Abstract
BACKGROUND: Rajasthan state of India is exhibiting diverse malaria transmission patterns shaped by its varied ecological landscapes. This study explores five decades (1975-2023) of malaria patterns in different ecogeographical regions of Rajasthan. METHODS: The four ecogeographical regions of Rajasthan, namely Desert, Aravalli, Gangetic plain, and Hadoti Plateau, were taken into consideration to identify spatio-temporal malaria trend, Anopheles species diversity, and insecticide susceptibility status of malaria vectors with public health insecticides. Additionally, correlation analysis between malaria incidence (API) and average annual rainfall was conducted to understand the climatic influence on transmission dynamics. RESULTS: Over five decades, Malaria peaked in 1976 and 1996, followed by a sharp decline post-2000. Median API ranged from 1 (Gangetic plain) to 1.93 (Hadoti Plateau), with frequent outbreaks in the Gangetic plain and Hadoti Plateau regions. Rainfall was positively correlated with API in Desert region (r = 0.39; p = 0.006) and Gangetic Plain (r = 0.35; p = 0.014) regions. Hadoti Plateau region showed a weak negative correlation with rains (r = -0.08; p = 0.58). Anopheles stephensi and Anopheles culicifacies were predominant vectors, resistant to organochlorides and organophosphates, but susceptible to synthetic pyrethroids. Aravalli showed the highest Plasmodium falciparum prevalence among all regions. DISCUSSION: The study highlights the need for region-specific vector control, real-time surveillance, and adaptive policies to tackle malaria challenges. High-risk areas like Aravalli and Hadoti Plateau require focused interventions combining community awareness, improved healthcare access, and climate-responsive strategies. Integrating ecological insights with innovative tools such as GIS mapping and interactive dashboards can enhance monitoring, guide targeted actions, and reduce vector density. These efforts are crucial to sustain progress and accelerate malaria elimination across the diverse ecological zones of Rajasthan.