Analyses of ten-year malaria transmission dynamics in relation to meteorological variables in Jabi Tehnan District, Northwest Ethiopia

Abstract

Retrospective studies of malaria cases from health facilities and the impact of meteorological factors provide insight into the dynamics of malaria transmission and the effectiveness of malaria control interventions. This study aimed to analyze inter-annual and monthly trends in malaria cases and determine the correlations between meteorological variables and prevalence of malaria. Retrospective data on malaria cases were extracted from 11 health centres and 39 health posts in Jabi Tehnan district, northwest Ethiopia, for 10 years (July 2011–May 2021). Trends in monthly and annual malaria cases were analyzed and correlated with meteorological data. Of 1,500,868 individuals with febrile complaints examined at the health facilities in the district, 13.4% were diagnosed as clinical malaria cases. Furthermore, 12.6% of those with febrile symptoms had malaria confirmed with microscopy and with rapid diagnostic test (RDT). Plasmodium falciparum comprised 56.48%, with 36.56% P. vivax, and with 6.96% mixed (P.f + P.v) infections. There were significant variations in inter-annual and monthly malaria cases (P<0.001; P = 0.004, respectively). Malaria cases peaked in 2011–2013, and 2015–2016, with reduced and relatively lower malaria cases in 2017–2021. Two malaria peaks in May-June, and in October-November were recorded. Inter-annual and monthly malaria trends were closely correlated with relative humidity and average temperatures. Plasmodium falciparum was predominant compared to P. vivax. Understanding trends in malaria transmission in relation to climatic variables, and monitoring the effectiveness of malaria control interventions are needed to reduce malaria in the area.