Monthly sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine for intermittent preventive treatment of malaria in pregnancy: a double-blind, randomised, controlled, superiority trial

Coinheritance of polymorphic alleles of PIEZO1, G6PD and HBB enhances protection against malaria

Malaria has exerted potent selective pressure on the human genome over millennia and has been a significant force in shaping human evolution. We have determined in 424 individuals living in malaria-hyperendemic areas in Ghana and in the Democratic Republic of Congo, the genotypes at the loci PIEZO1, G6PD, HBB, and PKLR. By qPCR we have also estimated P. falciparum parasitemia in all these subjects. We found that 41% of individuals tested had one protective variant, 20.5% two variants, 6.4% three variants, and 0.7% four variants. We have confirmed that Pz_E756del, G6pd A-, and HbS are associated with lower parasite density. The highest allele frequency was that of Pz_E756del, approaching 0.2, and we found that it is in linkage disequilibrium with Pz_E750Q. While overall malaria prevalence did not differ significantly among the groups, non-pregnant individuals with multiple protective alleles had lower rates of high-density parasitaemia, suggesting an additive effect of these variants against severe malaria infection, while pregnancy showed different allele protection profile. The high frequency of individuals carrying two or more protective polymorphisms might have implications for malaria transmission and parasite reservoir maintenance. Thus, the significance of additive or possibly synergistic effects of multiple protective genes co-existing in the same person deserves further investigation.

Health-Related Quality of Life in Children With Sickle Cell Anemia in Malaria-Endemic Regions: The Impact of Disease States and Malaria Prevention Strategies

OBJECTIVES

To assess the health-related quality of life (HRQoL) of children with sickle cell anemia (SCA) in Uganda and Malawi during steady disease states and sick attacks and to examine the impact of malaria chemoprevention with weekly dihydroartemisinin-piperaquine compared to monthly sulfadoxine-pyrimethamine.

METHODS

This cohort study was nested within a clinical trial comparing weekly dihydroartemisinin-piperaquine with the standard of care (monthly sulfadoxine-pyrimethamine) among children with SCA. HRQoL was assessed using EQ-5D tools during steady states and sick attacks. Ordinary least squares regression identified factors associated with HRQoL.

RESULTS

A total of 633 children with SCA were enrolled (mean age 8.1 years, standard deviation [SD] 3.7). HRQoL was higher during steady states but deteriorated during sick attacks, with the most problems reported in pain and discomfort. Older children (ages 12-16: mean difference [MD] = 0.09, P < .0001) experienced higher HRQoL during steady states but lower HRQoL during sick attacks. Hospitalization negatively affected HRQoL; children hospitalized 1 to 3 times (MD = -0.27, P = .01) or ≥4 times (MD = -0.24, P = .02) had substantially lower HRQoL. There were no HRQoL differences between treatment arms.

CONCLUSIONS

The HRQoL of children with SCA was relatively high during steady states but declined substantially during sick attacks, especially because of severe pain and discomfort. HRQoL is influenced by a child's age and frequency of hospitalization. Results provide information for calculation of quality-adjusted life years for future economic evaluation.

Dihydroartemisinin-piperaquine versus sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria in pregnancy: a systematic review and individual participant data meta-analysis

Background

High-grade Plasmodium falciparum resistance to sulfadoxine-pyrimethamine in east and southern Africa has prompted trials evaluating intermittent preventive treatment in pregnancy (IPTp) with dihydroartemisinin-piperaquine as an alternative to sulfadoxine-pyrimethamine. We aimed to provide an updated and comprehensive review of trials conducted in areas of high P. falciparum resistance that compared the efficacy of two types of IPTp regimens on maternal, birth, and infant outcomes.

Methods

We conducted two-stage, individual participant data meta-analyses of randomised trials comparing IPTp with dihydroartemisinin-piperaquine to sulfadoxine-pyrimethamine on maternal, birth, and infant outcomes. We searched the WHO International Clinical Trials Registry Platform, ClinicalTrials.Gov, PubMed, and the Malaria in Pregnancy Consortium Library, on July 30, 2020 (updated on September 24, 2024), without restrictions by publication date, peer-review status, or language. Eligible trials enrolled HIV-uninfected pregnant women, followed participants to delivery, included participants with no prior IPTp use during the current pregnancy, and were conducted in areas with high-level parasite resistance to sulfadoxine-pyrimethamine (i.e., PfDHPS 540E ≥ 90% and/or 581G>0%). Only singleton pregnancies were analysed. The primary endpoint was a composite measure of any adverse pregnancy outcome defined as fetal or neonatal loss, small-for-gestational age, low birthweight, or preterm birth. Summary estimates were generated using a random-effects model. Gravidity subgroup analyses were performed. Causal mediation analyses were used to investigate the maternal mechanisms underlying the effect of IPTp regimens on birth outcomes. The meta-analysis is registered in PROSPERO (CRD42020196127).

Findings

Of 85 screened records, six trials (one multi-country trial) from Kenya, Malawi, Uganda and Tanzania contributed data on 6646 pregnancies. Compared to sulfadoxine-pyrimethamine, dihydroarteminsinin-piperaquine was associated with a 69% [95% CI: 45%-82%] lower incidence of clinical malaria during pregnancy, a 62% [37%-77%] lower risk of placental parasitaemia, and a 17% [0%-31%] lower incidence of moderate maternal anaemia. In contrast, sulfadoxine-pyrimethamine was associated with higher mean maternal weight gain (34 g/week [17-51]). There were no statistically significant differences in the composite adverse pregnancy outcome (RR = 1.05 [0.92-1.19]; I 2 = 48%). Individual components of the primary outcome showed no statistically significant differences in the risks of fetal loss (RR = 0.94 [0.61-1.46]), preterm birth (RR = 0.93 [0.76-1.14]), low birthweight (RR = 1.09 [0.83-1.43]), or neonatal loss (RR = 0.73 [0.42-1.26]), though findings may have been underpowered. Small-for-gestational-age risk was 15% (3%-24%) lower in the sulfadoxine-pyrimethamine arm, particularly among multigravidae (a 22% reduction vs 9% in primigravidae). Among multigravidae, infant stunting and underweight by two months was 20% [8%-30%] and 35% [17%-49%] lower in the sulfadoxine-pyrimethamine arm compared to dihydroartemisinin-piperaquine. Compared to dihydroartemisinin-piperaquine, sulfadoxine-pyrimethamine was associated with higher mean newborn birthweight (mean difference (MD) = 50 g [95% CI: 13-88]; p = 0.0090, I2 = 61%) and BWGA z-scores (MD = 0.12 [95% CI: 0.05-0.20]; p = 0.0012, I2 = 51%), but not gestational age at birth (MD = 0 weeks [95% CI: -0.11 to 0.12]; p = 0.94; I2 = 42%). Infant wasting by two months was 13% [3%-22%] lower in the sulfadoxine-pyrimethamine arm, regardless of gravidity. Mediation analyses indicated that 15% [0%-19%] of sulfadoxine-pyrimethamine's superior effect on small-for-gestational-age risk was mediated by its greater impact on gestational weight gain.

Interpretation

In areas with high P. falciparum sulfadoxine-pyrimethamine resistance, dihydroartemisinin-piperaquine offers superior antimalarial efficacy than sulfadoxine-pyrimethamine. However, replacing sulfadoxine-pyrimethamine with dihydroartemisinin-piperaquine alone may not lead to improved maternal and infant health outcomes. Instead, it could result in slightly reduced gestational weight gain and a modest increase in the risk of small-for-gestational age births, and poor infant growth by two months of age. Future research evaluating alternative strategies for IPTp are needed.

Funding

This work was supported by the Bill and Melinda Gates Foundation and Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Drivers of anemia reduction among women of reproductive age in Uganda: a country case study

BACKGROUND

In Uganda, anemia prevalence among women of reproductive age (WRA) decreased from 41% in 2006 to 32% in 2016. The factors associated with this reduction are uncertain.

OBJECTIVES

We conducted a systematic in-depth assessment of the quantitative and qualitative determinants of anemia among WRA in Uganda between 2006 and 2016.

METHODS

Employing standard Exemplars in Global Health methodology, quantitative analyses were conducted using Uganda's Demographic and Health Surveys. Qualitative analyses included a comprehensive literature review, program analysis, and stakeholder interviews to identify and understand country-level enablers and barriers to WRA anemia decline in Uganda over the past 2 decades. A final Oaxaca-Blinder decomposition analysis (OBDA) evaluated the relative contribution of direct and indirect factors.

RESULTS

Among nonpregnant women (NPW), mean hemoglobin (Hb) increased from 12.3 g/dL in 2006 to 12.6 g/dL in 2016 (P < 0.01), corresponding to a 9%-point decline in anemia prevalence during this time (from 40% to 31%). However, inequities by geographical region, household wealth, and women's educational attainment persisted. Key programs over the study period included food fortification, the Uganda Anemia Policy, and the Uganda Nutrition Action Plan (UNAP). Stakeholders also identified malaria control, family planning programs, and continued strengthening of Uganda's health care system as key enablers of anemia decline. Our OBDA explained 89% of the observed change in mean Hb, with family planning (27%), increased access to bednets (26%), household sociodemographics (17%), and improvement in women's overall nutrition (body mass index [BMI]: 15%) emerging as the most critical drivers of anemia decline among NPW in Uganda, corroborating our qualitative and policy analyses.

CONCLUSIONS

To protect the hard-fought gains and continue improvements, WRA anemia prevention efforts in Uganda should remain focused on improving health care access especially within antenatal care and malaria control programs. Additionally, multisectoral collaborations and investments to empower women and poverty alleviation strategies need to be enhanced.

Decreased dihydroartemisinin-piperaquine protection against recurrent malaria associated with Plasmodium falciparum plasmepsin 3 copy number variation in Africa

Dihydroartemisinin-piperaquine (DHA-PPQ) is being recommended in Africa for the management of uncomplicated Plasmodium falciparum malaria and for chemoprevention strategies, based on the ability of piperaquine to delay re-infections. Although therapeutic resistance to piperaquine has been linked to increased copy number in plasmepsin-coding parasite genes (pfpm), their effect on the duration of the post-treatment prophylactic period remains unclear. Here, we retrospectively analyzed data from a randomized clinical trial, where patients received either DHA-PPQ or artesunate-amodiaquine for recurrent malaria episodes over two years. We observed an increase in the relative risk of re-infection among patients receiving DHA-PPQ compared to artesunate-amodiaquine after the first malaria season. This was driven by shorter average times to reinfection and coincided with an increased frequency of infections comprising pfpm3 multi-copy parasites. The decline in post-treatment protection of DHA-PPQ upon repeated use in a high transmission setting raises concerns for its wider use for chemopreventive strategies in Africa.

Pregnant women as a sentinel population for genomic surveillance of malaria in the Democratic Republic of the Congo: a population-based study

BACKGROUND

Genomic surveillance is a valuable tool for detecting changes in the drug susceptibility of malaria parasites, enabling timely adjustments to treatment strategies. However, implementation can be costly and challenging in high-burden countries, especially when targeting cohorts of children. To address these challenges, we investigated whether in the Democratic Republic of the Congo pregnant women attending antenatal care services could act as an effective sentinel population for children in the same area.

METHODS

This population-based study aimed to target pregnant women in Kinshasa (Democratic Republic of the Congo), regardless of age, trimester of pregnancy, parity, or previous antenatal care centre attendance, and children younger than 14 years living in the same area. Women were invited to participate and enrolled during their routine antenatal care visit. For children, we originally planned to conduct standard school-based surveys, but implementation was affected by the COVID-19 pandemic and subsequent vaccination campaign. Therefore, we adopted an alternative approach, setting up screening posts in existing health centres and, with the support of community health workers, encouraging families to visit the posts at their convenience. The study was done in two areas of Kinshasa, urban (Binza) and semirural (Maluku), where malaria transmission is endemic and perennial. Blood samples from malaria-positive cases were genotyped using an amplicon sequencing platform, to allow comparisons of Plasmodium falciparum genomes between the two cohorts and estimations of drug resistance mutation prevalence. The study is registered with ClinicalTrials.gov, NCT05072613.

FINDINGS

Between Nov 11, 2021, and June 21, 2023, 2794 children and 4001 pregnant women were recruited to the study. Malaria prevalence by rapid diagnostic test was 49·0% (95% CI 47·1-50·8) in children and 19·1% (17·9-20·3) in pregnant women. Parasite populations sampled from the two cohorts showed highly similar allele frequencies at all tested loci, including drug resistance markers potentially under selection. Pregnant women did not have higher frequencies of sulfadoxine-pyrimethamine resistant haplotypes, which undermine preventive treatments, than children and we did not find any kelch13 mutations at significant frequency. Although parasite densities were lower in pregnant women, the complexity of infection was similar to that in children. We found no evidence of Plasmodium vivax infections in the study.

INTERPRETATION

A cohort of pregnant women produced highly similar results for antimalarial drug resistance surveillance as a cohort of children from the same area, through implementation of simple and efficient genomic surveillance systems integrated into routine antenatal care activities, while benefiting women with diagnosis and treatment.

FUNDING

Bill & Melinda Gates Foundation and Wellcome Trust.

Intermittent screening using ultra-sensitive malaria rapid diagnostic test and treatment with pyronaridine-artesunate compared to standard preventive treatment with sulfadoxine-pyrimethamine for malaria prevention in pregnant women in Kinshasa, DRC

BACKGROUND

The declining effectiveness of Intermittent Preventive Treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) due to the emergence of Plasmodium falciparum resistance highlights the need for alternative malaria prevention strategies in pregnant women. A novel approach was proposed: screening with an ultra-sensitive rapid diagnostic test and treating positive with pyronaridine-artesunate (ISTp-uRDT-PA). This trial compared the impact of both strategies on maternal malaria and anaemia, abortion, intrauterine death, birth weight, preterm delivery.

METHODS

This non-inferiority trial, conducted in Kinshasa, enrolled pregnant women in their second and third trimesters. Participants in the IPTp-SP arm (n = 124) received SP at monthly antenatal visit as per guidelines, while those in the ISTp-uRDT-PA arm (n = 126) were screened monthly with an uRDT and treated with PA if positive. Primary outcomes included asymptomatic parasitaemia (uRDT positive without fever) or symptomatic parasitaemia (uRDT positive with fever or history of fever, and parasite density by microscopy during pregnancy.

RESULTS

Asymptomatic parasitaemia by uRDT during pregnancy was similar in both arms (20.8% in IPTp-SP vs 21.0% in ISTp-uRDT-PA). At delivery, asymptomatic parasitaemia was 51% higher in ISTp-uRDT-PA arm compared to IPTp-SP (cRR = 1.51 [95% CI 0.76-3.00], p = 0.24). Symptomatic parasitaemia by uRDT at delivery showed no significant difference. Malaria by microscopy at enrolment was detected in 34.4% of women. Malaria by microscopy during pregnancy was 9.6% in IPTp-SP and 10.1%. ISTp-uRDT-PA (p = 0.19), decreasing to 3.2% and 0.9%, respectively, at delivery (p = 0.24). Mean haemoglobin concentration at enrolment was 10.1 g/dl in the IPTp-SP and 9.8 g/dl in the ISTp-uRDT-PA with no significant difference in maternal anaemia at delivery (7%; cRR = 1.07 [95% CI 0.87-1.31], p = 0.52). No significant differences were found for spontaneous abortions and in utero death in both arms. The risk of a premature newborn declined by 14% in ISTp-uRDT-PA compared to the IPTp-SP arm (cRR = 0.86 [95% CI 0.29-2.85], p = 0.79) while low-birth-weight was not significantly higher (cRR = 1.74 [95% CI 0.86-3.53], p = 0.12).

CONCLUSION

ISTp-uRDT-PA was non inferior to IPTp-SP and can be considered as a future alternative for IPTp-SP in case this intervention can no longer be used due to high SP resistance.

CLINICAL TRIALS REGISTRATION

NCT04783051.

Drug-Drug Interaction Between Dihydroartemisinin-Piperaquine and Sulfadoxine-Pyrimethamine During Malaria Chemoprevention in Pregnant Women

Co-administration of dihydroartemisinin-piperaquine (DP) and sulfadoxine-pyrimethamine (SP) for intermittent preventive treatment of malaria in pregnancy (IPTp) may be superior in preventing adverse birth outcomes compared with either therapy alone, but potential drug-drug interactions require investigation. We conducted intensive and sparse pharmacokinetic (PK) studies in a subset of Ugandan women participating in a randomized controlled trial of monthly IPTp with SP vs. DP vs. DP + SP. Intensive PK sampling was performed from day 0 to 23 after dosing at 28 weeks gestation in 87 participants across treatment arms. Sparse sampling was performed on day 28 (trough) after dosing at 20 and 28 gestational weeks in additional 196 participants receiving SP vs. DP + SP. Intensive PK analysis demonstrated that compared with SP alone, co-administration of DP + SP was associated with lower maximal concentrations, the area under the concentration-time curves (AUC), and day 23 concentrations of sulfadoxine (25%, 25%, and 27%) and pyrimethamine (26%, 34%, and 32%) (P < 0.05 for all comparisons). Sparse PK results demonstrated participants co-administered DP + SP had lower trough concentrations after dosing at 20 and 28 gestational weeks for sulfadoxine (6%, P = 0.68 and 31%, P = 0.023, respectively) and pyrimethamine (18%, P = 0.032 and 33%, P < 0.001, respectively) compared with SP alone. Co-administration of DP + SP was associated with a 19% reduction in piperaquine AUC (P = 0.046), but no significant difference in other PK parameters compared with DP alone. In summary, co-administration of DP + SP was associated with significantly reduced SP exposure, with a greater magnitude during the third vs. second trimester. The clinical consequences of this interaction are yet unknown.

Acceptability of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine plus dihydroartemisinin-piperaquine in Papua New Guinea: a qualitative study

BACKGROUND

In moderate-to-high malaria transmission regions, the World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) alongside insecticide-treated bed nets to reduce the adverse consequences of pregnancy-associated malaria. Due to high-grade Plasmodium falciparum resistance to SP, novel treatment regimens need to be evaluated for IPTp, but these increase pill burden and treatment days. The present qualitative study assessed the acceptability of IPTp-SP plus dihydroartemisinin-piperaquine (DP) in Papua New Guinea, where IPTp-SP was implemented in 2009.

METHODS

Individual in-depth interviews (IDIs) and focus group discussions were conducted at health facilities where a clinical trial evaluated IPTp-SP plus DP (three-day regimen) versus IPTp-SP plus DP-placebo. IDIs were conducted with: (1) trial participants at different stages of engagement with ANC and IPTp, e.g. first antenatal clinic visit, subsequent antenatal clinic visits and postpartum; (2) local health workers (nurses, community health workers, midwives, health extension officers, doctors); and (3) representatives of district, provincial and national health authorities involved in programming ANC and IPTp. Focus group discussions comprised pregnant women only, including those engaged in the clinical trial and those receiving routine ANC outside of the trial. All interviews were audio recorded and transcribed. Transcripts were analysed using inductive and deductive thematic analysis applying a framework assessing: affective attitude, burden, ethicality, intervention coherence, opportunity costs, perceived effectiveness, and self-efficacy.

RESULTS

Women expressed positive feelings and attitudes towards SP plus DP/DP-placebo; reported limited side effects; and found the size, number, colour, and taste of study medicines acceptable. Health workers and policymakers were concerned that, compared to SP alone, additional tablets, frequency (three-day regimen), and tablet size might be barriers to acceptability for users outside a non-trial setting. There was a high perceived effectiveness of SP plus DP; most women reported that they did not get malaria or felt sick during pregnancy. Broader healthcare benefits received through trial participation and the involvement of health workers, relatives and community members in the clinical trial enabled antenatal clinic attendance and perceived acceptability of this IPTp regimen.

CONCLUSIONS

In the trial context, IPTp-SP plus DP was acceptable to both users and providers. Healthcare providers were concerned about the realities of acceptability and adherence to SP plus DP outside a clinical trial setting.

Malaria vaccines: a new era of prevention and control

Malaria killed over 600,000 people in 2022, a death toll that has not improved since 2015. Additionally, parasites and mosquitoes resistant to existing interventions are spreading across Africa and other regions. Vaccines offer hope to reduce the mortality burden: the first licensed malaria vaccines, RTS,S and R21, will be widely deployed in 2024 and should substantially reduce childhood deaths. In this Review, we provide an overview of the malaria problem and the Plasmodium parasite, then describe the RTS,S and R21 vaccines (the first vaccines for any human parasitic disease), summarizing their benefits and limitations. We explore next-generation vaccines designed using new knowledge of malaria pathogenesis and protective immunity, which incorporate antigens and platforms to elicit effective immune responses against different parasite stages in human or mosquito hosts. We describe a decision-making process that prioritizes malaria vaccine candidates for development in a resource-constrained environment. Future vaccines might improve upon the protective efficacy of RTS,S or R21 for children, or address the wider malaria scourge by preventing pregnancy malaria, reducing the burden of Plasmodium vivax or accelerating malaria elimination.

"If they take it without knowing, they will default…": perceptions of targeted information transfer to promote adherence to intermittent preventive treatment with dihydroartemisinin-piperaquine for the prevention of malaria in pregnancy in western Kenya

BACKGROUND

Increasing resistance to sulfadoxine-pyrimethamine (SP) threatens the effectiveness of intermittent preventive treatment (IPTp) to prevent malaria in pregnancy. Dihydroartemisinin-piperaquine (DP) is the most promising candidate to emerge from clinical trials, but requires a multi-day regimen. Despite being a single-dose regimen, coverage of IPTp-SP remains low, fuelling concerns about adherence to multi-day drug options. An implementation feasibility trial in routine antenatal care settings in western Kenya demonstrated that adherence to the multi-day DP regimen was improved when IPTp-DP was delivered with a targeted information transfer intervention that comprised healthcare provider training and communication tools to support delivery and uptake. This study explored healthcare provider and pregnant women perspectives to understand (1) how the targeted information transfer improved adherence to IPTp-DP and (2) if improved adherence to IPTp-DP influenced provider perceptions towards implementation feasibility of multi-day drug regimens for IPTp.

METHODS

In-depth interviews were conducted with 64 healthcare providers and 64 pregnant women, selected using a convenience sampling approach from across the three trial arms: IPTp-DP+ (with intervention), IPTp-DP, and current standard of care IPTp-SP. Transcripts from healthcare providers and pregnant women were coded in Nvivo-12 using separate a priori frameworks that included components of the consolidated framework for implementation research. Thematic analysis was used to understand how the targeted information transfer affected adherence to IPTp-DP and how concerns about adherence might influence provider perceptions towards multi-day drug regimens for IPTp.

RESULTS

Adherence to IPTp-DP doses taken at home was compromised when women experienced unpleasant side effects. Pregnant women valued being given information about IPTp-DP, including potential side effects and how to manage them. Among providers in the IPTp-DP + arm, confidence in advising women on how to manage side effects increased, and they believed this guidance improved adherence. When concerns about adherence were reduced, providers in the IPTp-DP + arm were positive about implementation feasibility, whereas providers in the IPTp-SP arm remained focused on the dosing complexities and were less convinced of the feasibility of implementing IPTp-DP.

CONCLUSIONS

Healthcare provider confidence in advising women on how to minimize side effects was boosted through targeted information transfer, which was perceived to improve adherence to IPTp-DP. Policy makers are encouraged to consider supportive interventions that enhance provider confidence around adherence should they shift to multi-day drug regimens for IPTp.

Dihydroartemisinin-piperaquine versus sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria in pregnancy: a systematic review and individual participant data meta-analysis

Background

High-grade Plasmodium falciparum resistance to sulfadoxine-pyrimethamine in East and Southern Africa has prompted numerous trials evaluating intermittent preventive treatment in pregnancy (IPTp) with dihydroartemisinin-piperaquine as an alternative to sulfadoxine-pyrimethamine.

Methods

We conducted individual participant data meta-analyses of randomised trials comparing IPTp with dihydroartemisinin-piperaquine to sulfadoxine-pyrimethamine on maternal, birth, and infant outcomes. We searched the WHO International Clinical Trials Registry Platform, ClinicalTrials.Gov, PubMed, and the Malaria in Pregnancy Consortium Library. Eligible trials enrolled HIV-uninfected pregnant women, followed participants to delivery, included participants with no prior IPTp use during the current pregnancy, and were conducted in areas with high-level parasite resistance to sulfadoxine-pyrimethamine (i.e., PfDHPS 540E≥90% and/or 581G>0%). Only singleton pregnancies were analysed. Meta-analyses used a two-stage approach: first, study-specific estimates were generated and then pooled using a random-effects model. Gravidity subgroup analyses were performed. Causal mediation analyses were used to investigate the maternal mechanisms underlying the effect of IPTp regimens on birth outcomes. The meta-analysis is registered in PROSPERO (CRD42020196127).

Findings

Of 85 screened records, six trials (one multi-country trial) contributed data on 6646 pregnancies. Compared to sulfadoxine-pyrimethamine, dihydroarteminsinin-piperaquine was associated with a 69% [95% CI: 45%-82%] lower incidence of clinical malaria during pregnancy, a 62% [37%-77%] lower risk of placental parasitaemia, and a 17% [0%-31%] lower incidence of moderate maternal anaemia (Hb<9 g/dL). In contrast, sulfadoxine-pyrimethamine was associated with higher mean weekly maternal weight gain (34 grams/week [17-51]). There were no statistically significant differences in the composite adverse pregnancy outcome between the two IPTp regimens (RR=1·05 [95% CI: 0·92-1·19]; I 2=48%), although the risk of small-for-gestational-age was 15% [3%-24%] lower in the sulfadoxine-pyrimethamine arm. Among multigravidae, participants of the sulfadoxine-pyrimethamine arm were 20% [8%-30%] and 35% [17%-49%] less likely to have stunted and underweight infants by two months compared to the dihydroartemisinin-piperaquine arm. Infant wasting by two months was 13% [3%-22%] lower in the sulfadoxine-pyrimethamine arm, regardless of gravidity. Mediation analyses indicated that 15% [0%-19%] of sulfadoxine-pyrimethamine's superior effect on reducing small-for-gestational-age risk was mediated by its greater impact on gestational weight gain.

Interpretation

In areas of high P. falciparum sulfadoxine-pyrimethamine resistance, dihydroartemisin-inpiperaquine is a more efficacious antimalarial than sulfadoxine-pyrimethamine. However, replacing sulfadoxine-pyrimethamine with dihydroartemisinin-piperaquine alone will not result in better maternal, birth, or infant outcomes. It could increase the risk of SGA, since much of the effect of sulfadoxine-pyrimethamine may be exerted through non-malarial mechanisms. Future research evaluating the alternative strategies for IPTp are needed, including with the combination of sulfadoxine-pyrimethamine and dihydroartemisinin-piperaquine.

Funding

This work was supported by the Bill and Melinda Gates Foundation and Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Dihydroartemisinin-Piperaquine Combination in the Treatment of Uncomplicated Plasmodium falciparum Malaria: Update on Clinical Failures in Africa and Tools for Surveillance

Dihydroartemisinin (or artenimol)-piperaquine is one of the six artemisinin-based combination therapies recommended in uncomplicated malaria treatment. However, artemisinin partial resistance has been reported in Cambodia, Laos, Vietnam, India, and, recently, in Africa. Polymorphisms in the Pfk13 gene have been described as molecular markers of artemisinin resistance and the amplification of the plasmepsine II/III (Pfpmp2/Pfpmp3) gene has been associated with piperaquine resistance. However, some therapeutic failures with this combination remain unexplained by strains' characterization. We provide an overview on the use of dihydroartemisinin-piperaquine in malaria treatment and discuss tools available to monitor its efficacy.

Intermittent preventive treatment for malaria in pregnancy and infant growth: a mediation analysis of a randomised trial

BACKGROUND

Intermittent preventive treatment for malaria in pregnancy (IPTp) can improve birth outcomes, but whether it confers benefits to postnatal growth is unclear. We investigated the effect of IPTp on infant growth in Uganda and its pathways of effects using causal mediation analyses.

METHODS

We analysed data from 633 infants born to mothers enrolled in a randomised trial of monthly IPTp with dihydroartemisinin-piperaquine (DP) vs. sulfadoxine-pyrimethamine (SP) (NCT02793622). Weight and length were measured from 0 to 12 months of age. Using generalised linear models, we estimated effects of DP vs. SP on gravidity-stratified mean length-for-age (LAZ) and weight-for-length Z-scores (WLZ). We investigated mediation by placental malaria, gestational weight change, maternal anaemia, maternal inflammation-related proteins, preterm birth, birth length, and birth weight. Mediation models adjusted for infant sex, gravidity, gestational age at enrolment, maternal age, maternal parasitaemia at enrolment, education, and wealth.

FINDINGS

SP increased mean LAZ by 0.18-0.28 Z from birth through age 4 months compared to DP, while DP increased mean WLZ by 0.11-0.28 Z from 2 to 8 months compared to SP among infants of multigravidae; at these ages, confidence intervals for mean differences excluded 0. We did not observe differences among primigravida. Mediators of SP included birth weight, birth length, maternal stem cell factor, and DNER. Mediators of DP included placental malaria and birth length, maternal IL-18, CDCP1, and CD6 at delivery.

INTERPRETATION

In high malaria transmission settings, this exploratory study suggests different IPTp regimens may influence infant growth among multigravidae, potentially through distinct pathways, in the exclusive breastfeeding period, when few other interventions are available.

FUNDING

Stanford Center for Innovation in Global Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bill & Melinda Gates Foundation.

ONT sequencing identifies a high prevalence of crt sensitive, triple mutant dhfr and single mutant dhps parasites within an ANC population in Nigeria

Background

Malaria in pregnancy is a major public health issue, particularly among vulnerable populations in malaria-endemic sub-Saharan African countries. To mitigate its risks, WHO recommends sulphadoxine-pyrimethamine (SP) for chemoprevention and artemisinin-based combination therapy (ACT) to treat uncomplicated Plasmodium falciparum malaria. These interventions have helped to alleviate the risk associated with malaria in pregnancy; however, in the context of the emergence of SP- and ACT-resistant P. falciparum, maintained efficacy is under threat. Molecular surveillance is a reliable tool to monitor the emergence of resistance where molecular markers are known. Thus, the objective of the study was to use a multiplexed amplicon Oxford Nanopore sequencing approach to assess the molecular markers for antimalarial resistance among pregnant women in Nigeria.

Methods

Dried blood spots (DBS) were collected from pregnant women who received IPTp-SP at the enrollment and follow-up visits. P. falciparum genomic DNA was extracted by the Chelex® method and Pf18S qPCR was used to detect parasite DNA in each sample. With nested PCR assays, fragments of Pfdhps, Pfdhfr, Pfmdr1, Pfcrt, Pfk13 and Pfama1 genes were amplified and multiplexed amplicon-based sequencing was conducted on the minION Oxford Nanopore Technology.

Result

In total, 251 pregnant women were enrolled in the study and 457 DBS samples were collected. P. falciparum genomic DNA was detected in 12% (56/457) of the samples, 31 at baseline and the remaining during the follow-up visits. Pfama1, pfk13, Pfdhps, Pfdhfr, Pfmdr1 and Pfcrt were successfully sequenced in a single run. Notably, k13 artemisinin resistance mutations were absent, the frequencies of Pfdhfr and Pfdhps SP resistance haplotypes, IRN for pyrimethamine resistance and ISGKA/IAGKA associated with sulphadoxine resistance were 82% (36/44) and 64% (27/42), respectively, and the Pfcrt CVIET resistant haplotype was at approximately 22% (7/32).

Conclusion and recommendations

Here a multiplexed amplicon-based ONT assay established that triple mutant Pfdfhr-IRN, double mutant Pfdhps-SG haplotypes and the chloroquine sensitive strain were prevalent among pregnant women in Nigeria.

Delivery effectiveness of and adherence to intermittent preventive treatment for malaria in pregnancy with dihydroartemisinin-piperaquine with or without targeted information transfer or sulfadoxine-pyrimethamine in western Kenya: a three-armed, pragmatic, open-label, cluster-randomised trial

BACKGROUND

High-level resistance to sulfadoxine-pyrimethamine threatens the efficacy of WHO-recommended intermittent preventive treatment in pregnancy (IPTp) with single-dose sulfadoxine-pyrimethamine to prevent malaria. Monthly IPTp with dihydroartemisinin-piperaquine, a 3-day regimen, is an emerging alternative, but this regimen poses potential implementation and adherence challenges. We aimed to assess adherence to a multiday IPTp with dihydroartemisinin-piperaquine regimen and its delivery effectiveness in routine antenatal care settings in western Kenya.

METHODS

We conducted a pragmatic, three-armed, open-label, cluster-randomised trial in antenatal clinics in 18 health-care facilities (six facilities per group) in Kisumu County and Homa Bay County in western Kenya. Clusters were facilities offering routine antenatal care services provided by trained Ministry of Health staff with 100 or more antenatal clinic attendances per month between July, 2018, and June, 2019. Private or mission hospitals, dispensaries, referral hospitals, and trial sites were excluded. Individuals in their first trimester, living with HIV, or who were not attending a scheduled antenatal clinic visit were excluded. The 18 antenatal clinics were grouped into matched triplets stratified by location and clinics in each matched triplet were randomly assigned to one of the three study groups (1:1:1). Masking was not possible. Two groups were given IPTp with dihydroartemisinin-piperaquine (one group with a targeted information transfer intervention and one group without any additional interventions) and one group was given the standard of care (ie, IPTp with sulfadoxine-pyrimethamine). The primary endpoint, adherence, was defined as the proportion of participants completing their most recent 3-day IPTp with dihydroartemisinin-piperaquine regimen. This completion was verified by pill counts during home visits no more than 2 days after participants' 3-day regimens ended. The secondary endpoint, delivery effectiveness, was defined as the proportion of participants who received the correct number of IPTp tablets and correctly repeated dosing instructions (ie, correctly recalled the instructions they received about self-administered dihydroartemisinin-piperaquine doses and the number of sulfadoxine-pyrimethamine tablets they had received) at their exit from the antenatal clinic. Individuals receiving treatment for malaria, visiting a clinic for registration only, or interviewed during IPTp drug stock-outs were excluded from analyses. We used generalised linear mixed models to compare endpoints among the IPTp with dihydroartemisinin-piperaquine groups. This trial was registered with ClinicalTrials.gov, NCT04160026, and is complete.

FINDINGS

15 facilities (five per group) completed the trial, with 1189 participants having exit interviews (377 in the IPTp with sulfadoxine-pyrimethamine group, 408 in the IPTp with dihydroartemisinin-piperaquine only group, and 404 in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group) and 586 participants having home visits (267 in the IPTp with dihydroartemisinin-piperaquine only group and 319 in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group) from Sept 8 to Dec 10, 2020. Relative to the IPTp with dihydroartemisinin-piperaquine only group, adherence was 16% higher in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group (266 [83%] of 319 participants vs 196 [73%] of 267 participants; adjusted relative risk [RR] 1·16, 95% CI 1·03-1·31; p=0·0140). Delivery effectiveness in the IPTp with dihydroartemisinin-piperaquine plus targeted information transfer intervention group was not significantly different from that in the IPTp with sulfadoxine-pyrimethamine group (352 [87%] of 403 participants vs 335 [89%] of 375 participants; adjusted RR 0·97, 95% CI 0·90-1·05; p=0·4810). However, delivery effectiveness in the IPTp with dihydroartemisinin-piperaquine only group was significantly lower than in the IPTp with sulfadoxine-pyrimethamine group (300 [74%] of 404 participants vs 335 [89%] of 375 participants; 0·84, 0·75-0·95; p=0·0030).

INTERPRETATION

Targeted information transfer interventions to health-care providers and pregnant individuals boost antenatal care delivery adherence to a multiday regimen with dihydroartemisinin-piperaquine.

FUNDING

European and Developing Countries Clinical Trials Partnership 2, UK Joint Global Health Trials Scheme of the Foreign, Commonwealth and Development Office, Medical Research Council, National Institute for Health and Care Research, and Wellcome Trust; and Swedish International Development Cooperation Agency.

Pharmacokinetics of piperaquine and its association with intermittent malaria preventive therapy outcomes during pregnancy

BACKGROUND

Dihydroartemisinin-piperaquine (DHP) recently showed superior effectiveness over sulfadoxine-pyrimethamine for malaria intermittent preventive treatment in pregnancy (IPTp). We investigated day 7 piperaquine pharmacokinetics and its therapeutic efficacy in preventing malaria during pregnancy.

METHODS

Malaria-free (mRDT) pregnant women (n = 400) who received monthly IPTp-DHP were enrolled and followed till delivery. Day 7 Plasma piperaquine concentrations were determined after each IPTp dose using UPLC/MS/MS. IPTp outcomes (symptomatic malaria and parasitemia during pregnancy, placental malaria, and maternal malaria at delivery) were monitored. Linear mixed model and Cox regression were used to assess predictors of day 7 piperaquine concentration and treatment outcome, respectively.

RESULTS

The incidences of symptomatic malaria and parasitemia during pregnancy per 100 person-year at risk were 2 and 33, respectively. The prevalence of histopathologically confirmed placental malaria and maternal malaria at delivery were 3% and 9.8%, respectively. Repeated monthly IPTp-DHP resulted in significantly increased day 7 plasma piperaquine concentration (p < 0.001). Following the 1st, 2nd, and 3rd monthly IPTp-DHP doses, the proportions of women with day 7 piperaquine concentration below the therapeutic threshold (< 30 ng/mL) were 6.1%, 4.1% and 3.6%, respectively. Factors such as maternal age, body weight and trimester were not significant predictors of day 7 piperaquine concentration. However, having a low day 7 piperaquine plasma concentration (< 30 ng/mL) was significantly associated with a higher risk of parasitemia during pregnancy (p = 0.004).

CONCLUSION

Lower day 7 piperaquine plasma concentration is a risk factor for parasitemia during pregnancy. Single plasma sampling at day 7 can be used to monitor piperaquine effectiveness during IPTp-DHP.

TRIAL REGISTRATION

Registered 09/12/2016, PACTR201612001901313.

Pathways through which intermittent preventive treatment for malaria in pregnancy influences child growth faltering: a mediation analysis

Background

Intermittent preventive treatment for malaria in pregnancy (IPTp) can improve birth outcomes, but whether it confers benefits to postnatal growth is unclear. We investigated the effect of IPTp on infant growth in Uganda and its pathways of effects using causal mediation analyses.

Methods

We analyzed data from 633 infants born to mothers enrolled in a randomized trial of monthly IPTp with dihydroartemisinin-piperaquine (DP) vs sulfadoxine-pyrimethamine (SP) (NCT02793622). Weight and length were measured from 0-12 months of age. Using generalized linear models, we estimated effects of DP vs. SP on gravidity-stratified mean length-for-age (LAZ) and weight-for-length Z-scores (WLZ). We investigated mediation by placental malaria, gestational weight change, maternal anemia, maternal inflammation-related proteins, preterm birth, birth length, and birth weight. Mediation models adjusted for infant sex, gravidity, gestational age at enrollment, maternal age, maternal parasitemia at enrollment, education, and wealth.

Findings

SP increased LAZ by 0.18-0.28 Z from birth through age 4 months compared to DP, while DP increased WLZ by 0.11-0.28 Z from 2-8 months compared to SP among infants of multigravidae. We did not observe these differences among primigravida. Mediators of SP included increased birth weight and length and maternal stem cell factor at delivery. Mediators of DP included placental malaria and birth length, maternal IL-18, CDCP1, and CD6 at delivery.

Interpretation

In high malaria transmission settings, different IPTp regimens influenced infant growth among multigravidae through distinct pathways in the period of exclusive breastfeeding, when few other interventions are available.

Funding

Stanford Center for Innovation and Global Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bill & Melinda Gates Foundation.

Sustained clinical benefit of malaria chemoprevention with sulfadoxine-pyrimethamine (SP) in pregnant women in a region with high SP resistance markers

OBJECTIVE

The effectiveness of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) is threatened by increasing SP-resistance in Africa. We assessed the level of SP-resistance markers, and the clinical and parasitological effectiveness of IPTp-SP in southern Mozambique.

METHODS

P. falciparum infection, antimalarial antibodies and dhfr/dhps SP-resistance mutants were detected by quantitative polymerase chain reaction (qPCR), suspension array technology and targeted deep sequencing, respectively, among 4016 HIV-negative women in Maputo province (2016-2019). Univariate and multivariate regression models were used to assess the association between taking the recommended three or more IPTp-SP doses (IPTp3+) and parasitological and clinical outcomes.

RESULTS

84.3% (3385/4016) women received three or more IPTp-SP doses. The prevalence of quintuple mutants at first antenatal care (ANC) visit was 94.2%. IPTp3+ was associated with a higher clearance rate of qPCR-detected infections from first ANC visit to delivery (adjusted odds ratio [aOR]=5.9, 95% CI: 1.5-33.3; p = 0.012), lower seroprevalence at delivery of antibodies against the pregnancy-specific antigen VAR2CSADBL34 (aOR=0.72, 95% CI: 0.54-0.95; p = 0.022), and lower prevalence of low birth weight deliveries (aOR: 0.61, 95% CI: 0.41-0.90; p = 0.013).

CONCLUSION

A sustained parasitological effect of IPTp-SP contributes to the clinical effectiveness of IPTp3+ in areas with high prevalence of SP-resistance markers.

Monthly Sulfadoxine-Pyrimethamine During Pregnancy Prevents Febrile Respiratory Illnesses: A Secondary Analysis of a Malaria Chemoprevention Trial in Uganda

Background

Trials evaluating antimalarials for intermittent preventive treatment in pregnancy (IPTp) have shown that dihydroartemisinin-piperaquine (DP) is a more efficacious antimalarial than sulfadoxine-pyrimethamine (SP); however, SP is associated with higher birthweight, suggesting that SP demonstrates "nonmalarial" effects. Chemoprevention of nonmalarial febrile illnesses (NMFIs) was explored as a possible mechanism.

Methods

In this secondary analysis, we leveraged data from 654 pregnant Ugandan women without HIV infection who participated in a randomized controlled trial comparing monthly IPTp-SP with IPTp-DP. Women were enrolled between 12 and 20 gestational weeks and followed through delivery. NMFIs were measured by active and passive surveillance and defined by the absence of malaria parasitemia. We quantified associations among IPTp regimens, incident NMFIs, antibiotic prescriptions, and birthweight.

Results

Mean "birthweight for gestational age" Z scores were 0.189 points (95% CI, .045-.333) higher in women randomized to IPTp-SP vs IPTp-DP. Women randomized to IPTp-SP had fewer incident NMFIs (incidence rate ratio, 0.74; 95% CI, .58-.95), mainly respiratory NMFIs (incidence rate ratio, 0.69; 95% CI, .48-1.00), vs IPTp-DP. Counterintuitively, respiratory NMFI incidence was positively correlated with birthweight in multigravidae. In total 75% of respiratory NMFIs were treated with antibiotics. Although overall antibiotic prescriptions were similar between arms, for each antibiotic prescribed, "birthweight for gestational age" Z scores increased by 0.038 points (95% CI, .001-.074).

Conclusions

Monthly IPTp-SP was associated with reduced respiratory NMFI incidence, revealing a potential nonmalarial mechanism of SP and supporting current World Health Organization recommendations for IPTp-SP, even in areas with high-grade SP resistance. While maternal respiratory NMFIs are known risk factors of lower birthweight, most women in our study were presumptively treated with antibiotics, masking the potential benefit of SP on birthweight mediated through preventing respiratory NMFIs.

Chemoprevention for malaria with monthly intermittent preventive treatment with dihydroartemisinin-piperaquine in pregnant women living with HIV on daily co-trimoxazole in Kenya and Malawi: a randomised, double-blind, placebo-controlled trial

BACKGROUND

The efficacy of daily co-trimoxazole, an antifolate used for malaria chemoprevention in pregnant women living with HIV, is threatened by cross-resistance of Plasmodium falciparum to the antifolate sulfadoxine-pyrimethamine. We assessed whether addition of monthly dihydroartemisinin-piperaquine to daily co-trimoxazole is more effective at preventing malaria infection than monthly placebo plus daily co-trimoxazole in pregnant women living with HIV.

METHODS

We did an individually randomised, two-arm, placebo-controlled trial in areas with high-grade sulfadoxine-pyrimethamine resistance in Kenya and Malawi. Pregnant women living with HIV on dolutegravir-based combination antiretroviral therapy (cART) who had singleton pregnancies between 16 weeks' and 28 weeks' gestation were randomly assigned (1:1) by computer-generated block randomisation, stratified by site and HIV status (known positive vs newly diagnosed), to daily co-trimoxazole plus monthly dihydroartemisinin-piperaquine (three tablets of 40 mg dihydroartemisinin and 320 mg piperaquine given daily for 3 days) or daily co-trimoxazole plus monthly placebo. Daily co-trimoxazole consisted of one tablet of 160 mg sulfamethoxazole and 800 mg trimethoprim. The primary endpoint was the incidence of Plasmodium infection detected in the peripheral (maternal) or placental (maternal) blood or tissue by PCR, microscopy, rapid diagnostic test, or placental histology (active infection) from 2 weeks after the first dose of dihydroartemisinin-piperaquine or placebo to delivery. Log-binomial regression was used for binary outcomes, and Poisson regression for count outcomes. The primary analysis was by modified intention to treat, consisting of all randomised eligible participants with primary endpoint data. The safety analysis included all women who received at least one dose of study drug. All investigators, laboratory staff, data analysts, and participants were masked to treatment assignment. This trial is registered with ClinicalTrials.gov, NCT04158713.

FINDINGS

From Nov 11, 2019, to Aug 3, 2021, 904 women were enrolled and randomly assigned to co-trimoxazole plus dihydroartemisinin-piperaquine (n=448) or co-trimoxazole plus placebo (n=456), of whom 895 (99%) contributed to the primary analysis (co-trimoxazole plus dihydroartemisinin-piperaquine, n=443; co-trimoxazole plus placebo, n=452). The cumulative risk of any malaria infection during pregnancy or delivery was lower in the co-trimoxazole plus dihydroartemisinin-piperaquine group than in the co-trimoxazole plus placebo group (31 [7%] of 443 women vs 70 [15%] of 452 women, risk ratio 0·45, 95% CI 0·30-0·67; p=0·0001). The incidence of any malaria infection during pregnancy or delivery was 25·4 per 100 person-years in the co-trimoxazole plus dihydroartemisinin-piperaquine group versus 77·3 per 100 person-years in the co-trimoxazole plus placebo group (incidence rate ratio 0·32, 95% CI 0·22-0·47, p<0·0001). The number needed to treat to avert one malaria infection per pregnancy was 7 (95% CI 5-10). The incidence of serious adverse events was similar between groups in mothers (17·7 per 100 person-years in the co-trimoxazole plus dihydroartemisinin-piperaquine group [23 events] vs 17·8 per 100 person-years in the co-trimoxazole group [25 events]) and infants (45·4 per 100 person-years [23 events] vs 40·2 per 100 person-years [21 events]). Nausea within the first 4 days after the start of treatment was reported by 29 (7%) of 446 women in the co-trimoxazole plus dihydroartemisinin-piperaquine group versus 12 (3%) of 445 women in the co-trimoxazole plus placebo group. The risk of adverse pregnancy outcomes did not differ between groups.

INTERPRETATION

Addition of monthly intermittent preventive treatment with dihydroartemisinin-piperaquine to the standard of care with daily unsupervised co-trimoxazole in areas of high antifolate resistance substantially improves malaria chemoprevention in pregnant women living with HIV on dolutegravir-based cART and should be considered for policy.

FUNDING

European and Developing Countries Clinical Trials Partnership 2; UK Joint Global Health Trials Scheme (UK Foreign, Commonwealth and Development Office; Medical Research Council; National Institute for Health Research; Wellcome); and Swedish International Development Cooperation Agency.

Post-discharge malaria chemoprevention in children admitted with severe anaemia in malaria-endemic settings in Africa: a systematic review and individual patient data meta-analysis of randomised controlled trials

BACKGROUND

Severe anaemia is associated with high in-hospital mortality among young children. In malaria-endemic areas, surviving children also have an increased risk of mortality or readmission after hospital discharge. We conducted a systematic review and individual patient data meta-analysis to determine the efficacy of monthly post-discharge malaria chemoprevention in children recovering from severe anaemia.

METHODS

This analysis was conducted according to PRISMA-IPD guidelines. We searched multiple databases on Aug 28, 2023, without date or language restrictions, for randomised controlled trials comparing monthly post-discharge malaria chemoprevention with placebo or standard of care among children (aged <15 years) admitted with severe anaemia in malaria-endemic Africa. Trials using daily or weekly malaria prophylaxis were not eligible. The investigators from all eligible trials shared pseudonymised datasets, which were standardised and merged for analysis. The primary outcome was all-cause mortality during the intervention period. Analyses were performed in the modified intention-to-treat population, including all randomly assigned participants who contributed to the endpoint. Fixed-effects two-stage meta-analysis of risk ratios (RRs) was used to generate pooled effect estimates for mortality. Recurrent time-to-event data (readmissions or clinic visits) were analysed using one-stage mixed-effects Prentice-Williams-Peterson total-time models to obtain hazard ratios (HRs). This study is registered with PROSPERO, CRD42022308791.

FINDINGS

Our search identified 91 articles, of which 78 were excluded by title and abstract, and a further ten did not meet eligibility criteria. Three double-blind, placebo-controlled trials, including 3663 children with severe anaemia, were included in the systematic review and meta-analysis; 3507 (95·7%) contributed to the modified intention-to-treat analysis. Participants received monthly sulfadoxine-pyrimethamine until the end of the malaria transmission season (mean 3·1 courses per child [range 1-6]; n=1085; The Gambia), monthly artemether-lumefantrine given at the end of weeks 4 and 8 post discharge (n=1373; Malawi), or monthly dihydroartemisinin-piperaquine given at the end of weeks 2, 6, and 10 post discharge (n=1049; Uganda and Kenya). During the intervention period, post-discharge malaria chemoprevention was associated with a 77% reduction in mortality (RR 0·23 [95% CI 0·08-0·70], p=0·0094, I2=0%) and a 55% reduction in all-cause readmissions (HR 0·45 [95% CI 0·36-0·56], p<0·0001) compared with placebo. The protective effect was restricted to the intervention period and was not sustained after the direct pharmacodynamic effect of the drugs had waned. The small number of trials limited our ability to assess heterogeneity, its sources, and publication bias.

INTERPRETATION

In malaria-endemic Africa, post-discharge malaria chemoprevention reduces mortality and readmissions in recently discharged children recovering from severe anaemia. Post-discharge malaria chemoprevention could be a valuable strategy for the management of this group at high risk. Future research should focus on methods of delivery, options to prolong the protection duration, other hospitalised groups at high risk, and interventions targeting non-malarial causes of post-discharge morbidity.

FUNDING

The Research-Council of Norway and the Bill-&-Melinda-Gates-Foundation through the Worldwide-Antimalarial-Research-Network.

Safety and tolerability of repeated doses of dihydroartemisinin-piperaquine for intermittent preventive treatment of malaria in pregnancy: a systematic review and an aggregated data meta-analysis of randomized controlled trials

BACKGROUND

Malaria infection during pregnancy is an important cause of maternal and infant mortality and morbidity with the greatest effect being concentrated in sub-Saharan Africa. In areas of moderate to high malaria transmission, the World Health Organization (WHO) recommends the administration of intermittent preventive treatment of malaria in pregnancy (IPTp) using sulfadoxine-pyrimethamine (SP) to be given to all pregnant women at each scheduled antenatal care visit at monthly intervals. However, there is concern that increased resistance has compromised its effectiveness. This has led to a need for evaluation of alternatives to SP for IPTp with dihydroartemisinin-piperaquine (DP) emerging as a very promising candidate. Thus, this systematic review and aggregated data meta-analysis was conducted to establish the safety and tolerability of repeated doses with DP in IPTp.

METHODS

A systematic review and aggregated data meta-analysis of randomized controlled trials (RCTs) was performed by searching electronic databases of PubMed, Science Direct, ClinicalTrials.gov and Google Scholar. RCTs comparing IPTp DP versus recommended standard treatment for IPTp with these outcome measures were analyzed; change in QTc interval, serious adverse events (SAE), grade 3 or 4 adverse events possibly related to study drug and vomiting within 30 min after study drug administration. The search was performed up to 24th June 2023. Data was extracted from eligible studies and an aggregated data meta-analysis was carried out with data pooled as risk ratio (RR) with a 95% confidence interval (CI), using RevMan software (5.4). This study is registered with PROSPERO, CRD42022310041.

RESULTS

Six RCTs involving 7969 participants were included in this systematic review and aggregated data meta-analysis. The pooled analysis showed that DP was associated with a change from baseline of the QTc interval although this change was not associated with cardiotoxicity. There was no statistically significant difference in the risk of occurrence of SAEs among participants in both treatment groups (RR = 0.80, 95% CI [0.52-1.24], P = 0.32). However, significant difference was observed in grade 3 or 4 AEs possibly related to study drug where analysis showed that subjects on IPT DP were statistically significantly more likely to experience an AE possibly related to study drug than subjects on IPT SP (RR = 6.65, 95% CI [1.18-37.54], P = 0.03) and in vomiting within 30 min after study drug administration where analysis showed that the risk of vomiting is statistically significantly higher in subjects receiving IPT DP than in subjects receiving IPT SP (RR = 1.77, 95% CI [1.02-3.07], P = 0.04).

CONCLUSION

DP was associated with a higher risk of grade 3 or 4 AEs possibly related to study drug and a higher risk of vomiting within 30 min after study drug administration. However, these were experienced in a very small percentage of women and did not affect adherence to study drugs. DP was also better tolerated in these studies as compared to most alternatives that have been proposed to replace SP which have proved to be too poorly tolerated in IPTp use.

Adapting the preterm birth phenotyping framework to a low-resource, rural setting and applying it to births from Migori County in western Kenya

BACKGROUND

Preterm birth is the leading cause of neonatal and under-five mortality worldwide. It is a complex syndrome characterized by numerous etiologic pathways shaped by both maternal and fetal factors. To better understand preterm birth trends, the Global Alliance to Prevent Prematurity and Stillbirth published the preterm birth phenotyping framework in 2012 followed by an application of the model to a global dataset in 2015 by Barros, et al. Our objective was to adapt the preterm birth phenotyping framework to retrospective data from a low-resource, rural setting and then apply the adapted framework to a cohort of women from Migori, Kenya.

METHODS

This was a single centre, observational, retrospective chart review of eligible births from November 2015 - March 2017 at Migori County Referral Hospital. Adaptations were made to accommodate limited diagnostic capabilities and data accuracy concerns. Prevalence of the phenotyping conditions were calculated as well as odds of adverse outcomes.

RESULTS

Three hundred eighty-seven eligible births were included in our study. The largest phenotype group was none (no phenotype could be identified; 41.1%), followed by extrauterine infection (25.1%), and antepartum stillbirth (16.7%). Extrauterine infections included HIV (75.3%), urinary tract infections (24.7%), malaria (4.1%), syphilis (3.1%), and general infection (3.1%). Severe maternal condition was ranked fourth (15.6%) and included anaemia (69.5%), chronic respiratory distress (22.0%), chronic hypertension prior to pregnancy (5.1%), diabetes (3.4%), epilepsy (3.4%), and sickle cell disease (1.7%). Fetal anaemia cases were the most likely to transfer to the newborn unit (OR 5.1, 95% CI 0.8, 30.9) and fetal anomaly cases were the most likely to result in a pre-discharge mortality (OR 3.9, 95% CI 0.8, 19.2).

CONCLUSIONS

Using routine data sources allowed for a retrospective analysis of an existing dataset, requiring less time and fewer resources than a prospective study and demonstrating a feasible approach to preterm phenotyping for use in low-resource settings to inform local prevention strategies.

Malaria-specific Type 1 regulatory T cells are more abundant in first pregnancies and associated with placental malaria

BACKGROUND

Malaria in pregnancy (MIP) causes higher morbidity in primigravid compared to multigravid women; however, the correlates and mechanisms underlying this gravidity-dependent protection remain incompletely understood. We aimed to compare the cellular immune response between primigravid and multigravid women living in a malaria-endemic region and assess for correlates of protection against MIP.

METHODS

We characterised the second trimester cellular immune response among 203 primigravid and multigravid pregnant women enrolled in two clinical trials of chemoprevention in eastern Uganda, utilizing RNA sequencing, flow cytometry, and functional assays. We compared responses across gravidity and determined associations with parasitaemia during pregnancy and placental malaria.

FINDINGS

Using whole blood RNA sequencing, no significant differentially expressed genes were identified between primigravid (n = 12) and multigravid (n = 11) women overall (log 2(FC) > 2, FDR < 0.1). However, primigravid (n = 49) women had higher percentages of malaria-specific, non-naïve CD4+ T cells that co-expressed IL-10 and IFNγ compared with multigravid (n = 85) women (p = 0.000023), and higher percentages of these CD4+ T cells were associated with greater risks of parasitaemia in pregnancy (Rs = 0.49, p = 0.001) and placental malaria (p = 0.0073). These IL-10 and IFNγ co-producing CD4+ T cells had a genomic signature of Tr1 cells, including expression of transcription factors cMAF and BATF and cell surface makers CTLA4 and LAG-3.

INTERPRETATION

Malaria-specific Tr1 cells were highly prevalent in primigravid Ugandan women, and their presence correlated with a higher risk of malaria in pregnancy. Understanding whether suppression of Tr1 cells plays a role in naturally acquired gravidity-dependent immunity may aid the development of new vaccines or treatments for MIP.

FUNDING

This work was funded by NIH (PO1 HD059454, U01 AI141308, U19 AI089674, U01 AI155325, U01 AI150741), the March of Dimes (Basil O'Connor award), and the Bill and Melinda Gates Foundation (OPP 1113682).

Malaria in Pregnancy: Key Points for the Neonatologist

In malaria-endemic regions, infection with the malaria parasite Plasmodium during pregnancy has been identified as a key modifiable factor in preterm birth, the delivery of low-birthweight infants, and stillbirth. Compared with their nonpregnant peers, pregnant persons are at higher risk for malaria infection. Malaria infection can occur at any time during pregnancy, with negative effects for the pregnant person and the fetus, depending on the trimester in which the infection is contracted. Pregnant patients who are younger, in their first or second pregnancy, and those coinfected with human immunodeficiency virus are at increased risk for malaria. Common infection prevention measures during pregnancy include the use of insecticide-treated bed nets and the use of intermittent preventive treatment with monthly doses of antimalarials, beginning in the second trimester in pregnant patients in endemic areas. In all trimesters, artemisinin-combination therapies are the first-line treatment for uncomplicated falciparum malaria, similar to treatment in nonpregnant adults. The World Health Organization recently revised its recommendations, now listing the specific medication artemether-lumefantrine as first-line treatment for uncomplicated malaria in the first trimester. While strong prevention and detection methods exist, use of these techniques remains below global targets. Ongoing work on approaches to treatment and prevention of malaria during pregnancy remains at the forefront of global maternal child health research.

Intermittent preventive treatment with Sulfadoxine pyrimethamine for malaria: a global overview and challenges affecting optimal drug uptake in pregnant women

Malaria in Pregnancy (MiP) leading to morbidity and mortality is a major public health problem that poses significant risk to pregnant women and their fetus. To cope with this alarming situation, administration of Sulfadoxine-pyrimethamine (SP) drugs to pregnant women as an intermittent preventive treatment (IPT) from 16 weeks of gestation is recommended by the World Health Organization (WHO) guidelines. We conducted a comprehensive search of published articles related to MiP in last 10 years with predefined keywords or their synonyms. The mapping of malaria in pregnant women showed a prevalence rate up to 35% in many countries. Although IPTp-SP has been implemented in endemic regions since several years but the IPTp-SP coverage percentage vary from country to country and continue to remain below the target of 80%. Major reasons for low IPTp-SP involve gestational age at first prenatal visit, level of education, place of residence, knowledge of IPTp-SP benefits, and use of antenatal services. Several challenges including the emergence of septuple and octuple SP-resistant parasites is reported from many countries which make the prophylactic use of IPTp-SP currently debatable. This narrative review addresses the barriers for optimal use of IPTp-SP and discusses alternative approaches to increase the use and effectiveness of SP intervention for preventing MiP. The COVID pandemic has drastically affected the public health disrupting the management of diseases worldwide. In view of this, a brief summary of COVID impact on MiP situation is also included.

Coinfections of malaria and sexually transmitted and reproductive tract infections in pregnancy in sub-Saharan Africa: a systematic review and individual participant data meta-analysis protocol

INTRODUCTION

Malaria infection and curable sexually transmitted infections and reproductive tract infections (STIs/RTIs) adversely impact pregnancy outcomes. In sub-Saharan Africa, the prevalence of malaria and curable STIs/RTIs is high and, where coinfection is common, combination interventions may be needed to improve pregnancy outcomes. The aim of this systematic review is to estimate the prevalence of malaria and curable STI/RTI coinfection during pregnancy, risk factors for coinfection and prevalence of associated adverse pregnancy outcomes.

METHODS AND ANALYSIS

We will use three electronic databases, PubMed, EMBASE and Malaria in Pregnancy Library to identify studies involving pregnant women attending routine antenatal care facilities in sub-Saharan Africa and reporting malaria and curable STI/RTI test results, published in any language since 2000. We will search databases in the second quarter of 2023 and repeat the search before completion of our analyses. The first two authors will screen titles and abstracts, selecting studies that meet inclusion criteria and qualify for full-text screening. If agreement on inclusion/exclusion cannot be reached, the last author will serve as arbiter. We will extract data from eligible publications for a study-level meta-analysis. We will contact research groups of included studies and request individual participant data for meta-analysis. The first two authors will conduct a quality appraisal of included studies using the GRADE system. The last author will adjudicate if the first two authors do not agree on any appraisals. We will conduct sensitivity analyses to test the robustness of effect estimates over time (by decade and half-decade periods), geography (East/Southern Africa vs West/Central Africa), gravidity (primigravidae, secundigravidae, multigravidae), treatment type and dosing frequency, and malaria transmission intensity.

ETHICS AND DISSEMINATION

We obtained ethics approval from the London School of Hygiene & Tropical Medicine (LSHTM Ethics Ref: 26167). Results of this study will be disseminated via peer-reviewed publication and presentation at scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42021224294.

Efavirenz-Based Antiretroviral Therapy but Not Pregnancy Increased Unbound Piperaquine Exposure in Women during Malaria Chemoprevention

Dihydroartemisinin-piperaquine (DP) is highly effective for malaria chemoprevention during pregnancy, but the standard dosing of DP that is used for nonpregnant adults may not be optimal for pregnant women. We previously reported that the pharmacokinetic exposure of total piperaquine (PQ; both bound and unbound to plasma proteins) is reduced significantly in the context of pregnancy or efavirenz (EFV)-based antiretroviral therapy (ART). However, as PQ is >99% protein-bound, reduced protein binding during pregnancy may lead to an increase in the pharmacologically active unbound drug fraction (fu), relative to the total PQ. We investigated the impact of pregnancy and EFV use on the fu of PQ to inform the interpretation of pharmacokinetics. Plasma samples from 0 to 24 h after the third (final) DP dose were collected from pregnant women at 28 weeks gestation who were receiving or not receiving EFV-based ART as well as from women 34 to 54 weeks postpartum who were not receiving EFV-based ART, who served as controls. Unbound PQ was quantified via ultrafiltration and liquid chromatography-tandem mass spectrometry, with fu being calculated as PQunbound/PQtotal. The geometric mean fu did not differ between pregnant and postpartum women (P = 0.66), but it was 23% (P < 0.01) greater in pregnant women receiving EFV-based ART, compared to that in postpartum women who were not receiving EFV-based ART. The altered drug-protein binding, potentially due to the displacement of PQ from plasma proteins by EFV, resulted in only a 14% lower unbound PQ exposure (P = 0.13) in the presence of a 31% lower total PQ exposure (P < 0.01), as estimated by the area under the concentration time curve from 0 to 24 h post-last dose in pregnant women who were receiving EFV-based ART. The results suggest that the impact of pregnancy and EFV-based ART on the exposure and, in turn, the efficacy of PQ for malaria prevention may not be as significant as was suggested by the changes in the total PQ exposure. Further study during the terminal elimination phase (e.g., on day 28 post-dose) would help better characterize the unbound PQ exposure during the full dosing interval and, thus, the overall efficacy of PQ for malaria chemoprevention in this special population.

Perceptions of sulphadoxine-pyrimethamine use among pregnant women in sub-Saharan Africa: a scoping review

Background

Malaria is a major global public health issue that disproportionately affects pregnant women in sub-Saharan Africa. The World Health Organization recommends intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) for its control. Despite its proven efficacy, drug uptake remains low. Sulphadoxine-pyrimethamine (SP) safety concerns have been cited as one of several reasons for this low uptake.

Methods

We conducted a scoping review using the Arksey and O'Malley framework and the health belief model to investigate perceptions of SP use among pregnant women in sub-Saharan Africa. We looked for peer-reviewed publications in five international databases.

Results

The review included 19 articles out of a total of 246. It showed that pregnant women in sub-Saharan Africa have a good understanding of malaria and its consequences, but this does not necessarily translate into increased IPTp-SP uptake. It is worrisome to know that some pregnant women (from 2 studies) did not believe that SP use is beneficial, and several participants (from 4 studies) were unsure or did not see the drug as an effective intervention. Many pregnant women believe SP harms them, their partners, or their unborn children.

Conclusions

Healthcare professionals should continue prescribing and encouraging pregnant women to use SP for malaria prevention until a better substitute becomes available.

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.

FUNDING

European & Developing Countries Clinical Trials Partnership 2, supported by the EU, and the UK Joint-Global-Health-Trials-Scheme of the Foreign, Commonwealth and Development Office, Medical Research Council, Department of Health and Social Care, Wellcome, and the Bill-&-Melinda-Gates-Foundation.

Hydroxyurea treatment is associated with lower malaria incidence in children with sickle cell anemia in sub-Saharan Africa

Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) provides hydroxyurea at maximum tolerated dose (MTD) for children with sickle cell anemia (SCA) in sub-Saharan Africa. Beyond reducing SCA-related clinical events, documented treatment benefits include ∼50% reduction in malaria incidence. To identify associations and propose mechanisms by which hydroxyurea could be associated with lower malaria rates, infections were recorded across all clinical sites (Angola, Democratic Republic of Congo, Kenya, and Uganda). Hazard ratios (HR) with 95% confidence intervals (CIs) for baseline demographics, and time-varying laboratory and clinical parameters were estimated in a modified Cox gap-time model for repeated events. Over 3387 patient-years of hydroxyurea treatment, 717 clinical malaria episodes occurred in 336 of 606 study participants; over half were confirmed by blood smear and/or rapid diagnostic testing with 97.8% Plasmodium falciparum. In univariate analysis limited to 4 confirmed infections per child, malaria risk was significantly associated with absolute neutrophil count (ANC), splenomegaly, hemoglobin, and achieving MTD; age, malaria season, MTD dose, fetal hemoglobin, α-thalassemia, and glucose-6-phosphate dehydrogenase deficiency had no effect. In multivariable regression of confirmed infections, ANC was significant (HR, 1.37 per doubled value; 95% CI, 1.10-1.70; P = .0052), and ANC values <3.0 × 109/L were associated with lower malaria incidence. Compared with nonpalpable spleen, 1- to 4-cm splenomegaly also was associated with higher malaria risk (HR, 2.01; 95% CI, 1.41-2.85; P = .0001). Hydroxyurea at MTD is associated with lower malaria incidence in SCA through incompletely defined mechanisms, but treatment-associated mild myelosuppression with ANC <3.0 × 109/L is salutary. Splenomegaly is an unexplained risk factor for malaria infections among children with SCA in Africa.

Sub-microscopic Plasmodium falciparum parasitaemia, dihydropteroate synthase (dhps) resistance mutations to sulfadoxine-pyrimethamine, transmission intensity and risk of malaria infection in pregnancy in Mount Cameroon Region

BACKGROUND

Plasmodium falciparum resistance to intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) continues to spread throughout sub-Saharan Africa. This study assessed the occurrence of microscopic and sub-microscopic P. falciparum parasitaemia, dihydropteroate synthase mutations associated with resistance to SP and maternal anaemia in the Mount Cameroon area.

METHODS

Consenting pregnant women living in semi-rural and semi-urban/urbanized settings were enrolled in this cross-sectional study. Socio-demographic, antenatal and clinical data were documented. Microscopic and sub-microscopic parasitaemia were diagnosed using peripheral blood microscopy and nested polymerase chain reaction (PCR) respectively. The dhps mutations were genotyped by restriction fragment length polymorphism analysis. The presence of A437G, K540E, and A581G was considered a marker for high-level resistance. Haemoglobin levels and anaemia status were determined.

RESULTS

Among the women, the prevalence of microscopic and sub-microscopic P. falciparum infection were 7.7% (67/874) and 18.6% (93/500) respectively. Predictors of microscopic infection were younger age (< 21 years) (AOR = 2.89; 95% CI 1.29-6.46) and semi-rural settings (AOR = 2.27; 95% CI 1.31-3.96). Determinants of sub-microscopic infection were the rainy season (AOR, 3.01; 95% CI 1.77-5.13), primigravidity (AOR = 0.45; 95% CI 0.21-0.94) and regular ITN usage (AOR = 0.49; 95% CI 0.27-0.90). Of the145 P. falciparum isolates genotyped, 66.9% (97) carried mutations associated with resistance to SP; 33.8% (49), 0%, 52.4% (76) and 19.3% (28) for A437G, K540E, A581G and A437G + A581G respectively. The A581G mutation was associated with ≥ 3 SP doses evident only among sub-microscopic parasitaemia (P = 0.027) and multigravidae (P = 0.009). Women with microscopic infection were more likely from semi-rural settings (AOR = 7.09; 95% CI 2.59-19.42), to report history of fever (AOR = 2.6; 95% CI 1.07-6.31), to harbour parasites with double resistant mutations (AOR = 6.65; 95% CI 1.85-23.96) and were less likely to have received 2 SP doses (AOR = 0.29; 95% CI 1.07-6.31). Microscopic infection decreased Hb levels more than sub-microscopic infection.

CONCLUSION

The occurrence of sub-microscopic P. falciparum parasites resistant to SP and intense malaria transmission poses persistent risk of malaria infection during pregnancy in the area. ITN usage and monitoring spread of resistance are critical.

Effect of Malaria and Malaria Chemoprevention Regimens in Pregnancy and Childhood on Neurodevelopmental and Behavioral Outcomes in Children at 12, 24, and 36 Months: A Randomized Clinical Trial

BACKGROUND

Malaria in pregnancy has been associated with worse cognitive outcomes in children, but its association with behavioral outcomes and the effectiveness of malaria chemoprevention on child neurodevelopment are not well characterized.

METHODS

To determine if more effective malaria chemoprevention in mothers and their children results in better neurodevelopment, 305 pregnant women were randomly assigned to 3 doses of sulfadoxine-pyrimethamine, 3 doses of dihydroartemisinin-piperaquine (DP), or monthly DP during pregnancy, and their 293 children were assigned to DP every 3 months or monthly DP from 2 to 24 months of age. Cognition, language, and motor function were assessed at 12, 24. and 36 months of age, and attention, memory, behavior, and executive function were assessed at 24 and 36 months of age.

RESULTS

Children of mothers with versus without malaria in pregnancy had worse scores on cognitive, behavioral, and executive function outcomes at 24 months. Clinical malaria in children within the first 12 months was similarly associated with poorer scores in behavior and executive function at 24 months, language at 24 and 36 months, and motor function scores at 36 months. However, more effective malaria chemoprevention in the mothers and children was not associated with better outcomes.

CONCLUSIONS

Malaria in pregnancy was associated with worse cognitive, behavioral, and executive function scores in affected children, but more effective malaria chemoprevention measures did not result in better outcomes. Malaria chemoprevention prior to and early in gestation and with even higher efficacy in mothers and children may be required to prevent neurodevelopmental impairment in children. Clinical Trials Registration. NCT02557425.

Superiority trial of intermittent treatment with dihydroartemisinin–piperaquine versus sulfadoxine–pyrimethamine for the prevention of malaria during pregnancy

Background

Malaria in pregnancy is responsible for various adverse maternal and birth outcomes. The emerging resistance to sulfadoxine–pyrimethamine (SP) raises important concerns about its use for intermittent preventive treatment in pregnancy (IPTp) in Africa. This trial aimed to assess the efficacy and safety of IPTp with dihydroartemisinin–piperaquine (DP) as an alternative to IPTp with SP.

Results

The double-blind, randomized, and controlled superiority trial was conducted between July 2020 and June 2021. A total of 250 women were enrolled and randomly assigned to receive SP (n = 125) or DP (n = 125). Two hundred and six (82.4%) participants that contributed to the outcomes were included in the modified intention-to-treat (ITT) analysis, while 84 participants that completed the three courses of the study drugs were included in the per protocol (PP) analysis. The ITT analysis results showed that the incidence of histopathologically confirmed placental malaria was nonsignificantly higher in the DP group compared with the SP group (62.5% vs. 51.1%, P = 0.098). After adjusting for confounders, the risk of histopathologically confirmed placental malaria was also nonsignificantly higher in the DP group (Adjusted Relative Risk [RR] = 1.27, 95% CI 0.94–1.71) compared with the SP group. In contrast, the risk of a low APGAR score was significantly lower in the DP group (RR = 0.45, 95% CI 0.38–0.52) compared with the SP group. Also, the risk of a composite adverse birth outcome (low birth weight or preterm delivery or neonates small for the gestational age) was nonsignificantly lower in the DP group (Adjusted RR = 0.82, 95% CI 0.55–1.21) compared with the SP group. Both drugs were well tolerated, although nausea and vomiting occurred in a significant number of participants in the SP group.

Conclusions

A three-course IPTp with DP was safe and was not found to be superior to IPTp with SP in the prevention of placental malaria. Although IPTp with DP was associated with a significant lower risk of low APGAR score and nonsignificant lower risks of other adverse birth outcomes compared with IPTp with SP.

Trial registration

PACTR, PACTR202002644579177. Registered 20 February 2020, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=9753.

Effects of anti-malarial prophylaxes on maternal transfer of Immunoglobulin-G (IgG) and association to immunity against Plasmodium falciparum infections among children in a Ugandan birth cohort

BACKGROUND

The in-utero transfer of malaria specific IgG to the fetus in Plasmodium falciparum infected pregnant women potentially plays a role in provision of immune protection against malaria in the first birth year. However, the effect of Intermittent Prophylactic Treatment in Pregnancy (IPTp) and placental malaria on the extent of in-utero antibody transfer in malaria endemic regions like Uganda remain unknown. The aim of this study was thus to establish the effect of IPTp on in-utero transfer of malaria specific IgG to the fetus and the associated immune protection against malaria in the first birth year of children born to mothers who had P. falciparum infection during pregnancy in Uganda.

METHODS

We screened a total of 637 cord blood samples from a double blinded randomized clinical trial on Sulfadoxine-Pyrimethamine (SP) and Dihydroartemisinin-Piperaquine (DP) IPTp in a Ugandan birth cohort; study conducted from Busia, Eastern Uganda. Luminex assay was used to measure the cord levels of IgG sub-types (IgG1, IgG2, IgG3 and IgG4) against 15 different P. falciparum specific antigens, with tetanus toxoid (t.t) as a control antigen. Man-Whitney U test (non-parametric) in STATA (ver15) was used in statistical analysis of the samples. In addition, Multivariate cox regression analysis was used to determine the effect of maternal transfer of IgG on the incidence of malaria in the first birth year of children under study.

RESULTS

Mothers on SP expressed higher levels of cord IgG4 against erythrocyte binding antigens (EBA140, EBA175 and EBA181) (p<0.05). Placental malaria did not affect cord levels of IgG sub-types against selected P. falciparum specific antigens (p>0.05). Children who expressed higher levels (75th percentile) of total IgG against the six key P. falciparum antigens (Pf SEA, Rh4.2, AMA1, GLURP, Etramp5Ag1 and EBA 175) had higher risk of malaria in the first birth year; AHRs: 1.092, 95% CI: 1.02-1.17 (Rh4.2); 1.32, 95% CI: 1.00-1.74 (PfSEA); 1.21, 95%CI: 0.97-1.52 (Etramp5Ag1); 1.25, 95%CI: 0.98-1.60 (AMA1); 1.83, 95%CI: 1.15-2.93 (GLURP) (GLURP), and 1.35,; 95%CI: 1.03-1.78 (EBA175). Children born to mothers categorized as poorest had the highest risk of malaria infections in the first birth year (AHR: 1.79, 95% CI: 1.31-2.4). Children born to mothers who had malaria infections during gestation had higher risk of getting malaria in the first birth year (AHR 1.30; 95%CI: 0.97-1.7).

CONCLUSION

Malaria prophylaxis in pregnant mothers using either DP or SP does not affect expression of antibodies against P. falciparum specific antigens in the cord blood. Poverty and malaria infections during pregnancy are key risk factors of malaria infections in the first birth year of growth of children. Antibodies against P. falciparum specific antigens does not protect against parasitemia and malaria infections in the first birth year of children born in malaria endemic areas.

Sex-Linked Differences in Malaria Risk Across the Lifespan

Despite the high burden of malaria worldwide, there is surprisingly scarce research on sex-based differences in malaria outside of pregnancy. A more thorough understanding of sexual dimorphism in malaria, and what underlies these sex-based differences, could elucidate the underlying mechanisms driving malaria pathogenesis and has the potential to inform malaria control efforts, including new vaccines. This review summarizes our current understanding of sex-based differences in the epidemiology of malaria across the lifespan, potential sex- or gender-based mechanisms driving these differences, and the knowledge gaps that need to be addressed.

Reproductive and endocrine effects of artemisinin, piperaquine, and artemisinin-piperaquine combination in rats

BACKGROUND

The WHO recommends artemisinin-based combination regimens for uncomplicated Plasmodium falciparum malaria. One such combination is artemisinin-piperaquine tablets (ATQ). ATQ has outstanding advantages in anti-malarial, such as good efficacy, fewer side effects, easy promotion and application in deprived regions. However, the data about the reproductive and endocrine toxicity of ATQ remains insufficient. Thus, we assessed the potential effects of ATQ and its individual components artemisinin (ART) and piperaquine (PQ) on the reproductive and endocrine systems in Wistar rats.

METHODS

The unfertilized female rats were intragastric administrated with ATQ (20, 40, and 80 mg/kg), PQ (15, 30, and 60 mg/kg), ART (2.5, 5, and 10 mg/kg), or water (control) for 14 days, respectively. The estrous cycle and serum levels of estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), prostaglandin (PG), and adrenocorticotropic hormone (ACTH) were determined. The weights of the kidney, adrenal gland, uterus, and ovaries were measured. The histopathological examinations of the adrenal gland, ovary, uterus, and mammary gland were performed.

RESULTS

Compared with the control group, there were no significant differences in the examined items of female rats in the ART groups, including general observation, estrous cycle, hormonal level, organ weight, and histopathological examination. The estrous cycle of female rats was disrupted within 4-7 days after ATQ or PQ administration, and then in a persistent dioestrus phase. At the end of administration, ATQ and PQ at three doses induced decreased PG, increased ACTH, increased adrenal weight and size, and pathological lesions in the adrenal gland and ovary, including vasodilation and hyperemia in the adrenal cortex and medulla as well as hyperplasia and vacuolar degeneration, ovarian corpus luteum surface hyperemia, numerous but small corpus luteum, and disordered follicle development. But the serum levels of E2, FSH, LH, and PRL did not change obviously. These adverse effects in ATQ or PQ treated rats could not completely disappear after 21 days of recovery.

CONCLUSION

Based on the results of this study, ART had no obvious reproductive and endocrine effects on female rats, while ATQ and PQ caused adrenal hyperplasia, increased ACTH, decreased PG, blocked estrus, corpus luteum surface hyperemia, and disrupted follicle development in female rats. These events suggest that ATQ and PQ may interfere with the female reproductive and endocrine systems, potentially reducing fertility.

In Utero Activation of Natural Killer Cells in Congenital Cytomegalovirus Infection

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the most common infectious cause of birth defects and neurological damage in newborns. Despite a well-established role for natural killer (NK) cells in control of CMV infection in older children and adults, it remains unknown whether fetal NK cells can sense and respond to CMV infection acquired in utero.

METHODS

Here, we investigate the impact of congenital CMV infection on the neonatal NK-cell repertoire by assessing the frequency, phenotype, and functional profile of NK cells in cord blood samples from newborns with congenital CMV and from uninfected controls enrolled in a birth cohort of Ugandan mothers and infants.

RESULTS

We find that neonatal NK cells from congenitally CMV infected newborns show increased expression of cytotoxic mediators, signs of maturation and activation, and an expansion of mature CD56- NK cells, an NK-cell subset associated with chronic viral infections in adults. Activation was particularly prominent in NK cell subsets expressing the Fcγ receptor CD16, indicating a role for antibody-mediated immunity against CMV in utero.

CONCLUSIONS

These findings demonstrate that NK cells can be activated in utero and suggest that NK cells may be an important component of the fetal and infant immune response against CMV.

CLINICAL TRIALS REGISTRATION

NCT02793622.

Piperaquine-Induced QTc Prolongation Decreases With Repeated Monthly Dihydroartemisinin-Piperaquine Dosing in Pregnant Ugandan Women

BACKGROUND

Intermittent preventive treatment with monthly dihydroartemisinin-piperaquine (DHA-PQ) is highly effective at preventing both malaria during pregnancy and placental malaria. Piperaquine prolongs the corrected QT interval (QTc), and it is possible that repeated monthly dosing could lead to progressive QTc prolongation. Intensive characterization of the relationship between piperaquine concentration and QTc interval throughout pregnancy can inform effective, safe prevention guidelines.

METHODS

Data were collected from a randomized controlled trial, where pregnant Ugandan women received malaria chemoprevention with monthly DHA-PQ (120/960 mg DHA/PQ; n = 373) or sulfadoxine-pyrimethamine (SP; 1500/75 mg; n = 375) during the second and third trimesters of pregnancy. Monthly trough piperaquine samples were collected throughout pregnancy, and pre- and postdose electrocardiograms were recorded at 20, 28, and 36 weeks' gestation in each woman. The pharmacokinetics-QTc relationship for piperaquine and QTc for SP were assessed using nonlinear mixed-effects modeling.

RESULTS

A positive linear relationship between piperaquine concentration and Fridericia corrected QTc interval was identified. This relationship progressively decreased from a 4.42 to 3.28 to 2.13 millisecond increase per 100 ng/mL increase in piperaquine concentration at 20, 28, and 36 weeks' gestation, respectively. Furthermore, 61% (n = 183) of women had a smaller change in QTc at week 36 than week 20. Nine women given DHA-PQ had grade 3-4 cardiac adverse events. SP was not associated with any change in QTc.

CONCLUSIONS

Repeated DHA-PQ dosing did not result in increased risk of QTc prolongation and the postdose QTc intervals progressively decreased. Monthly dosing of DHA-PQ in pregnant women carries minimal risk of QTc prolongation.

CLINICAL TRIALS REGISTRATION

NCT02793622.

Drugs for Intermittent Preventive Treatment of Malaria in Pregnancy: Current Knowledge and Way Forward

Malaria infection during pregnancy is an important driver of maternal and neonatal health in endemic countries. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended for malaria prevention at each scheduled antenatal care visit, starting at the second trimester, in areas of high and moderate transmission. However, the increased resistance to SP in some endemic areas challenges its effectiveness. Furthermore, SP is contraindicated in the first trimester of pregnancy and in HIV-infected women on co-trimoxazole prophylaxis due to potential drug–drug interactions. Thus, in recent last decades, several studies evaluated alternative drugs that could be used for IPTp. A comprehensive literature review was conducted to summarize the evidence on the efficacy and safety of antimalarial drugs being evaluated for IPTp. Chloroquine, amodiaquine, mefloquine and azithromycin as IPTp have proven to be worse tolerated than SP. Mefloquine was found to increase the risk of mother-to-child transmission of HIV. Dihydroartemisin-piperaquine currently constitutes the most promising IPTp drug alternative; it reduced the prevalence of malaria infection, and placental and clinical malaria in studies among HIV-uninfected women, and it is currently being tested in HIV-infected women. Research on effective antimalarial drugs that can be safely administered for prevention to pregnant women should be prioritized. Malaria prevention in the first trimester of gestation and tailored interventions for HIV-infected women remain key research gaps to be addressed.

Dihydroartemisinin protects blood-brain barrier permeability during sepsis by inhibiting the transcription factor SNAI1

Blood–brain barrier (BBB) injury is involved in the pathogenesis of sepsis‐associated encephalopathy. In this study, we used dihydroartemisinin (DHA), a derivative of artemisinin, to treat a cecal ligation and puncture (CLP)‐induced mouse sepsis model and a tumour necrosis factor α (TNF‐α)‐stimulated human cerebral microvessel endothelial cells (hCMEC)/D3 cell line. We found that DHA decreased BBB permeability and increased the expression of the tight junction protein occludin (OCLN) in the CLP model. In hCMEC/D3 cells, DHA decreased TNF‐α‐induced hyperpermeability and increased the expression of OCLN. DHA also repressed SNAI1 expression in the CLP mouse model and in TNF‐α‐stimulated hCMEC/D3 cells. These data suggest that DHA protects BBB permeability during sepsis by stimulating the expression of OCLN, by downregulating the expression of the SNAI1 transcription factor.

Malaria chemoprevention and drug resistance: a review of the literature and policy implications

Chemoprevention strategies reduce malaria disease and death, but the efficacy of anti-malarial drugs used for chemoprevention is perennially threatened by drug resistance. This review examines the current impact of chemoprevention on the emergence and spread of drug resistant malaria, and the impact of drug resistance on the efficacy of each of the chemoprevention strategies currently recommended by the World Health Organization, namely, intermittent preventive treatment in pregnancy (IPTp); intermittent preventive treatment in infants (IPTi); seasonal malaria chemoprevention (SMC); and mass drug administration (MDA) for the reduction of disease burden in emergency situations. While the use of drugs to prevent malaria often results in increased prevalence of genetic mutations associated with resistance, malaria chemoprevention interventions do not inevitably lead to meaningful increases in resistance, and even high rates of resistance do not necessarily impair chemoprevention efficacy. At the same time, it can reasonably be anticipated that, over time, as drugs are widely used, resistance will generally increase and efficacy will eventually be lost. Decisions about whether, where and when chemoprevention strategies should be deployed or changed will continue to need to be made on the basis of imperfect evidence, but practical considerations such as prevalence patterns of resistance markers can help guide policy recommendations.

The positive effect of malaria IPTp-SP on birthweight is mediated by gestational weight gain but modifiable by maternal carriage of enteric pathogens

BACKGROUND

Poor pregnancy and birth outcomes are common in sub-Saharan Africa and have complex aetiologies. Sulfadoxine-pyrimethamine (SP), given for intermittent preventive therapy of malaria in pregnancy (IPTp), is one of few existing interventions that improves outcomes of both mother and baby despite widespread SP-resistant malaria. Compelling evidence exists that malaria-independent pathways contribute to this protective effect, but the exact sources of non anti-malarial protection remained unknown. We hypothesized that the beneficial effect of SP on birthweight is mediated by SP activity on maternal factors, including increased gestational weight gain and antibiotic activity on pathogens in the maternal gut.

METHODS

Expectant mothers from a larger randomized control trial comparing the efficacy of IPTp-SP to IPTp with dihydroartemisinin-piperaquine (DP) were also enrolled in this sub-study study at their first antenatal care visit before commencement of IPTp (n = 105). Participants were followed monthly until delivery. Weights and mid-to-upper-arm circumferences (MUAC) were recorded. Monthly stool samples were collected and screened for five Escherichia coli pathotypes, Shigella spp., Vibrio cholerae, Salmonella, Campylobacter coli/jejuni, and three protozoa (Giardia spp., Entameba histolytica, and Cryptosporidium spp.) using previously validated molecular assays.

FINDINGS

IPTp-SP vs. IPTP-DP was associated with higher maternal gestational weight gain (GWG) and nutritional indicators (MUAC and body-mass index, BMI). GWG was found to be a mediator of the birthweight and IPTp-SP relationship, as the birthweight of SP infants, but not DP infants, varied according to maternal GWG. The burden of maternal enteric infections was high. The three most commonly observed pathogens were enteroaggregative E. coli (EAEC), atypical enteropathogenic E.coli/enterohaemorrhagic E. coli (aEPEC/EHEC), and typical enteropathogenic E.coli (tEPEC). We found that SP reduced the prevalence of EAEC in a dose-dependent manner. After 3 or more doses, SP-recipients were 90% less likely to be infected with EAEC compared to DP-recipients (ORadj = 0.07, CI95 = 0.12, 0.39, p = 0.002). Compared to DP, this coincided with higher maternal gestational weight gain (GWG) and nutritional indicators (MUAC and body-mass index, BMI). The beneficial effect of SP on maternal GWG, MUAC and BMI, was lower if SP mothers had detectable EAEC, aEPEC/EHEC, tEPEC, and LT-ETEC at baseline. Maternal EAEC and tEPEC at baseline associated with lower birthweight for babies of both SP mothers and DP mothers. When comparing IPTp regimens, the positive effect of SP on birthweight compared to DP was only observed for infants of women who did not test positive for EAEC at baseline (adjusted mean birthweight difference SP vs. DP = 156.0 g, CI95 = -18.0 g, 336.9 g, p = 0.087), though confidence intervals crossed the null.

INTERPRETATION

Our findings indicate that in pregnant Malawian women, IPTp-SP vs. IPTp-DP is consistently associated with higher MUAC, BMI, and GWG following the WHO-recommended regimen of at least 3 doses, but carriage of maternal gut pathogens before initiation of IPTp lessens this effect. Because GWG was a mediator of the association between birthweight and SP, we show that SP's previously proven positive effect on birthweight is by promoting maternal weight gain. Overall, our results present one plausible pathway SP exerts malaria-independent protection against poor birth outcomes in the context of its waning antimalarial activity and warrants further investigation.

FUNDING

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Prevention of malaria in pregnancy: The threat of sulfadoxine-pyrimethamine resistance

Malaria infection in pregnancy can lead to adverse outcomes for both the pregnant person and fetus. The administration of intermittent preventative therapy (IPTp) with sulfadoxine-pyrimethamine (SP) during pregnancy (IPTp-SP) improves outcomes, including severe maternal anemia, placental malaria infection, and low infant birth weight. The WHO recommends IPTp-SP for pregnant individuals living in areas of moderate or high malaria transmission in Africa. The current regimen consists of two or more doses of SP starting as early as possible in the second trimester, at least 1 month apart. Unfortunately, rising Plasmodium falciparum SP resistance throughout Africa threatens to erode the benefits of SP. Recent studies have shown a decrease in IPTp-SP efficacy in areas with high SP resistance. Thus, there is an urgent need to identify new drug regimens that can be used for intermittent preventative therapy in pregnancy. In this review, we discuss recent data on P. falciparum SP resistance in Africa, the effect of resistance on IPTp-SP, and studies of alternative IPTp regimens. Finally, we present a framework for the ideal pharmacokinetic and pharmacodynamic properties for future IPTp regimens.

Intermittent screening and treatment with artemisinin-combination therapy versus intermittent preventive treatment with sulphadoxine-pyrimethamine for malaria in pregnancy: a systematic review and individual participant data meta-analysis of randomised clinical trials

BACKGROUND

In sub-Saharan Africa, the efficacy of intermittent preventive therapy in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) for malaria in pregnancy is threatened by parasite resistance. We conducted an individual-participant data (IPD) meta-analysis to assess the efficacy of intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with artemisinin-based combination therapy (ISTp-ACT) compared to IPTp-SP, and understand the importance of subpatent infections.

METHODS

We searched MEDLINE and the Malaria-in-Pregnancy Library on May 6, 2021 for trials comparing ISTp-ACT and IPTp-SP. Generalised linear regression was used to compare adverse pregnancy outcomes (composite of small-for-gestational-age, low birthweight (LBW), or preterm delivery) and peripheral or placental Plasmodium falciparum at delivery. The effects of subpatent (PCR-positive, RDT/microscopy-negative) infections were assessed in both arms pooled using multi-variable fixed-effect models adjusting for the number of patent infections. PROSPERO registration: CRD42016043789.

FINDINGS

Five trials conducted between 2007 and 2014 contributed (10,821 pregnancies), two from high SP-resistance areas where dhfr/dhps quintuple mutant parasites are saturated, but sextuple mutants are still rare (Kenya and Malawi), and three from low-resistance areas (West-Africa). Four trials contributed IPD data (N=10,362). At delivery, the prevalence of any malaria infection (relative risk [RR]=1.08, 95% CI 1.00-1.16, I2=67.0 %) and patent infection (RR=1.02, 0.61-1.16, I2=0.0%) were similar. Subpatent infections were more common in ISTp recipients (RR=1.31, 1.05-1.62, I2=0.0%). There was no difference in adverse pregnancy outcome (RR=1.00, 0.96-1.05; studies=4, N=9,191, I2=54.5%). Subpatent infections were associated with LBW (adjusted RR=1.13, 1.07-1.19), lower mean birthweight (adjusted mean difference=32g, 15-49), and preterm delivery (aRR=1.35, 1.15-1.57).

INTERPRETATION

ISTp-ACT was not superior to IPTp-SP and may result in more subpatent infections than the existing IPTp-SP policy. Subpatent infections were associated with increased LBW and preterm delivery. More sensitive diagnostic tests are needed to detect and treat low-grade infections.

FUNDING

Centers for Disease Control and Prevention and Worldwide Antimalarial Resistance Network.

Plasmodium malariae infections as a cause of febrile disease in an area of high Plasmodium falciparum transmission intensity in Eastern Uganda

Background

Plasmodium falciparum is responsible for the vast majority of (severe) clinical malaria cases in most African settings. Other Plasmodium species often go undiagnosed but may still have clinical consequences.

Case presentation

Here, five cases of Plasmodium malariae infections from Eastern Uganda (aged 2–39 years) are presented. These infections were all initially mistaken for P. falciparum, but Plasmodium schizonts (up to 2080/µL) were identified by microscopy. Clinical signs included history of fever and mild anaemia.

Conclusion

These findings highlight the importance of considering non-falciparum species as the cause of clinical malaria. In areas of intense P. falciparum transmission, where rapid diagnostic tests that detect only P. falciparum antigens are commonly used, non-falciparum malaria cases may be missed.