BACKGROUND: Resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine threatens the antimalarial effectiveness of intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (ITPp-SP) in sub-Saharan Africa. We updated an aggregated-data meta-analysis to assess the associations between sulfadoxine-pyrimethamine resistance and the effectiveness of IPTp-SP to inform policy. METHODS: We searched databases (Jan 1, 1990, to June 8, 2024) for observational studies or trials reporting data on malaria, low birthweight (<2500 g), anaemia, and other outcomes by IPTp-SP dose and matched these by year and location with studies that reported on molecular markers of sulfadoxine-pyrimethamine resistance. Studies including only women with HIV or combined interventions were excluded. We evaluated how sulfadoxine-pyrimethamine resistance influenced the adjusted risk ratio (aRR) between three and two doses of IPTp-SP for various outcomes using Poisson mixed-effects models that allowed for non-linear relationships. Initially, we performed a threshold analysis, stratified by region, to identify the resistance levels most predictive of altered effect of IPTp-SP doses on malaria parasitaemia at delivery (peripheral or placental parasitaemia by any test), our primary outcome. These resistance strata were then used in all subsequent models for other outcomes. All analyses were adjusted for malaria transmission intensity, HIV infection, percentage of paucigravidae, and insecticide-treated net use. Performance of models was evaluated using cross-validation. The trial was registered with PROSPERO (CRD42021250359). FINDINGS: Overall, 122 studies involving 148 693 participants were included. For west and central Africa (69 studies comprising 63 745 participants), very low resistance was categorised as a prevalence of the dihydropteroate synthase (dhps) Lys540Glu mutation in the parasite population of less than 4%, and low resistance as a prevalence of Lys540Glu of 4% or higher. In east and southern Africa (53 studies comprising 84 948 participants), moderate resistance was categorised as a prevalence of the Lys540Glu mutation of less than 60% combined with a prevalence of the Ala581Gly mutation of less than 5%, high resistance as a prevalence of Lys540Glu of 60% or higher combined with a prevalence of Ala581Gly of less than 5%, and very high resistance as a prevalence of the Lys540Glu mutation of 60% or higher combined with a prevalence of Ala581Gly of 5% or higher. There was a marked trend towards lower efficacy of IPTp-SP on reducing malaria infection with increasing resistance levels. In west and central Africa, when comparing three versus two doses, the aRR was 0·71 (95% CI 0·65-0·78) in areas with very low resistance and 0·83 (0·72-0·95) in areas with low resistance (p=0·0144 for the difference between dose-response curves in very low vs low resistance). For east and southern Africa, the same trend was observed: the aRR was 0·63 (95% CI 0·57-0·69) in areas with moderate resistance, 0·89 (0·82-0·96) in areas with high resistance, and 0·93 (0·85-1·01) in areas with very high resistance (p<0·0001 for dose-response curves differences between moderate vs high and moderate vs very high resistance). This pattern was not seen for low birthweight. When comparing three versus two doses in west and central Africa, the aRR was 0·58 (95% CI 0·48-0·68) in areas with very low resistance and 0·56 (0·44-0·68) in areas with low resistance (p=0·72 for dose-response curves very low vs low resistance). For east and southern Africa, the aRR was 0·75 (95% CI 0·52-0·98) in areas with moderate resistance, 0·73 (0·69-0·78) in areas with high resistance, and 0·75 (0·63-0·87) in areas with very high resistance (p=0·80 for dose-response curves moderate vs high resistance; p=0·90 for moderate vs very high resistance). Dose comparisons in some resistance strata were limited by sample size. INTERPRETATION: IPTp-SP antimalarial efficacy is greatly reduced in very high resistance areas. However, it remains effective at reducing low birthweight in these areas, possibly through non-malaria effects on fetal growth. While IPTp-SP use should continue in high SP-resistance areas, alternative malaria preventive strategies are urgently needed in these areas. FUNDING: WHO and WorldWide-Antimalarial-Resistance-Network.

Estimates of exposure to coronavirus disease 2019 (COVID-19) on the African continent are limited, constrained by availability of testing and case report data. To improve understanding of COVID-19 burden, monthly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveillance was implemented at first antenatal care visits (ANC1) across six sub-Saharan African countries (Kenya, Malawi, Mozambique, Nigeria, Uganda, and Zambia). A standardized questionnaire, including COVID-19 vaccination history, was administered, and a blood sample was collected. Serology was conducted with two assays: in Nigeria, a multiplex bead-based assay targetting spike protein, receptor binding domain (RBD) 591, and nucleocapsid (N) protein and in all other countries, a SARS-CoV-2 human IgG antibody test including RBD, N protein, and hybrid RBD-N. The largest monthly change in seropositivity was between December 2021 and January 2022 for five countries (Kenya: 33.2-70.3%, Malawi: 28.3-59.6%, Mozambique: 29.3-72.8%, Nigeria: 52.4-77.4%, Uganda: 55.7-80.6%), coinciding with the Omicron wave. Aside from Mozambique, there was an increase in the proportion of women reporting COVID-19 vaccination beginning in January 2022, with highest vaccination rates between April and August 2022. Relatedly, there was an increase in the proportion vaccinated among those with detectable SARS-CoV-2 antibodies. Adenoviral vector accounted for at least half of the vaccines reported in all countries. If pregnant women are not differentially infected, ANC1 can be leveraged for serosurveillance during a pandemic. Monthly seroprevalence estimates alongside vaccination rates can provide evidence for changes in protective immunity in response to case waves and the introduction of protective measures.

BACKGROUND: In 2023, an estimated 36 million pregnancies occurred in malaria endemic sub-Saharan Africa, but only 44% received the WHO recommended ≥ 3 doses of intermittent preventive treatment (IPTp3). Group Antenatal Care (G-ANC) is a service delivery model associated with higher quality of and greater retention in ANC, in which pregnant women are enrolled into groups at their first ANC visit and subsequent care is provided in groups. A cluster-randomized controlled trial was conducted in Atlantique Department, Benin, to assess whether G-ANC improved ANC retention and IPTp3 uptake at community level. METHODS: Forty purposively selected health facilities (HF) were randomized 1:1 to control (individual ANC) or G-ANC. Cross-sectional household surveys to measure uptake of ANC and IPTp were conducted in each HF catchment area before and after implementation among randomly selected women who had given birth in the previous 12 months. Changes in coverage were assessed using a difference-in-difference approach, adjusting for HF clustering. RESULTS: At baseline (N = 1259), coverage of at least 4 ANC visits (ANC4) and IPTp3 was 52.8% and 48.0%, respectively, in the intervention catchment, and 44.9% and 49.4% in the control catchment. Coverage of ANC4 improved in both arms by endline (N = 1280), to 56.7% in the intervention and 46.1% in the control, but the difference in the increase was not significant between arms (p = 0.51). Coverage of IPTp3 increased non-significantly (p = 0.26), to 53.2% (intervention) and 49.7% (control). Overall, only 140 (10.6%) surveyed women reported participating in G-ANC. Participation improved coverage of both ANC4 (65.0% vs 50.5%, p = 0.002; odds ratio (OR) 1.9, 95% CI 1.4-2.5) and IPTp3 (64.0 vs 50.6%, p = 0.004; OR = 1.8, 95% CI 1.2-2.6). CONCLUSIONS: G-ANC increased ANC attendance and IPTp3 uptake among women who participated, but participation was limited. Understanding and addressing the barriers to participation is critical if G-ANC is to be used more widely to increase IPTp coverage. TRIAL REGISTRATION: PACTR202405487752509.

Attractive targeted sugar baits (ATSBs) are a novel malaria control tool designed to target mosquitoes outdoors. We conducted a cluster-randomised trial to evaluate the impact of ATSBs on malaria indicators in Kenya. Seventy clusters (≥100 households/cluster) in Siaya county were randomly assigned (1:1) to intervention or control. Pyrethroid-only long-lasting insecticidal nets were distributed to all clusters, aiming for universal coverage. Two ATSBs containing dinotefuran were hung outside household structures in intervention clusters. ATSBs were monitored every two months and replaced every six months over two years. Three consecutive cohorts of randomly selected children (1- < 15 years) were enrolled, aiming to accrue 1,260 person-years over two years of follow-up. Incidence of clinical malaria (fever with a positive malaria test) was the primary outcome. A multilevel Poisson regression model was applied, with clusters as a random intercept and study arm as a fixed effect. Secondary outcomes were malaria prevalence in community residents (≥1 month), and parity of mosquitos captured through human landing catches. In March 2022, ATSBs were delivered to 33,180 of 33,419 (99.3%) household structures in intervention clusters. Overall, 268,268 ATSBs were deployed over two years. Of 2,962 cohort children enrolled (intervention = 1,497; control = 1,465), 2,869 (96.9%) were included in the primary analysis (intervention = 1,461; control = 1,408), contributing 1,445 person-years of follow-up. Malaria incidence was 1.32 episodes per person-years in the intervention arm versus 1.20 in the control (unadjusted incidence rate ratio 1.11; 95% CI: 0.75-1.65; p = 0.598). Of 7,488 community residents surveyed (intervention = 3,760; control = 3,728), 1,474 (39.2%) intervention and 1,461 (39.2%) control participants tested positive for malaria (unadjusted odds ratio [OR] 0.98; 95% CI: 0.60-1.59; p = 0.93). Of 6,457 female anopheles mosquitoes collected (intervention = 4,058; control = 2,399), 3,579 (88.2%) intervention and 1,973 (82.2%) control mosquitoes were parous (OR 1.34; 95% CI: 0.91-1.99; p = 0.14). In Kenya, we found no evidence that ATSBs reduced clinical malaria incidence, malaria prevalence, or vector parity. Trial registration Clinicaltrials.gov (NCT05219565), 22 January 2022.

Ensuring prompt and effective case management of malaria remains an ongoing challenge in Zambia, where care is not sought for roughly 40% of febrile children under 5 years of age. To expand access, the Ministry of Health has scaled up routine malaria community case management (mCCM) for all ages over the past decade. As of 2018, nearly a quarter of children who received antimalarials obtained them from a community health worker (CHW), but gaps in treatment seeking remain. Proactive community case management (proCCM), under which CHWs regularly visit households to screen, test and treat individuals for malaria, aims to improve timely case management, avert severe disease and potentially reduce transmission. To evaluate the impact of weekly proCCM on malaria parasite prevalence and incidence in the context of strong routine community case management, we conducted a two-arm cluster-randomised controlled trial, comparing proCCM plus routine passive care to routine passive care only in Chadiza District, Eastern Province, Zambia, between April 2021 and May 2023. Baseline and endline surveys were conducted during peak transmission season to ascertain parasite prevalence, while facility, routine mCCM and proCCM incidence data were collected through routine surveillance systems and weekly household visits, respectively. In the control arm, malaria prevalence decreased from 19.7% in 2021 to 16.0% in 2023, and in the intervention arm, from 18.7% to 13.7%. No significant difference between arms in the change in parasite prevalence was estimated (adjusted relative risk=0.97, 95% CI=0.77 to 1.23). However, there was a small, ongoing decline in malaria incidence each month in proCCM clusters compared with control clusters (adjusted incidence rate ratio=0.98, 95% Bayesian credible interval=0.96 to 0.99). Our study suggests proCCM may modestly reduce malaria incidence over time in some settings with high baseline utilisation of routine facility and community case management. Trial registration number: NCT04839900.

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, I(2) = 61%) and BWGA z-scores (MD = 0.12 [95% CI: 0.05-0.20]; p = 0.0012, I(2) = 51%), but not gestational age at birth (MD = 0 weeks [95% CI: -0.11 to 0.12]; p = 0.94; I(2) = 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.

BACKGROUND: Expanding malaria community case management (mCCM) to all ages could shift the point-of-care to the community leading to improved healthcare access in underserved populations. This study assesses the economic viability of such an expansion in Farafangana district, Madagascar. METHODS: A cluster-randomized trial was conducted across 30 health centres and the 502 community health workers (CHW) in their catchment areas, with the intervention arm implementing the age-expanded mCCM intervention. CHWs across both arms received training, supplies, and supervision to manage malaria. An economic evaluation assessed cost-effectiveness from health sector and societal perspectives, measuring outcomes in disability-adjusted life years (DALYs) averted. The impact of CHW compensation and economic risks were evaluated using sensitivity analyses. RESULTS: Without CHW compensation, annual costs were $794,000, primarily for antimalarials and diagnostic tests. Incremental cost-effectiveness ratios (ICERs) per DALY averted ranged from -$21.86 to $212.42. From a societal perspective, the ICER was -$135.64, and -$243.29 including mortality benefits, meaning the intervention was cost-saving. The programme could avert 99.6 deaths and 3,721.7 DALYs annually, yielding $1,172,283 in net economic benefits. Sensitivity analyses supported these findings. CONCLUSIONS: Age-expanded mCCM is highly cost-effective and can enhance malaria treatment access in resource-limited settings.

BACKGROUND: Subpatent Plasmodium falciparum infections, defined as infections with parasite density below the detection limit of routine malaria diagnostic tests, contribute to infectious reservoirs, sustain transmission, and cause the failure of elimination strategies in target areas. This study assessed the prevalence of subpatent P. falciparum infections and associated risk factors in 14 regions of Mainland Tanzania. METHODS: The study used samples randomly selected from RDT-negative dried blood spots (DBS) (n = 2685/10,101) collected in 2021 at 100 health facilities across 10 regions of Mainland Tanzania, and four communities in four additional regions. The regions were selected from four transmission strata; high (five regions), moderate (three regions), low (three regions), and very low (three regions). DNA was extracted by Tween-Chelex method, and the Pf18S rRNA gene was amplified by quantitative polymerase chain reaction (qPCR). Logistic regression analysis was used to assess the associations between age groups, sex, fever status, and transmission strata with subpatent infection status, while linear regression analysis was used to assess the association between these factors and subpatent parasite density. RESULTS: Of the selected samples, 525/2685 (19.6%) were positive by qPCR for P. falciparum, and the positivity rates varied across different regions. Under-fives (aOR: 1.4, 95% CI 1.04-1.88; p < 0.05) from health facilities had higher odds of subpatent infections compared to other groups, while those from community surveys (aOR: 0.33, 95% CI 0.15-0.72; p = 0.005) had lower odds. Participants from very low transmission stratum had significantly lower odds of subpatent infection compared to those from high transmission stratum (aOR = 0.53, 95% CI = 0.37-0.78; p < 0.01). The log-transformed median parasite density (interquartile range) was 6.9 (5.8-8.5) parasites/µL, with significantly higher parasitaemia in the low transmission stratum compared to a very low one (11.4 vs 7.0 parasites/µL, p < 0.001). CONCLUSION: Even in very low transmission settings, the prevalence of subpatent infections was 13%, and in low transmission settings it was even higher at 29.4%, suggesting a substantial reservoir that is likely to perpetuate transmission but can be missed by routine malaria case management strategies. Thus, control and elimination programmes may benefit from adoption of more sensitive detection methods to ensure that a higher proportion of subpatent infections are detected.

BACKGROUND: In Zambia, the true extent of SARS-CoV-2 infections is unknown because initial surveillance focused on patients with symptoms or severe disease. Antenatal sentinel surveillance had not been used to assess infection trends. The ANC COVID-19 surveillance study sought to determine SARS-CoV-2 seroprevalence and COVID-19 vaccine uptake among pregnant women. We provide insight into the study implementation, challenges encountered, best practices, and lessons learned. METHODS: A repeated cross-sectional seroprevalence survey was implemented at 39 health facilities in four districts from September 2021 to September 2022. Pregnant women aged 15-49 years were enrolled at their first antenatal care visits. An electronic questionnaire gathered demographics and other COVID-19 related information from consenting participants. A dried blood sample was collected to detect IgG antibodies using a multiplex bead assay. Seropositive results were categorized as infection, infection and vaccination or infection based on anti-RBD and anti-nucleocapsid test results. Problems and their root causes were identified as they occurred. Practical problem-solving strategies were devised, implemented, and monitored to ensure that goals were accomplished. RESULTS: In the primary analysis, 7% of the 9,221 samples collected from participants were not tested because they were missing. COVID-19 vaccine uptake of 9,111 pregnant women was assessed. Approximately 64% of participants were cumulatively seropositive for SARS-CoV-2 antibodies. Seroprevalence increased from 27.8% in September 2021 to 56.6% in July 2022. We observed an increase in vaccine coverage (0.5-27%) over time. Women aged 40-49 years old, without education and with prior COVID-19 infection were associated with higher vaccine uptake. The Delta variant of COVID-19 and the reallocation of health facilities between two partners delayed surveillance activities and increased the cost of implementation (e.g., the purchase of additional calibration and validation kits and DBS cards). Protocol deviations were attributed to the lack of experience in conducting research but, the district RAs repeatedly trained health facility staff to enhance their research knowledge. CONCLUSIONS: Incorporating SARS-CoV-2 surveillance into routine antenatal care is feasible and potentially sustainable when existing health system infrastructure, human resources, and surveillance systems are leveraged. Yet, careful planning is needed to anticipate implementation challenges and ensure high-quality data collection.

BACKGROUND: In western Kenya, a cluster-randomized trial is assessing the impact of attractive targeted sugar baits (ATSBs) on malaria in children enrolled in three consecutive cohorts. Here, characteristics of children and households at enrolment, and factors associated with baseline malaria prevalence are described. METHODS: Children aged 1 to < 15 years were randomly selected by cluster (n = 70) from a census database. Cohorts were enrolled in March-April 2022, September-October 2022, and March-April 2023. ATSBs were deployed in March 2022. At enrolment, all participants were tested for malaria by rapid diagnostic test (RDT). After enrolment a household survey was conducted. Household structures were classified as 'improved' (finished walls and roofs, and closed eaves) or 'traditional' (all other construction). A generalized linear mixed model was used to assess factors associated with malaria prevalence. RESULTS: Of 3705 children screened, 220 declined and 523 were excluded, due to plans to leave the study area (n = 392), ineligible age (n = 64) or other reason (n = 67). Overall, 2962 children were enrolled. Bed net use the previous night was more common in children aged 1-4 years (746/777 [96%]) than those aged 5-<15 years (1806/2157 [84%], p < 0.001). Of the 2644 households surveyed (for 2,886 participants), information on house construction was available for 2595. Of these, only 199 (8%) were categorized as 'improved', as most houses had open eaves. While 99% of households owned at least one bed net, only 51% were adequately covered (one net per two household residents). Among 999 children enrolled in the first cohort (baseline), 498 (50%) tested positive by RDT. In an adjusted multivariable analysis, factors associated with RDT positivity included sub-county (Alego-Usonga vs Rarieda, adjusted odds ratio [aOR] 4.81; 95% CI: 2.74-8.45; p < 0.001), house construction (traditional vs improved, aOR 2.80; 95% CI: 1.59-4.95; p < 0.001), and age (5-< 15 vs 1-4 years, aOR 1.64; 95% CI: 1.13-2.37; p = 0.009). CONCLUSIONS: In western Kenya, the burden of malaria in children remains high. Most households owned a bed net, but coverage was inadequate. Residents of Alego-Usonga sub-county, those living in traditionally constructed households, and older children were more likely to test positive by RDT. Additional tools are needed to effectively control malaria in this area. Trial registration The ATSB trial is registered under Clinicaltrials.gov NCT05219565.

Pregnant women are considered a high-risk group for COVID-19, and a priority for vaccination. Routine antenatal care (ANC) provides an opportunity to track trends and factors associated with vaccine uptake. We sought to evaluate COVID-19 vaccine uptake among pregnant women attending ANC and assess the factors associated with vaccine in Zambia. We conducted a repeated cross-sectional study in 39 public health facilities in four districts in Zambia from September 2021 to September 2022. Pregnant women who were aged 15-49 years were enrolled during their first ANC visit. Every month, ~20 women per facility were interviewed during individual HIV counseling and testing. We estimated vaccine uptake as the proportion of eligible participants who self-reported having received the COVID-19 vaccine. A total of 9,203 pregnant women were screened, of which 9,111 (99%) were eligible and had vaccination status. Of the 9,111 included in the analysis, 1,818 (20%) had received the COVID-19 vaccine during the study period, with a trend of increasing coverage with time (0.5% in September 2020, 27% in September 2022). Conversely, 3,789 (42%) reported not being offered a COVID-19 vaccine. We found that women aged 40-49 years, had no education or attained some primary school education, were not employed, and had prior COVID-19 infection were significantly associated with vaccine uptake. COVID-19 vaccine uptake among pregnant women was lower than estimates from the general population (27% across the four districts in September 2022), pointing to missed opportunities to protect this high-risk group. ANC visits were a viable point for conducting COVID-19 surveillance. Incorporating the vaccine as part of the routine ANC package might increase coverage in this group.

BACKGROUND: Malaria community case management (CCM) can improve timely access to healthcare, and CCM programmes in sub-Saharan Africa are expanding from serving children under 5 years (CU5) only to all ages. This report characterizes malaria case management in the setting of an age-expanded CCM programme in Chadiza District, Zambia. METHODS: Thirty-three households in each of 73 eligible communities were randomly selected to participate in a household survey preceding a trial of proactive CCM (NCT04839900). All household members were asked about fever in the prior two weeks and received a malaria rapid diagnostic test (RDT); those reporting fever were asked about healthcare received. Weighted population estimates were calculated and mixed effects regression was used to assess factors associated with malaria care seeking. RESULTS: Among 11,030 (98.6%) participants with RDT results (2,357 households), parasite prevalence was 19.1% by RDT; school-aged children (SAC, 5-14 years) had the highest prevalence (28.8%). Prior fever was reported by 12.4% of CU5, 7.5% of SAC, and 7.2% of individuals ≥ 15 years. Among those with prior fever, 34.0% of CU5, 56.0% of SAC, and 22.6% of individuals ≥ 15 years had a positive survey RDT and 73.7% of CU5, 66.5% of SAC, and 56.3% of individuals ≥ 15 years reported seeking treatment; 76.7% across all ages visited a CHW as part of care. Nearly 90% (87.8%) of people who visited a CHW reported a blood test compared with 73.5% seen only at a health facility and/or pharmacy (p < 0.001). Reported malaria treatment was similar by provider, and 85.9% of those with a reported positive malaria test reported getting malaria treatment; 66.9% of the subset with prior fever and a positive survey RDT reported malaria treatment. Age under 5 years, monthly or more frequent CHW home visits, and greater wealth were associated with increased odds of receiving healthcare. CONCLUSIONS: Chadiza District had high CHW coverage among individuals who sought care for fever. Further interventions are needed to increase the proportion of febrile individuals who receive healthcare. Strategies to decrease barriers to healthcare, such as CHW home visits, particularly targeting those of all ages in lower wealth strata, could maximize the benefits of CHW programmes.

BACKGROUND: The WHO 2016 antenatal care (ANC) policy recommends at least eight antenatal contacts during pregnancy. This study assessed ANC8 uptake following policy implementation and explored the relationship between ANC attendance and intermittent preventive treatment in pregnancy (IPTp) coverage in sub-Saharan Africa following the rollout of the World Health Organization (WHO) 2016 ANC policy, specifically, to assess differences in IPTp uptake between women attending eight versus four ANC contacts. METHODS: A secondary analysis of data from 20 sub-Saharan African countries with available Demographic Health and Malaria Indicator surveys from 2018 to 2023 was performed. The key variables were the number of ANC contacts and IPTp doses received during a participant's last completed pregnancy in the past two years. Pooled crude and multivariable logistic regression models were used to explore factors associated with attendance of at least four or eight ANC contacts as well as receipt of at least three doses of IPTp during pregnancy. RESULTS: Overall, only a small proportion of women (median = 3.9%) completed eight or more ANC contacts (ANC8 +). Factors significantly associated with increased odds of ANC8 + included early ANC attendance (AOR: 4.61: 95% CI 4.30-4.95), literacy (AOR: 1.20; 95% CI 1.11-1.29), and higher wealth quintile (AOR: 3.03; 95% CI 2.67-3.44). The pooled estimate across all countries showed a very slight increase in the odds of IPTp3 + among women with eight (AOR: 1.06; 95% CI 1.00-1.12) compared to those with four contacts. In all but two countries, having eight instead of four ANC contacts did not confer significantly greater odds of receiving three or more doses of IPTp (IPTp3 +), except in Ghana (AOR: 1.67; 95% CI 1.38-2.04) and Liberia (AOR: 1.43; 95% CI 1.18-1.72). CONCLUSION: Eight years after the WHO ANC policy recommendation, all countries still had sub-optimal ANC8 + coverage rates. This paper is a call to action to actualize the vision of the WHO and the global malaria community of a malaria free world. Policies to improve ANC and IPTp coverage should be operationalized with clear actionable guidance and local ownership. Study findings can be used to inform multi-level policy, programmatic, and research recommendations to optimize ANC attendance and malaria in pregnancy prevention, thus improving maternal and child health outcomes, including the reduction of malaria in pregnancy.

Malaria continues to be a major source of morbidity and mortality in sub-Saharan Africa. Timely, accurate, and effective case management is critical to malaria control. Proactive community case management (ProCCM) is a new strategy in which a community health worker "sweeps" a village, visiting households at defined intervals to proactively provide diagnostic testing and treatment if indicated. Pilot experiments have shown the potential of ProCCM for controlling malaria transmission; identifying the best strategy for administering ProCCM in terms of interval timings and number of sweeps could lead to further reductions in malaria infections. We developed an agent-based simulation to model malaria transmission and the impact of various ProCCM strategies. The model was validated using symptomatic prevalence data from a ProCCM pilot study in Senegal. Various ProCCM strategies were tested to evaluate the potential for reducing parasitologically confirmed symptomatic malaria cases in the Senegal setting. We found that weekly ProCCM sweeps during a 21-week transmission season could reduce cases by 36.3% per year compared with no sweeps. Alternatively, two initial fortnightly sweeps, seven weekly sweeps, and finally four fortnightly sweeps (13 sweeps total) could reduce confirmed malaria cases by 30.5% per year while reducing the number of diagnostic tests and corresponding costs by about 33%. Under a highly seasonal transmission setting, starting the sweeps early with longer duration and higher frequency would increase the impact of ProCCM, though with diminishing returns. The model is flexible and allows decision-makers to evaluate implementation strategies incorporating sweep frequency, time of year, and available budget.

BACKGROUND: Global progress on malaria control has stalled recently, partly due to challenges in universal access to malaria diagnosis and treatment. Community health workers (CHWs) can play a key role in improving access to malaria care for children under 5 years (CU5), but national policies rarely permit them to treat older individuals. We conducted a two-arm cluster randomized trial in rural Madagascar to assess the impact of expanding malaria community case management (mCCM) to all ages on health care access and use. METHODS: Thirty health centers and their associated CHWs in Farafangana District were randomized 1:1 to mCCM for all ages (intervention) or mCCM for CU5 only (control). Both arms were supported with CHW trainings on malaria case management, community sensitization on free malaria care, monthly supervision of CHWs, and reinforcement of the malaria supply chain. Cross-sectional household surveys in approximately 1600 households were conducted at baseline (Nov-Dec 2019) and endline (Nov-Dec 2021). Monthly data were collected from health center and CHW registers for 36 months (2019-2021). Intervention impact was assessed via difference-in-differences analyses for survey data and interrupted time-series analyses for health system data. RESULTS: Rates of care-seeking for fever and malaria diagnosis nearly tripled in both arms (from less than 25% to over 60%), driven mostly by increases in CHW care. Age-expanded mCCM yielded additional improvements for individuals over 5 years in the intervention arm (rate ratio for RDTs done in 6-13-year-olds, RR(RDT6-13 years) = 1.65; 95% CIs 1.45-1.87), but increases were significant only in health system data analyses. Age-expanded mCCM was associated with larger increases for populations living further from health centers (RR(RDT6-13 years) = 1.21 per km; 95% CIs 1.19-1.23). CONCLUSIONS: Expanding mCCM to all ages can improve universal access to malaria diagnosis and treatment. In addition, strengthening supply chain systems can achieve significant improvements even in the absence of age-expanded mCCM. TRIAL REGISTRATION: The trial was registered at the Pan-African Clinical Trials Registry (#PACTR202001907367187).

Increasing antimicrobial resistance (AMR) is a global public health emergency. Although chemoprevention has improved malaria-related pregnancy outcomes, the downstream effects on AMR have not been characterized. We compared the abundance of 10 AMR genes in stool samples from pregnant women receiving sulfadoxine-pyrimethamine (SP) as intermittent preventive treatment against malaria in pregnancy (IPTp) to that in samples from women receiving dihydroartemisinin-piperaquine (DP) for IPTp. All participants had at least one AMR gene at baseline. Mean quantities of the antifolate gene dfrA17 were increased after two or more doses of SP (mean difference = 1.6, 95% CI: 0.4-2.7, P = 0.008). Antimicrobial resistance gene abundance tended to increase from baseline in SP recipients compared with a downward trend in the DP group. Overall, IPTp-SP had minimal effects on the abundance of antifolate resistance genes (except for dfrA17), potentially owing to a high starting prevalence. However, the trend toward increasing AMR in SP recipients warrants further studies.

SARS-CoV-2 serosurveys help estimate the extent of transmission and guide the allocation of COVID-19 vaccines. We measured SARS-CoV-2 seroprevalence among women attending ANC clinics to assess exposure trends over time in Zambia. We conducted repeated cross-sectional SARS-CoV-2 seroprevalence surveys among pregnant women aged 15-49 years attending their first ANC visits in four districts of Zambia (two urban and two rural) during September 2021-September 2022. Serologic testing was done using a multiplex bead assay which detects IgG antibodies to the nucleocapsid protein and the spike protein receptor-binding domain (RBD). We calculated monthly SARS-CoV-2 seroprevalence by district. We also categorized seropositive results as infection alone, infection and vaccination, or vaccination alone based on anti-RBD and anti-nucleocapsid test results and self-reported COVID-19 vaccination status (vaccinated was having received ≥1 dose). Among 8,304 participants, 5,296 (63.8%) were cumulatively seropositive for SARS-CoV-2 antibodies from September 2021 through September 2022. SARS-CoV-2 seroprevalence primarily increased from September 2021 to September 2022 in three districts (Lusaka: 61.8-100.0%, Chongwe: 39.6-94.7%, Chipata: 56.5-95.0%), but in Chadiza, seroprevalence increased from 27.8% in September 2021 to 77.2% in April 2022 before gradually dropping to 56.6% in July 2022. Among 5,906 participants with a valid COVID-19 vaccination status, infection alone accounted for antibody responses in 77.7% (4,590) of participants. Most women attending ANC had evidence of prior SARS-CoV-2 infection and most SARS-CoV-2 seropositivity was infection-induced. Capturing COVID-19 vaccination status and using a multiplex bead assay with anti-nucleocapsid and anti-RBD targets facilitated distinguishing infection-induced versus vaccine-induced antibody responses during a period of increasing COVID-19 vaccine coverage in Zambia. Declining seroprevalence in Chadiza may indicate waning antibodies and a need for booster vaccines. ANC clinics have a potential role in ongoing SARS-CoV-2 serosurveillance and can continue to provide insights into SARS-CoV-2 antibody dynamics to inform near real-time public health responses.

Many SARS-CoV-2 infections are asymptomatic, thus reported cases underestimate actual cases. To improve estimates, we conducted surveillance for SARS-CoV-2 seroprevalence among pregnant women attending their first antenatal care visit (ANC1) from June 2021 through May 2022. We administered a questionnaire to collect demographic, risk factors, and COVID-19 vaccine status information and tested dried blood spots for SARS-CoV-2 antibodies. Although <1% of ANC1 participants reported having had COVID-19, monthly SARS-CoV-2 seroprevalence increased from 15.4% (95% CI: 10.5-21.5) in June 2021 to 65.5% (95% CI: 55.5-73.7) in May 2022. Although COVID-19 vaccination was available in March 2021, uptake remained low, reaching a maximum of 9.5% (95% CI: 5.7-14.8) in May 2022. Results of ANC1 serosurveillance provided prevalence estimates helpful in understanding this population case burden that was available through self-report and national case reports. To improve vaccine uptake, efforts to address fears and misconceptions regarding COVID-19 vaccines are needed.

BACKGROUND: Recent studies point to the need to incorporate the detection of non-falciparum species into malaria surveillance activities in sub-Saharan Africa, where 95% of the world's malaria cases occur. Although malaria caused by infection with Plasmodium falciparum is typically more severe than malaria caused by the non-falciparum Plasmodium species P. malariae, P. ovale spp. and P. vivax, the latter may be more challenging to diagnose, treat, control and ultimately eliminate. The prevalence of non-falciparum species throughout sub-Saharan Africa is poorly defined. Tanzania has geographical heterogeneity in transmission levels but an overall high malaria burden. METHODS: To estimate the prevalence of malaria species in Mainland Tanzania, we randomly selected 1428 samples from 6005 asymptomatic isolates collected in previous cross-sectional community surveys across four regions and analyzed these by quantitative PCR to detect and identify the Plasmodium species. RESULTS: Plasmodium falciparum was the most prevalent species in all samples, with P. malariae and P. ovale spp. detected at a lower prevalence (< 5%) in all four regions; P. vivax was not detected in any sample. CONCLUSIONS: The results of this study indicate that malaria elimination efforts in Tanzania will need to account for and enhance surveillance of these non-falciparum species.

In designing mass drug administration (MDA) campaigns, it is imperative to consider contextual factors that affect uptake of the intervention, including acceptability, cost, feasibility, and health system considerations, to ensure optimal coverage. We reviewed the literature on contextual factors influencing MDA delivery to provide programs with information to design a successful campaign. From 1,044 articles screened, 37 included contextual factors relevant to participants' values and preferences, drivers of MDA acceptability, health equity concerns, financial and economic aspects, and feasibility barriers; 13 included relevant modeling data. Key findings were abstracted by two reviewers and summarized. No studies directly assessed values or direct health equity concerns with respect to MDA, which represents an evidence gap as unequal distributions of effects and factors that impact participant acceptability and program feasibility must be considered to ensure equitable access. Participant acceptability was the most widely surveyed factor, appearing in 28 of 37 studies; perceived adverse events were a frequently noted cause of nonparticipation, mentioned in 15 studies. Feasibility considerations included when, where, and how drugs will be delivered and how to address pregnant women, as these can all have substantial implications for participation. Mass drug administration costs (∼$1.04 to $19.40 per person per round) are driven primarily by drug prices, but the delivery mechanism can have varying costs as well, and integration with other interventions may provide cost savings. Both programmatic goals and sociopolitical and economic contexts must be carefully considered before embarking on an MDA program to ensure programmatic success.

Recent studies point to the need to incorporate non-falciparum species detection into malaria surveillance activities in sub-Saharan Africa, where 95% of malaria cases occur. Although Plasmodium falciparum infection is typically more severe, diagnosis, treatment, and control for P. malariae, P. ovale spp., and P. vivax may be more challenging. The prevalence of these species throughout sub-Saharan Africa is poorly defined. Tanzania has geographically heterogeneous transmission levels but an overall high malaria burden. In order to estimate the prevalence of malaria species in Mainland Tanzania, 1,428 samples were randomly selected from 6,005 asymptomatic isolates collected in cross-sectional community surveys across four regions and analyzed via qPCR to detect each Plasmodium species. P. falciparum was most prevalent, with P. malariae and P. ovale spp. detected at lower prevalence (<5%) in all four regions. P. vivax was not detected. Malaria elimination efforts in Tanzania will need to account for these non-falciparum species.

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.

Malaria remains a significant cause of morbidity and mortality, even in low-transmission settings. With the advent of longer acting, more effective, and well-tolerated antimalarials, there is renewed interest in the efficacy of mass drug administration (MDA) to accelerate to elimination. We conducted a systematic review and meta-analysis to assess the efficacy of MDA to reduce the incidence and prevalence of Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) infection. From 1,044 articles screened, 14 articles, including 10 randomized controlled trials (RCTs), were identified. Five included data on Pf only; five included Pf and Pv. Two of the Pf studies were conducted in areas of high-moderate transmission, the remainder were in areas of low-very low transmission. In higher transmission areas, MDA reduced incidence of Pf parasitemia (rate ratio = 0.61, 95% CI: 0.40-0.92; moderate certainty) 1 to 3 months after drug administration; no significant effect of MDA on Pf parasitemia prevalence was detected 1 to 3 months post-MDA (risk ratio [RR] = 1.76, 95% CI: 0.58-5.36; low certainty). In lower transmission settings, both incidence and prevalence of Pf parasitemia were reduced 1 to 3 months post-MDA (rate ratio = 0.37, 95% CI: 0.21-0.66; RR = 0.25, 95% CI: 0.15-0.41, respectively). Pv prevalence was reduced 1 to 3 months post-MDA (RR = 0.15, 95% CI: 0.10-0.24); there were no RCTs providing data on incidence of Pv. There was no significant effect of MDA at later time points. MDA may have short-term benefits; however, there was no evidence for longer term impact, although none of the trials assessed prolonged interventions.

Malaria in pregnancy (MiP) intervention coverage, especially intermittent preventive treatment in pregnancy (IPTp), lags behind other global malaria indicators. In 2020, across Africa, only 32% of eligible pregnant women received at least three IPTp doses, despite high antenatal care attendance. We conducted a secondary analysis of data collected during outreach, training, and supportive supervision visits from 2019 to 2020 to assess quality of care and explore factors contributing to providers' competence in providing IPTp, insecticide-treated nets, malaria case management, and respectful maternity care. Data were collected during observations of provider-patient interactions in six countries (Cameroon, Cote d'Ivoire, Ghana, Kenya, Mali, and Niger). Competency scores (i.e., composite scores of supervisory checklist observations) were calculated across three domains: MiP prevention, MiP treatment, and respectful maternity care. Scores are used to understand drivers of competency, rather than to assess individual health worker performance. Country-specific multilinear regressions were used to assess how competency score was influenced by commodity availability, training, provider gender and cadre, job aid availability, and facility type. Average competency scores varied across countries: prevention (44-90%), treatment (78-90%), and respectful maternity care (53-93%). The relative association of each factor with competency score varied. Commodity availability, training, and access to job aids correlated positively with competency in multiple countries. To improve MiP service quality, equitable access to training opportunities for different cadres, targeted training, and access to job aids and guidelines should be available for providers. Collection and analysis of routine supervision data can support tailored actions to improve quality MiP services.

Malaria remains a leading cause of childhood morbidity and mortality in sub-Saharan Africa, particularly among children under 5 years of age. To help address this challenge, the WHO recommends chemoprevention for certain populations. For children and infants, the WHO recommends seasonal malaria chemoprevention (SMC), perennial malaria chemoprevention (PMC; formerly intermittent preventive treatment in infants [IPTi]), and, more recently, intermittent preventive treatment in school children (IPTsc). This review describes the contextual factors, including feasibility, acceptability, health equity, financial considerations, and values and preferences, that impact implementation of these strategies. A systematic search was conducted on July 5, 2022, and repeated April 13, 2023, to identify relevant literature. Two reviewers independently screened titles for eligibility, extracted data from eligible articles, and identified and summarized themes. Of 6,295 unique titles identified, 65 were included. The most frequently evaluated strategy was SMC (n = 40), followed by IPTi (n = 18) and then IPTsc (n = 6). Overall, these strategies were highly acceptable, although with IPTsc, there were community concerns with providing drugs to girls of reproductive age and the use of nonmedical staff for drug distribution. For SMC, door-to-door delivery resulted in higher coverage, improved caregiver acceptance, and reduced cost. Lower adherence was noted when caregivers were charged with giving doses 2 and 3 unsupervised. For SMC and IPTi, travel distances and inclement weather limited accessibility. Sensitization and caregiver education efforts, retention of high-quality drug distributors, and improved transportation were key to improving coverage. Additional research is needed to understand the role of community values and preferences in chemoprevention implementation.

Seasonal malaria chemoprevention (SMC) for children under 5 years of age for up to four monthly cycles during malaria transmission season was recommended by the WHO in 2012 and has been implemented in 13 countries in the Sahel, reaching more than 30 million children annually. Malaria control programs implementing SMC have asked the WHO to consider expanding the age range or number of monthly cycles. We conducted a systematic review and meta-analysis of SMC among children up to 15 years of age and up to six monthly cycles. Twelve randomized studies were included, with outcomes stratified by age (< 5/≥ 5 years), by three or four versus five or six cycles, and by drug where possible. Drug regimens included sulfadoxine-pyrimethamine + amodiaquine, amodiaquine-artesunate, and sulfadoxine-pyrimethamine + artesunate. Included studies were all conducted in Sahelian countries in which high-grade resistance to sulfadoxine-pyrimethamine was rare and in zones with parasite prevalence ranging from 1% to 79%. Seasonal malaria chemoprevention resulted in substantial reductions in uncomplicated malaria incidence measured during that transmission season (rate ratio: 0.27, 95% CI: 0.25-0.29 among children < 5 years; rate ratio: 0.27, 95% CI: 0.25-0.30 among children ≥ 5 years) and in the prevalence of malaria parasitemia measured within 4-6 weeks from the final SMC cycle (risk ratio: 0.38, 95% CI: 0.34-0.43 among children < 5 years; risk ratio: 0.23, 95% CI: 0.11-0.48 among children ≥ 5 years). In high-transmission zones, SMC resulted in a moderately reduced risk of any anemia (risk ratio: 0.77, 95% CI: 0.72-0.83 among children < 5 years; risk ratio: 0.70, 95% CI: 0.52-0.95 among children ≥ 5 years [one study]). Children < 10 years of age had a moderate reduction in severe malaria (risk ratio: 0.53, 95% CI: 0.37-0.76) but no evidence of a mortality reduction. The evidence suggests that in areas in which sulfadoxine-pyrimethamine and amodiaquine remained efficacious, SMC effectively reduced malaria disease burden among children both < 5 and ≥ 5 years old and that the number of cycles should be commensurate with the length of the transmission season, up to six cycles.

BACKGROUND: Children in Kenya spend a substantial amount of time at school, including at dawn and dusk when mosquitoes are active. With changing vector behaviour towards early morning biting, it is important to determine whether there is an additional risk of transmission in schools. This study sought to understand whether late morning biting by Anopheles funestus, previously documented in households in western Kenya, was replicated in schools. METHODS: From the 4th to the 6th of August 2023, human landing collections were conducted hourly in four schools in Alego Usonga sub-County, Siaya County. The collections were conducted in and outside five classrooms in each school and ran for 17 h, starting at 18:00 until 11:00 h the next morning. RESULTS: Anopheles funestus was the predominant species collected, forming 93.2% (N = 727) of the entire collection, with peak landing between 06:00 and 07:00 h and continuing until 11:00 h. More than half of the collected An. funestus were either fed or gravid, potentially indicative of multiple bloodmeals within each gonotrophic cycle, and had a sporozoite rate of 2.05%. CONCLUSION: School children spend up to 10 h of their daytime in schools, reporting between 06:00 and 07:00 h and staying in school until as late as 17:00 h, meaning that they receive potentially infectious mosquito bites during the morning hours in these settings. There is a need to consider vector control approaches targeting schools and other peridomestic spaces in the morning hours when An. funestus is active.

Malaria is a serious and potentially fatal disease transmitted through the bite of an infective | female anopheline mosquito; pregnant people are more susceptible to malaria infection than nonpregnant people, and are at risk of significant adverse consequences for both mother and infant.1 | | These include maternal anemia, fetal growth retardation, stillbirth, premature birth, and low | birthweight.2 | Rarely, malaria can be transmitted congenitally from mother to fetus or to the | neonate at birth. Globally, it is estimated that over 13 million pregnancies were affected by | malaria in 2021, leading to an estimated 505,000 infants born with low birth weight.3 While | malaria in pregnancy is rarely seen in the United States, it nonetheless occurs, with 19 cases | among pregnant women (both travelers and refugees/immigrants) reported in the US in 2018, | 4 27 | in 2019 (Mace, unpublished data), and 8 in 2020 (Mace, unpublished data), and needs to be | recognized and treated quickly to prevent adverse effects to the mother and infant.

Intermittent preventive therapy during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended in areas of moderate to high malaria transmission intensity. As a result of the increasing prevalence of SP resistance markers, IPTp-SP was withdrawn from Rwanda in 2008. Nonetheless, more recent findings suggest that SP may improve birthweight even in the face of parasite resistance, through alternative mechanisms that are independent of antimalarial effects. The prevalence of single nucleotide polymorphisms in Plasmodium falciparum dihydropteroate synthase (pfdhps) and dihydrofolate reductase (pfdhfr) genes associated with SP resistance among 148 pregnant women from 2016 to 2018 within Rwanda's Southern Province (Huye and Kamonyi districts) was measured using a ligase detection reaction-fluorescent microsphere assay. The frequency of pfdhps K540E, A581G, and the quintuple (pfdhfr N51I + C59R + S108N/pfdhps A437G + K540E) and sextuple (pfdhfr N51I + C59R + S108N/pfdhps A437G + K540E + A581G) mutant genotypes was 90%, 38%, 75%, and 28%, respectively. No significant genotype difference was seen between the two districts, which are approximately 50 km apart. Observed agreements for matched peripheral to placental blood were reported and found to be 207 of 208 (99%) for pfdhfr and 239 of 260 (92%) for pfdhps. The peripheral blood sample did not miss any pfdhfr drug-resistant mutants or pfdhps except at the S436 loci. At this level of the sextuple mutant, the antimalarial efficacy of SP for preventing low birthweight is reduced, although overall SP still exerts a nonmalarial benefit during pregnancy. This study further reveals the need to intensify preventive measures to sustain malaria control in Rwanda to keep the overall incidence of malaria during pregnancy low.