Deployment and utilization of next-generation sequencing of Plasmodium falciparum to guide anti-malarial drug policy decisions in sub-Saharan Africa: opportunities and challenges.

Parasite resistance against anti-malarial drugs is a major threat to the ongoing malaria control and elimination strategies. This is especially true since resistance to the currently recommended artemisinins and partner drugs has been confirmed in South East Asia (SEA) and new anti-malarial compounds are not expected to be available in the near future. Spread from SEA or independent emergence of artemisinin resistance in sub-Saharan Africa (SSA) could reverse the achievements in malaria control that have been attained in the past two decades and derail the ongoing elimination strategies. The current surveillance of clinical efficacy and resistance to anti-malarial drugs is based on efficacy trials to assess the clinical performance of anti-malarials, in vivo/ex vivo assessment of parasite susceptibility to anti-malarials and prevalence of known molecular markers of drug resistance. Whereas clinical efficacy trials are restricted by cost and the complex logistics of patient follow-up, molecular detection of genetic mutations associated with resistance or reduced susceptibility to anti-malarials is by contrast a simple and powerful tool for early detection and monitoring of the prevalence of resistant parasites at population level. This provides needed information before clinical failure emerges, allowing policy makers to anticipate problems and respond. The various methods previously used in detection of molecular markers of drug resistance share some limitations: low-throughput, and high costs per sample and demanding infrastructure. However, recent technological advances including next-generation sequencing (NGS) methodologies promise greatly increased throughput and reduced costs, essentially providing unprecedented potential to address different research and operational questions of relevance for drug policy. This review assesses the potential role of NGS to provide comprehensive information that could guide drug policies in malaria endemic countries and looks at the foreseeable challenges facing the establishment of NGS approaches for routine surveillance of parasite resistance to anti-malarials in SSA

Fetal growth and birth weight are independently reduced by malaria infection and curable sexually transmitted and reproductive tract infections in Kenya, Tanzania, and Malawi: A pregnancy cohort study

Objective Malaria and sexually transmitted and reproductive tract infections (STIs/RTIs) are highly prevalent in sub-Saharan Africa and associated with poor pregnancy outcomes. We investigated the individual and combined effects of malaria and curable STIs/RTIs on fetal growth in Kenya, Tanzania, and Malawi. Methods This study was nested within a randomized trial comparing monthly intermittent preventive treatment for malaria in pregnancy with sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine, alone or combined with azithromycin. Fetal weight gain was assessed by serial prenatal ultrasound. Malaria was assessed monthly, and Treponema pallidum, Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis and bacterial vaginosis at enrolment and in the third trimester. The effect of malaria and STIs/RTIs on fetal weight/birthweight Z-scores was evaluated using mixed-effects linear regression. Results 1,435 pregnant women had fetal/birth weight assessed 3,950 times. Compared to women without malaria or STIs/RTIs (n=399), malaria-only (n=267), STIs/RTIs-only (n=410) or both (n=353) were associated with reduced fetal growth (adjusted mean difference in fetal/birth weight Z-score [95% CI]: malaria=-0.18 [-0.31,-0.04], p=0.01]; STIs/RTIs=-0.14 [-0.26,-0.03], p=0.01]; both=-0.20 [-0.33,-0.07], p=0.003). Paucigravidae experienced the greatest impact. Conclusion Malaria and STIs/RTIs are associated with poor fetal growth especially among paucigravidae women with dual infections. Integrated antenatal interventions are needed to reduce the burden of both malaria and STIs/RTIs

Fetal growth and birth weight are independently reduced by malaria infection and curable sexually transmitted and reproductive tract infections in Kenya, Tanzania, and Malawi: A pregnancy cohort study

Objective: Malaria and sexually transmitted and reproductive tract infections (STIs/RTIs) are highly prevalent in sub-Saharan Africa and associated with poor pregnancy outcomes. We investigated the individual and combined effects of malaria and curable STIs/RTIs on fetal growth in Kenya, Tanzania, and Malawi. Methods: This study was nested within a randomized trial comparing monthly intermittent preventive treatment for malaria in pregnancy with sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine, alone or combined with azithromycin. Fetal weight gain was assessed by serial prenatal ultrasound. Malaria was assessed monthly, and Treponema pallidum, Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis and bacterial vaginosis at enrolment and in the third trimester. The effect of malaria and STIs/RTIs on fetal weight/birthweight Z-scores was evaluated using mixed-effects linear regression. Results: 1,435 pregnant women had fetal/birth weight assessed 3,950 times. Compared to women without malaria or STIs/RTIs (n=399), malaria-only (n=267), STIs/RTIs-only (n=410) or both (n=353) were associated with reduced fetal growth (adjusted mean difference in fetal/birth weight Z-score [95% CI]: malaria=-0.18 [-0.31,-0.04], p=0.01]; STIs/RTIs=-0.14 [-0.26,-0.03], p=0.01]; both=-0.20 [-0.33,-0.07], p=0.003). Paucigravidae experienced the greatest impact. Conclusion Malaria and STIs/RTIs are associated with poor fetal growth especially among paucigravidae women with dual infections. Integrated antenatal interventions are needed to reduce the burden of both malaria and STIs/RTIs

Effect of monthly intermittent preventive treatment with dihydroartemisinin–piperaquine with and without azithromycin versus monthly sulfadoxine–pyrimethamine on adverse pregnancy outcomes in Africa: a double-blind randomised, partly placebo-controlled trial

Background Intermittent preventive treatment in pregnancy (IPTp) with dihydroartemisinin–piperaquine is more effective than IPTp with sulfadoxine–pyrimethamine at reducing malaria infection during pregnancy in areas with high-grade resistance to sulfadoxine–pyrimethamine by Plasmodium falciparum in east Africa. We aimed to assess whether IPTp with dihydroartemisinin–piperaquine, alone or combined with azithromycin, can reduce adverse pregnancy outcomes compared with IPTp with sulfadoxine–pyrimethamine. Methods We did an individually randomised, double-blind, three-arm, partly placebo-controlled trial in areas of high sulfadoxine–pyrimethamine resistance in Kenya, Malawi, and Tanzania. HIV-negative women with a viable singleton pregnancy were randomly assigned (1:1:1) by computer-generated block randomisation, stratified by site and gravidity, to receive monthly IPTp with sulfadoxine–pyrimethamine (500 mg of sulfadoxine and 25 mg of pyrimethamine for 1 day), monthly IPTp with dihydroartemisinin–piperaquine (dosed by weight; three to five tablets containing 40 mg of dihydroartemisinin and 320 mg of piperaquine once daily for 3 consecutive days) plus a single treatment course of placebo, or monthly IPTp with dihydroartemisinin–piperaquine plus a single treatment course of azithromycin (two tablets containing 500 mg once daily for 2 consecutive days). Outcome assessors in the delivery units were masked to treatment group. The composite primary endpoint was adverse pregnancy outcome, defined as fetal loss, adverse newborn baby outcomes (small for gestational age, low birthweight, or preterm), or neonatal death. The primary analysis was by modified intention to treat, consisting of all randomised participants with primary endpoint data. Women who received at least one dose of study drug were included in the safety analyses. This trial is registered with ClinicalTrials.gov, NCT03208179. Findings From March-29, 2018, to July 5, 2019, 4680 women (mean age 25·0 years [SD 6·0]) were enrolled and randomly assigned: 1561 (33%; mean age 24·9 years [SD 6·1]) to the sulfadoxine–pyrimethamine group, 1561 (33%; mean age 25·1 years [6·1]) to the dihydroartemisinin–piperaquine group, and 1558 (33%; mean age 24·9 years [6.0]) to the dihydroartemisinin–piperaquine plus azithromycin group. Compared with 335 (23·3%) of 1435 women in the sulfadoxine–pyrimethamine group, the primary composite endpoint of adverse pregnancy outcomes was reported more frequently in the dihydroartemisinin–piperaquine group (403 [27·9%] of 1442; risk ratio 1·20, 95% CI 1·06–1·36; p=0·0040) and in the dihydroartemisinin–piperaquine plus azithromycin group (396 [27·6%] of 1433; 1·16, 1·03–1·32; p=0·017). The incidence of serious adverse events was similar in mothers (sulfadoxine–pyrimethamine group 17·7 per 100 person-years, dihydroartemisinin–piperaquine group 14·8 per 100 person-years, and dihydroartemisinin–piperaquine plus azithromycin group 16·9 per 100 person-years) and infants (sulfadoxine–pyrimethamine group 49·2 per 100 person-years, dihydroartemisinin–piperaquine group 42·4 per 100 person-years, and dihydroartemisinin–piperaquine plus azithromycin group 47·8 per 100 person-years) across treatment groups. 12 (0·2%) of 6685 sulfadoxine–pyrimethamine, 19 (0·3%) of 7014 dihydroartemisinin–piperaquine, and 23 (0·3%) of 6849 dihydroartemisinin–piperaquine plus azithromycin treatment courses were vomited within 30 min. Interpretation Monthly IPTp with dihydroartemisinin–piperaquine did not improve pregnancy outcomes, and the addition of a single course of azithromycin did not enhance the effect of monthly IPTp with dihydroartemisinin–piperaquine. Trials that combine sulfadoxine–pyrimethamine and dihydroartemisinin–piperaquine for IPTp should be considered