Climate change and its impact on incidence of malaria in central India

Abstract

Background: Climate change is progressing globally and is likely to affect the human health in various ways. Transmission of vector borne disease like malaria is likely to be affected by changes in various climatic factors. Variable relationships of various climatic factors and the incidence of malaria are shown in different studies. In view of above, the study, a correlation analysis of past five years’ meteorological data of Bhopal city with incidence of malaria was conducted. Methods: The mean minimum, maximum and average temperature, mean total rainfall and relative humidity from the period of 1952-2002 and monthly meteorological data from the period of 2004-2008 was used to project climatic changes in Bhopal city of central India. Monthly incidence of total malaria positive cases, and Annual Parasite Incidence (API) was obtained from 2004-2008 and 1999-2003 for comparative analysis using statistical techniques. Results: Micro-climatic analysis of the city indicated a trend towards increase in monthly mean minimum temperature in the observation period as compared to last 50 years. So, the summers and winters were getting warmer with low precipitation and erratic pattern of rain fall over last five years which indicated a significant change in the climate of Bhopal that may be related to the changed incidence of diseases. The incidence of malaria, which was presumed to be more frequent during rainy season, was also showing its stronger impacts in early and late winters too. When minimum temperature increases in winter, the incidence of malaria was also increasing (r = .28). Conclusion: The incidence of malaria shows increase in central India mainly in winter season and may show upsurge of malaria cases in newer and colder regions globally due to climate becoming more conducive for the parasite and vector ultimately depending upon effectiveness of adaptation and mitigation strategies for climate change.