 0.51-0.96]; p=0.03) and anemia at delivery (609/1,380 [44.1%] in the SP group and 1,110/2743 [40.5%] in the MQ group; RR, 0.92 [95% CI 0.85-0.99]; p=0.03), and reduced incidence of clinical malaria (96/551.8 malaria episodes person/year [PYAR] in the SP group and 130/1,103.2 episodes PYAR in the MQ group; RR, 0.67 [95% CI 0.52-0.88]; p=0.004) and all-cause outpatient attendances during pregnancy (850/557.8 outpatients visits PYAR in the SP group and 1,480/1,110.1 visits PYAR in the MQ group; RR, 0.86 [0.78-0.95]; p=0.003). There were no differences in the prevalence of placental infection and adverse pregnancy outcomes between groups. Tolerability was poorer in the two MQ groups compared to SP. The most frequently reported related adverse events were dizziness (ranging from 33.9% to 35.5% after dose 1; and 16.0% to 20.8% after dose 2) and vomiting (30.2% to 31.7%, after dose 1 and 15.3% to 17.4% after dose 2) with similar proportions in the full and split MQ arms. The open-label design is a limitation of the study that affects mainly the safety assessment.ConclusionsWomen taking MQ IPTp (15 mg/kg) in the context of long lasting insecticide treated nets had similar prevalence rates of low birth weight as those taking SP IPTp. MQ recipients had less clinical malaria than SP recipients, and the pregnancy outcomes and safety profile were similar. MQ had poorer tolerability even when splitting the dose over two days. These results do not support a change in the current IPTp policy.Trial registrationClinicalTrials.gov NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001429343 Please see later in the article for the Editors' Summary.

The Four Artemisinin-Based Combinations (4ABC) Study Group reports a randomized, non-inferiority trial comparing the efficacy and safety of four ACTs in children with mild Plasmodium falciparum malaria from seven sub-Saharan African countries., Background Artemisinin-based combination therapies (ACTs) are the mainstay for the management of uncomplicated malaria cases. However, up-to-date data able to assist sub-Saharan African countries formulating appropriate antimalarial drug policies are scarce. Methods and Findings Between 9 July 2007 and 19 June 2009, a randomized, non-inferiority (10% difference threshold in efficacy at day 28) clinical trial was carried out at 12 sites in seven sub-Saharan African countries. Each site compared three of four ACTs, namely amodiaquine-artesunate (ASAQ), dihydroartemisinin-piperaquine (DHAPQ), artemether-lumefantrine (AL), or chlorproguanil-dapsone-artesunate (CD+A). Overall, 4,116 children 6–59 mo old with uncomplicated Plasmodium falciparum malaria were treated (1,226 with AL, 1,002 with ASAQ, 413 with CD+A, and 1,475 with DHAPQ), actively followed up until day 28, and then passively followed up for the next 6 mo. At day 28, for the PCR-adjusted efficacy, non-inferiority was established for three pair-wise comparisons: DHAPQ (97.3%) versus AL (95.5%) (odds ratio [OR]: 0.59, 95% CI: 0.37–0.94); DHAPQ (97.6%) versus ASAQ (96.8%) (OR: 0.74, 95% CI: 0.41–1.34), and ASAQ (97.1%) versus AL (94.4%) (OR: 0.50, 95% CI: 0.28–0.92). For the PCR-unadjusted efficacy, AL was significantly less efficacious than DHAPQ (72.7% versus 89.5%) (OR: 0.27, 95% CI: 0.21–0.34) and ASAQ (66.2% versus 80.4%) (OR: 0.40, 95% CI: 0.30–0.53), while DHAPQ (92.2%) had higher efficacy than ASAQ (80.8%) but non-inferiority could not be excluded (OR: 0.35, 95% CI: 0.26–0.48). CD+A was significantly less efficacious than the other three treatments. Day 63 results were similar to those observed at day 28. Conclusions This large head-to-head comparison of most currently available ACTs in sub-Saharan Africa showed that AL, ASAQ, and DHAPQ had excellent efficacy, up to day 63 post-treatment. The risk of recurrent infections was significantly lower for DHAPQ, followed by ASAQ and then AL, supporting the recent recommendation of considering DHAPQ as a valid option for the treatment of uncomplicated P. falciparum malaria. Trial Registration ClinicalTrials.gov NCT00393679; Pan African Clinical Trials Registry PACTR2009010000911750 Please see later in the article for the Editors' Summary, Editors' Summary Background Malaria is a global public-health problem. Half the world's population is at risk of this mosquito-borne parasitic disease, which kills a million people (mainly children living in sub-Saharan Africa) every year. Although several parasites cause malaria, Plasmodium falciparum is responsible for most of these deaths. During the second half of the 20th century, the main treatments for malaria were inexpensive “monotherapies” such as chloroquine and sulfadoxine-pyrimethamine. Unfortunately, the malaria parasite quickly developed resistance to many of these monotherapies, and in the 1990 s, there was a widespread upsurge in P. falciparum malaria. To combat this increase, the World Health Organization (WHO) now recommends artemisinin-based combination therapy (ACT) for first-line treatment of P. falciparum malaria in all regions where there is drug-resistant malaria. In ACT, artemisinin derivatives (new, fast-acting antimalarial drugs) are used in combination with another antimalarial drug (a partner drug) to reduce the chances of P. falciparum becoming resistant to either drug. Why Was This Study Done? WHO currently recommends five ACTs—amodiaquine-artesunate (ASAQ), dihydroartemisinin-piperaquine (DHAPQ), artemether-lumefantrine (AL), artesunate-mefloquine, and artesunate-sulfadoxine-pyrimethamine—for the treatment of malaria. Its treatment guidelines state that the choice of ACT in a country or region should be based on the local level of resistance to the non-artemisinin-based partner drug in the combination. However, data on resistance levels to these partner drugs are scarce or unavailable for many sub-Saharan African countries. To help these countries make an informed choice about their national antimalarial treatment policies, in this randomized, non-inferiority trial, the researchers compare the efficacy and safety of four ACTs in African children with uncomplicated (mild) P. falciparum malaria. In a randomized trial, groups of randomly chosen patients with a specific disease are given different treatments and then followed to compare the outcomes of these interventions. A non-inferiority trial investigates whether one treatment is not worse than another treatment. What Did the Researchers Do and Find? Each of twelve sites in seven sub-Saharan African countries compared three ACTs out of ASAQ, DHAPQ, AL, and chlorproguanil-dapsone-artesunate (CD+A). Overall, 4,116 young children with uncomplicated malaria were treated with ACT, actively followed up for 28 days (their parents brought them back to the site for pre-arranged check-ups), and passively followed up for six months (parents brought their children back if they developed any illnesses). At each visit, blood samples were examined for the presence of parasites, and a technique called PCR was used to determine which cases of malaria were new infections and which were recurrences of the original infection. The researchers then calculated the percentage of patients with no infection or with a new infection (the PCR-adjusted adequate clinical and parasitological response [ACPR]) and the percentage of patients with no infection (the PCR-unadjusted ACPR). For the PCR-adjusted efficacy, three pair-wise comparisons (DHAPQ versus AL, DHAPQ versus ASAQ, and ASAQ versus AL) showed non-inferiority at 28 days. That is, for example, similar percentages of patients given DHAPQ or AL (97.3% and 95.5%, respectively) had either no infection or a new infection. CD+A was less efficacious than the other three treatments. For the PCR-unadjusted efficacy, AL was significantly less efficacious than DHAPQ and ASAQ; DHAPQ had a higher efficacy than ASAQ, but non-inferiority could not be excluded. That is, the difference in efficacy of these two drugs might have happened by chance. What Do These Findings Mean? These findings suggest that AL, ASAQ, and DHAPQ are all efficacious for the treatment of uncomplicated malaria in children; CD+A was withdrawn partway through the trial because of side effects, but these findings also suggest that it was less efficacious than the other ACTs. Importantly, the PCR-unadjusted results indicate that the risk of children becoming re-infected with malaria parasites soon after treatment was lowest for DHAPQ, followed by ASAQ, and then AL. Because these findings are based on pooled results from seven sub-Saharan African countries, they are likely to be generalizable and thus of use in setting national antimalarial drug policies throughout the region. AL and ASAQ are already included in the antimalarial drug policies of many sub-Saharan African countries, note the researchers, but these findings support the WHO recommendation that DHAPQ should also be considered for the treatment for uncomplicated P. falciparum malaria. Additional Information Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001119. Information is available from WHO on malaria (in several languages); the 2010 World Malaria Report provides details of the current global malaria situation; the WHO Guidelines for the Treatment of Malaria and the report Assessment and Monitoring of Antimalarial Drug Efficacy for the Treatment of Uncomplicated Malaria are available The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish), including a selection of personal stories about malaria Information is available from the Roll Back Malaria Partnership on the global control of malaria including fact sheets about ACTs and about malaria in Africa MedlinePlus provides links to additional information on malaria (in English and Spanish)

BackgroundSub-Saharan Africa has the highest rates of maternal and neonatal mortality worldwide. Young maternal age at delivery has been proposed as risk factor for adverse pregnancy outcome, yet there is insufficient data from Sub-Saharan Africa. The present study aimed to investigate the influence of maternal adolescence on pregnancy outcomes in the Central African country Gabon.Methodology and principal findingsData on maternal age, parity, birth weight, gestational age, maternal Plasmodium falciparum infection, use of bednets, and intake of intermittent preventive treatment of malaria in pregnancy were collected in a cross-sectional survey in 775 women giving birth in three mother-child health centers in Gabon. Adolescent women (≤16 years of age) had a significantly increased risk to deliver a baby with low birth weight in univariable analysis (22.8%, 13/57, vs. 9.3%, 67/718, OR: 2.9, 95% CI: 1.5-5.6) and young maternal age showed a statistically significant association with the risk for low birth weight in multivariable regression analysis after correction for established risk factors (OR: 2.7; 95% CI: 1.1-6.5). In further analysis adolescent women were shown to attend significantly less antenatal care visits than adult mothers (3.3±1.9 versus 4.4±1.9 mean visits, pConclusionOur data demonstrate the importance of adolescent age as risk factor for adverse pregnancy outcome. Antenatal care programs specifically tailored for the needs of adolescents may be necessary to improve the frequency of antenatal care visits and pregnancy outcomes in this risk group in Central Africa.

Background Drug resistance contributes to the global malaria burden. Plasmodium falciparum dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) polymorphisms confer resistance to sulphadoxine-pyrimethamine (SP). Methods The study assessed the frequency of SP resistance-conferring polymorphisms in Plasmodium falciparum-positive samples from two clinical studies in Lambaréné. Their role on treatment responses and transmission potential was studied in an efficacy open-label clinical trial with a 28-day follow-up in 29 children under five with uncomplicated malaria. Results SP was well tolerated by all subjects in vivo. Three subjects were excluded from per-protocol analysis. PCR-corrected, 12/26 (46%) achieved an adequate clinical and parasitological response, 13/26 (50%) were late parasitological failures, while 1/26 (4%) had an early treatment failure, resulting in early trial discontinuation. Of 106 isolates, 98 (92%) carried the triple mutant dhfr haplotype. Three point mutations were found in dhps in a variety of haplotypic configurations. The 437G + 540E double mutant allele was found for the first time in Gabon. Conclusions There is a high prevalence of dhfr triple mutant with some dhps point mutations in Gabon, in line with treatment failures observed, and molecular markers of SP resistance should be closely monitored. Trial Registration ClinicalTrials.gov: NCT00453856