Changing patterns of Jhum cultivation in Tripura, India and their impact on malaria

Abstract

Background Tripura is hyperendemic for malaria and is one of the few states in India that still fall under Category 3 for malaria elimination (i.e., state annual parasite incidence (API) > 1, i.e., number of malaria cases per thousand inhabitants in a year). Tribal communities in Tripura are largely dependent on Jhum cultivation for their sustenance, and several studies have highlighted Jhum as a major risk factor for malaria. Methods To assess the relationship between Jhum distribution and malaria in Tripura, Jhum hotspots were identified from Landsat-8 OLI spectral images using the Normalized burn ratio index and compared with secondary data on malaria incidence and the state/district-wise total area under Jhum for the years 2017 and 2019. Results The study’s results show that between 2017 and 2019, the total area under Jhum reduced from 39.56 km2 to 27.4 km2, which was accompanied by a shift in several Jhum hotspots from Dhalai and North Tripura in 2017 to West Tripura in 2019. Malaria cases showed a strong correlation with Jhum production both at the district and state level, which was significant at the 95% confidence interval. Furthermore, a stronger correlation in 2019 indicated that the share of malaria cases in Jhum cultivators may be increasing. Conclusions The present study presents preliminary evidence based on secondary data analysis on the possible implications of Jhum cultivation for malaria epidemiology in an endemic north-eastern state of India. It is suggested that real-time evidence should be generated on malaria prevalence among Jhum cultivators and their families. Based on the evidence, future intervention strategies for the state should focus on the elimination of malaria risk from Jhum cultivators by minimizing outdoor exposure to malaria vectors and improving access to diagnostics and treatment.