Efficacy of ivermectin for malaria vector control: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND

Despite global malaria control efforts, malaria continues to cause approximately 241-249 million cases and over 600,000 deaths annually. Ivermectin, a broad-spectrum antiparasitic drug with endectocidal activity against mosquitoes feeding on treated hosts, has been proposed as a potential malaria vector-control intervention.

OBJECTIVE

To systematically evaluate the effectiveness of ivermectin in reducing malaria transmission outcomes in adult populations, including malaria incidence, prevalence, mosquito mortality, and safety outcomes.

METHODS

Following PRISMA 2020 guidelines, we included randomized controlled trials (RCTs) and cluster-RCTs evaluating ivermectin compared with placebo, standard care, or non-ivermectin controls in adult populations. Outcomes included malaria incidence, prevalence, mosquito mortality, and adverse events.

RESULTS

Ten randomized trials involving 63,192 participants were included. Community-level analyses showed no significant reduction in malaria prevalence, with very wide confidence intervals reflecting substantial imprecision. Entomological trials demonstrated increased mosquito mortality following ivermectin exposure (RR 1.89; 95% CI 1.26-2.83), although heterogeneity was substantial (I2 > 97%). Across studies, ivermectin was generally well tolerated, with no significant increase in adverse events.

CONCLUSIONS

Current evidence does not demonstrate consistent reductions in malaria incidence or prevalence with ivermectin administration, although laboratory and experimental studies suggest mosquitocidal effects. Further large, well-designed cluster-randomized trials are required to determine whether ivermectin can contribute to malaria control strategies.