Pyrimethamine 25mg / Sulfadoxine 500mg tablets

Malaria remains a global health threat, with Plasmodium falciparum causing most deaths, especially in sub-Saharan Africa. Although artemisinin-based therapies reduce the burden, drug-resistant parasites threaten control efforts. Mapping the distribution and evolution of molecular resistance markers is vital for evidence-based strategies. This systematic review mapped the global distribution, pooled prevalence, and temporal trends of key P. falciparum antimalarial resistance markers. Following the PRISMA methodology (PROSPERO: CRD4202511098991), databases (PubMed, Web of Science, Scopus, and Google Scholar) and gray sources were searched (July 2005-July 2025). Data were extracted in Rayyan, assessed via the JBI prevalence tool, and analyzed using Python v3.13 for WHO regional distribution, temporal trends, and treatment outcome trends. Of the 1972 records, 261 studies from 64 countries qualified for inclusion in this review. The pooled prevalence was highest for pfdhfr (85.7%), followed by pfcrt (78.0%), pfdhps (73.7%), pfmdr1 (60.5%), and pfk13 (45.0%). High heterogeneity (I2 > 95%) and rising pfk13 since 2012 highlight emerging artemisinin resistance, while persistent pfdhfr/pfdhps mutations show that ongoing sulfadoxine-pyrimethamine (SP) pressure on P. falciparum drug resistance, decreased parasite clearance, and treatment failure remain widespread and evolving in Africa. Integrating molecular surveillance into national malaria programs is essential to guide treatment modalities and support progress toward malaria elimination.

Abstract licence: CC BY

BackgroundMalaria remains a significant public health challenge in Nigeria, accounting for a substantial proportion of global malaria cases and deaths. Although artemisinin-based combination therapies (ACTs) are the recommended first-line treatments, resistance to antimalarial drugs continues to threaten malaria control efforts. This systematic review provides an overview of the molecular surveillance of antimalarial drug resistance in Nigeria, aiming to identify prevalent resistance markers and inform future research and policy directions.MethodsA systematic search was conducted using databases including PubMed, ScienceDirect, Ovid and Scopus. Studies published from 2010 to 2024 and focused on key resistance markers such as Pfcrt, Pfmdr, Pfdhfr, Pfdhps, and Pfk13 genes were included.ResultsA total of 26 studies met the inclusion criteria, revealing a high overall prevalence of mutations associated with resistance to chloroquine and sulfadoxine-pyrimethamine, particularly in Pfcrt and Pfdhfr genes. Although mutations associated with artemisinin resistance in the Pfk13 gene were less common, their presence warrants attention for future surveillance. Within this overall pattern, regional disparities were evident, with generally lower Pfcrt prevalence in northern Nigeria compared to the south, though levels varied across locations and time periods.ConclusionRegional variability in CQ resistance mutations has been observed across Nigeria, with lower prevalence in some northern states but persistence in others. CQ may be reconsidered as an alternative to ACTs only in areas where resistance remains consistently low, contingent upon clinical trials confirming efficacy and safety, and accompanied by molecular surveillance to guide targeted policy decisions.

Abstract licence: CC BY-NC-ND

Summary Each year, over 50 million children receive preventive malaria treatment. However, to date there has been no consensus on the most effective antimalarial drugs to use, especially given geographic differences in drug resistance. Here, we conduct a systematic review comparing the effectiveness of the most commonly used antimalarial chemopreventive regimen, sulfadoxine-pyrimethamine plus amodiaquine (SP+AQ), with other antimalarial drugs in preventing new infections. We searched MEDLINE, Embase, Global Health, PubMed and WWARN clinical trial databases until 06 December 2025 for studies satisfying the inclusion criteria. Studies were included if they were peer-reviewed, randomised-controlled studies in Africa, measuring incidence of infection or clinical episodes of Plasmodium falciparum malaria for at least 28 days post-treatment. We also compiled data on the prevalence of markers of resistance in the parasite dhfr, dhps and mdr1 genes in the study areas. We conducted meta-analyses of incidence rates, with subgroup analyses by drug resistance levels. This review is registered on PROSPERO (CRD42024577149). We identified 27 studies representing 38,252 participants in 32 sites across 13 countries. In pooled analysis, SP+AQ reduced incidence of malaria by 54.6% (95% CI: 33.8–68.8%) compared to SP alone, including significantly outperforming SP even in areas with low SP resistance. These findings suggest that countries currently using SP alone for chemoprevention should consider switching to SP+AQ. Where AQ resistance remains low, available evidence suggests SP+AQ remains efficacious for malaria chemoprevention. SP+AQ was comparable to the artemisinin-based treatment, dihydroartemisinin-piperaquine across all studies (incidence rate ratio 0.93; 95% CI 0.78- 1.11). By resistance levels, SP+AQ had slightly higher efficacy in areas with low SP and AQ resistance but had comparable or slightly lower efficacy in areas with higher resistance. Using artemisinin-based treatments for chemoprevention must be balanced against the risk of worsening artemisinin resistance in Eastern and Southern Africa. This study was funded by the UK Royal Society.

Abstract licence: CC BY-NC-ND

This study aimed to evaluate the efficacy of DHP as an alternative to SP for the prevention of malaria and malaria-related complications during pregnancy. A systematic review and meta-analysis were conducted using pooled effect sizes extracted from published studies. Compared to SP, DHP significantly reduced maternal malaria infection by 78% (RR 0.22, 95% CI: 0.09-0.55), placental malaria infection by 73% (RR 0.27, 95% CI: 0.08-0.98), and maternal anaemia by 16% (RR = 0.84, 95% CI: 0.79-0.89). Women randomized to the DHP arm had a 28% lower risk of foetal loss (RR 0.72, 95% CI: 0.40-1.31), a 4% lower risk of low birth weight (RR 0.96, 95% CI: 0.69-1.32), and a 17% lower risk of preterm births compared with those receiving SP (RR 0.83, 95% CI: 0.61-1.13), though the reduction was not statistically significant. Therefore, DHP appears to be more effective than SP as IPTp therapy for reducing maternal malaria infection, placental malaria infection, and maternal anaemia. However, this study does not significant advantage of DHP over SP in reducing adverse birth outcomes.

Abstract licence: CC BY-NC-ND