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INTRODUCTION: Screening for G6PD deficiency can inform disease management including malaria. Treatment with the antimalarial drugs primaquine and tafenoquine can be guided by point-of-care testing for G6PD deficiency. METHODS AND FINDINGS: Data from similar clinical studies evaluating the performance of the STANDARD G6PD Test (SD Biosensor, South Korea) conducted in Bangladesh, Brazil, Ethiopia, India, Thailand, the United Kingdom, and the United States were pooled. Test performance was assessed in a retrospective analysis on capillary and venous specimens. All study sites used spectrophotometry for reference G6PD testing, and either the HemoCue or complete blood count for reference hemoglobin measurement. The sensitivity of the STANDARD G6PD Test using the manufacturer thresholds for G6PD deficient and intermediate cases in capillary specimens from 4212 study participants was 100% (95% Confidence Interval (CI): 97.5%-100%) for G6PD deficient cases with 60% on the reference assay. The negative predictive value for females with G6PD activity >60% was 99.6% (95% CI 99.1%-99.8%) on capillary specimens. Sensitivity among 396 P. vivax malaria cases was 100% (69.2%-100.0%) for both deficient and intermediate cases. Across the full dataset, 37% of those classified as G6PD deficient or intermediate resulted from true normal cases. Despite this, over 95% of cases would receive correct treatment with primaquine, over 87% of cases would receive correct treatment with tafenoquine, and no true G6PD deficient cases would be treated inappropriately based on the result of the STANDARD G6PD Test. CONCLUSIONS: The STANDARD G6PD Test enables safe access to drugs which are contraindicated for individuals with G6PD deficiency. Operational considerations will inform test uptake in specific settings.

Background Malaria continues to pose a significant burden in endemic countries, many of which lack access to molecular surveillance. Insights from malaria cases in travellers returning to non-endemic areas can provide valuable data to inform endemic country programmes. To evaluate the potential for novel global insights into malaria, we examined epidemiological and molecular data from imported malaria cases to Australia. Methods We analysed malaria cases reported in Australia from 2012 to 2022 using National Notifiable Disease Surveillance System data. Molecular data on imported malaria cases were obtained from literature searches. Results Between 2012 and 2022, 3204 malaria cases were reported in Australia. Most cases (69%) were male and 44% occurred in young adults aged 20–39 years. Incidence rates initially declined between 2012 and 2015, then increased until 2019. During 2012–2019, the incidence in travellers ranged from 1.34 to 7.71 per 100 000 trips. Cases were primarily acquired in Sub-Saharan Africa (n  = 1433; 45%), Oceania (n  = 569; 18%) and Southern and Central Asia (n  = 367; 12%). The most common countries of acquisition were Papua New Guinea (n  = 474) and India (n  = 277). Plasmodium falciparum accounted for 58% (1871/3204) of cases and was predominantly acquired in Sub-Saharan Africa, and Plasmodium vivax accounted for 32% (1016/3204), predominantly from Oceania and Asia. Molecular studies of imported malaria cases to Australia identified genetic mutations and deletions associated with drug resistance and false-negative rapid diagnostic test results, and led to the establishment of reference genomes for P. vivax and Plasmodium malariae. Conclusions Our analysis highlights the continuing burden of imported malaria into Australia. Molecular studies have offered valuable insights into drug resistance and diagnostic limitations, and established reference genomes. Integrating molecular data into national surveillance systems could provide important infectious disease intelligence to optimize treatment guidelines for returning travellers and support endemic country surveillance programmes. [ABSTRACT FROM AUTHOR]

Objective To determine household and health-care provider costs associated with Plasmodium vivax infection across a range of endemic settings. Methods We collected cost data alongside three multicentre clinical trials of P vivax treatment in Afghanistan, Brazil, Colombia, Ethiopia, Indonesia, Philippines, Peru, Thailand and Viet Nam conducted between April 2014 to December 2017. We derived household costs from trial participant surveys administered at enrolment and again 2 weeks later to determine the costs of treatment and transportation, and the number of days that patients and their household caregivers were unable to undertake their usual activities. We determined costs of routine care by health-care providers by micro-costing the resources used to diagnose and treat P vivax at the study sites. Findings The mean total household costs ranged from 8.7 United States dollars (US$; standard deviation, SD: 4.3) in Afghanistan to US$ 254.7 (SD: 148.4) in Colombia. Across all countries, productivity losses were the largest household cost component, resulting in mean indirect costs ranging from US$ 5.3 (SD: 3.0) to US$ 220.8 (SD: 158.40). The range of health-care provider costs for routine care was US$ 3.6-6.6. The cost of administering a glucose-6-phosphate-dehydrogenase rapid diagnostic test, ranged from US$ 0.9 to 13.5, consistently lower than the costs of the widely-used fluorescent spot test (US$ 6.3 to 17.4). Conclusion An episode of P vivax malaria results in high costs to households. The costs of diagnosing and treating P vivax are important inputs for future cost-effectiveness analyses to ensure optimal allocation of resources for malaria elimination. Objectif Determiner les couts, pour les menages et les prestataires de soins, associes a l'infection par Plasmodium vivax dans differentes zones endemiques. Methodes Nous avons recueilli des donnees sur les couts a l'occasion de trois essais cliniques multicentres relatifs au traitement contre P vivax menes en Afghanistan, au Bresil, en Colombie, en Ethiopie, en Indonesie, aux Philippines, au Perou, en Thailande et au Viet Nam entre avril 2014 et decembre 2017. Nous avons calcule les couts pour les menages a partir d'enquetes realisees aupres des participants aux essais, lors de leur admission puis 2 semaines plus tard, afin de determiner les couts de traitement et de transport ainsi que le nombre de jours ou les patients et leurs aidants familiaux n'avaient pu accomplir leurs activites habituelles. Nous avons determine le cout des soins courants par les prestataires de soins en calculant le cout individuel des ressources utilisees pour diagnostiquer et traiter P vivax sur le site des etudes. Resultats Les couts totaux moyens pour les menages allaient de 8.7 dollars des Etats-Unis ($ US; ecart type, ET: 4,3) en Afghanistan a 254.7 $ US (ET: 148,4) en Colombie. Tous pays confondus, les pertes de productivity etaient la principale composante des couts pour les menages, puisqu'elles entrainaient des couts indirects moyens allant de 5,3 $ US (ET: 3,0) a 220,8 $ US (ET: 158,40). En ce qui concerne les prestataires de soins, le cout des soins courants allait de 3,6 a 6,6 $ US. Le cout de realisation d'un test de diagnostic rapide base sur le glucose6- phosphate-deshydrogenase variait de 0,9 $ US a 13,5 $ US, un cout toujours inferieur a celui du tres repandu test par fluorescence (6,3 $ US a 17,4 $ US). Conclusion Un episode de paludisme a P vivax entraine des couts eleves pour les menages. Connaitre les couts du diagnostic et du traitement de P vivax sera fort utile aux futures analyses cout-efficacite. Cela permettra d'affecter les ressources de maniere optimale en vue d'eradiquer le paludisme. Objetivo Determinar los costos del hogar y de los proveedores de atencion de la salud asociados con la infeccion por Plasmodium vivax en una variedad de ambitos endemicos. Metodos Se recopilaron datos de costos junto con tres ensayos clinicos multicentricos del tratamiento con P. vivax en Afganistan, Brasil, Colombia, Etiopia, Filipinas, Indonesia, Peru, Tailandia y Vietnam realizados entre abril de 2014 y diciembre de 2017. Los costos del hogar se derivaron de las encuestas de los participantes del ensayo administradas en el momento de la inscripcion y de nuevo dos semanas despues para determinar los costos del tratamiento y del transporte, asi como el numero de dias en que los pacientes y los cuidadores en el hogar no pudieron llevar a cabo sus actividades habituales. Se determinaron los costos de la atencion de rutina por parte de los proveedores de atencion de la salud mediante el microcosto de los recursos utilizados para diagnosticar y tratar el P. vivax en los centros de estudio. Resultados Los costos totales promedio de los hogares oscilaron entre 8,7 dolares estadounidenses (USD; desviacion estandar, DE: 4,3) en Afganistan y 254,7 USD (DE: 148,4) en Colombia. En todos los paises, las perdidas de productividad fueron el mayor componente del costo del hogar, lo que dio lugar a costos indirectos promedios que oscilaron entre 5,3 y 220,8 USD. El rango de los costos de los proveedores de atencion de la salud para la atencion de rutina fue de 3,6 a 6,6 USD. El costo por administrar una prueba de diagnostico rapido de la glucosa-6- fosfatodeshidrogenasa, vario de 0,9 a 13,5 USD, consistentemente mas bajo que los costos de la prueba de fluorescencia aleatoria ampliamente utilizada (6,3 a 17,4 USD). Conclusion Un episodio de malaria por P. vivax tiene como resultado un alto costo para el hogar. Los costos del diagnostico y tratamiento de P. vivax son insumos importantes para futuros analisis de costoefectividad que aseguren una asignacion optima de recursos para la eliminacion de la malaria., Introduction Outside Sub-Saharan Africa, Plasmodium vivax is now the predominant cause of malaria, affecting 14.0 million patients in 2016. (1) While cost-effectiveness analyses can inform the efficient provision of health-care [...]

BackgroundArtemisinin-resistant Plasmodium falciparum has emerged in the Greater Mekong sub-region and poses a major global public health threat. Slow parasite clearance is a key clinical manifestation of reduced susceptibility to artemisinin. This study was designed to establish the baseline values for clearance in patients from Sub-Saharan African countries with uncomplicated malaria treated with artemisinin-based combination therapies (ACTs).MethodsA literature review in PubMed was conducted in March 2013 to identify all prospective clinical trials (uncontrolled trials, controlled trials and randomized controlled trials), including ACTs conducted in Sub-Saharan Africa, between 1960 and 2012. Individual patient data from these studies were shared with the WorldWide Antimalarial Resistance Network (WWARN) and pooled using an a priori statistical analytical plan. Factors affecting early parasitological response were investigated using logistic regression with study sites fitted as a random effect. The risk of bias in included studies was evaluated based on study design, methodology and missing data.ResultsIn total, 29,493 patients from 84 clinical trials were included in the analysis, treated with artemether-lumefantrine (n = 13,664), artesunate-amodiaquine (n = 11,337) and dihydroartemisinin-piperaquine (n = 4,492). The overall parasite clearance rate was rapid. The parasite positivity rate (PPR) decreased from 59.7 % (95 % CI: 54.5-64.9) on day 1 to 6.7 % (95 % CI: 4.8-8.7) on day 2 and 0.9 % (95 % CI: 0.5-1.2) on day 3. The 95th percentile of observed day 3 PPR was 5.3 %. Independent risk factors predictive of day 3 positivity were: high baseline parasitaemia (adjusted odds ratio (AOR) = 1.16 (95 % CI: 1.08-1.25); per 2-fold increase in parasite density, P 37.5 °C) (AOR = 1.50 (95 % CI: 1.06-2.13), P = 0.022); severe anaemia (AOR = 2.04 (95 % CI: 1.21-3.44), P = 0.008); areas of low/moderate transmission setting (AOR = 2.71 (95 % CI: 1.38-5.36), P = 0.004); and treatment with the loose formulation of artesunate-amodiaquine (AOR = 2.27 (95 % CI: 1.14-4.51), P = 0.020, compared to dihydroartemisinin-piperaquine).ConclusionsThe three ACTs assessed in this analysis continue to achieve rapid early parasitological clearance across the sites assessed in Sub-Saharan Africa. A threshold of 5 % day 3 parasite positivity from a minimum sample size of 50 patients provides a more sensitive benchmark in Sub-Saharan Africa compared to the current recommended threshold of 10 % to trigger further investigation of artemisinin susceptibility.

There is an urgent need for new drugs to treat malaria, with broad therapeutic potential and novel modes of action, to widen the scope of treatment and to overcome emerging drug resistance. Here we describe the discovery of DDD107498, a compound with a potent and novel spectrum of antimalarial activity against multiple life-cycle stages of the Plasmodium parasite, with good pharmacokinetic properties and an acceptable safety profile. DDD107498 demonstrates potential to address a variety of clinical needs, including single-dose treatment, transmission blocking and chemoprotection. DDD107498 was developed from a screening programme against blood-stage malaria parasites; its molecular target has been identified as translation elongation factor 2 (eEF2), which is responsible for the GTP-dependent translocation of the ribosome along messenger RNA, and is essential for protein synthesis. This discovery of eEF2 as a viable antimalarial drug target opens up new possibilities for drug discovery.

BackgroundArtesunate-amodiaquine (AS-AQ) is one of the most widely used artemisinin-based combination therapies (ACTs) to treat uncomplicated Plasmodium falciparum malaria in Africa. We investigated the impact of different dosing strategies on the efficacy of this combination for the treatment of falciparum malaria.MethodsIndividual patient data from AS-AQ clinical trials were pooled using the WorldWide Antimalarial Resistance Network (WWARN) standardised methodology. Risk factors for treatment failure were identified using a Cox regression model with shared frailty across study sites.ResultsForty-three studies representing 9,106 treatments from 1999-2012 were included in the analysis; 4,138 (45.4%) treatments were with a fixed dose combination with an AQ target dose of 30 mg/kg (FDC), 1,293 (14.2%) with a non-fixed dose combination with an AQ target dose of 25 mg/kg (loose NFDC-25), 2,418 (26.6%) with a non-fixed dose combination with an AQ target dose of 30 mg/kg (loose NFDC-30), and the remaining 1,257 (13.8%) with a co-blistered non-fixed dose combination with an AQ target dose of 30 mg/kg (co-blistered NFDC). The median dose of AQ administered was 32.1 mg/kg [IQR: 25.9-38.2], the highest dose being administered to patients treated with co-blistered NFDC (median = 35.3 mg/kg [IQR: 30.6-43.7]) and the lowest to those treated with loose NFDC-25 (median = 25.0 mg/kg [IQR: 22.7-25.0]). Patients treated with FDC received a median dose of 32.4 mg/kg [IQR: 27-39.0]. After adjusting for reinfections, the corrected antimalarial efficacy on day 28 after treatment was similar for co-blistered NFDC (97.9% [95% confidence interval (CI): 97.0-98.8%]) and FDC (98.1% [95% CI: 97.6%-98.5%]; P = 0.799), but significantly lower for the loose NFDC-25 (93.4% [95% CI: 91.9%-94.9%]), and loose NFDC-30 (95.0% [95% CI: 94.1%-95.9%]) (P

Renewed global efforts toward malaria eradication have highlighted the need for novel antimalarial agents with activity against multiple stages of the parasite life cycle. We have previously reported the discovery of a novel class of antimalarial compounds in the imidazolopiperazine series that have activity in the prevention and treatment of blood stage infection in a mouse model of malaria. Consistent with the previously reported activity profile of this series, the clinical candidate KAF156 shows blood schizonticidal activity with 50% inhibitory concentrations of 6 to 17.4 nM against P. falciparum drug-sensitive and drug-resistant strains, as well as potent therapeutic activity in a mouse models of malaria with 50, 90, and 99% effective doses of 0.6, 0.9, and 1.4 mg/kg, respectively. When administered prophylactically in a sporozoite challenge mouse model, KAF156 is completely protective as a single oral dose of 10 mg/kg. Finally, KAF156 displays potent Plasmodium transmission blocking activities both in vitro and in vivo. Collectively, our data suggest that KAF156, currently under evaluation in clinical trials, has the potential to treat, prevent, and block the transmission of malaria.