The climatic factors associated with incidence of Leptospirosis in Sri Lanka

Abstract

Leptospirosis is an endemic disease of public health importance in Sri Lanka. An ecological study was conducted to describe the association of selected climatic factors with district level incidence of Leptospirosis in Sri Lanka between 2008 and 2011. The factors selected were rainfall, rainy days, temperature and humidity. Districts were categorized in to districts reporting high, moderate and low incidence of Leptospirosis based on annual average incident rate of Leptospirosis. In general the present study did not find statistically significant correlation between climatic factors with district level Leptospirosis incidence, though a positive correlation between rainfall and incidence of Leptospirosis was found in majority of districts with high incidence of Leptospirosis. However, the observed correlation was statistically significant only in two districts. Sri Lanka is a country with minimal fluctuation of climatic factors (eg: temperature, humidity) among districts. It may have an impact on the poor correlation between climatic factors with incidence of Leptospirosis cases. Rainfall being positively correlated with Leptospirosis incidence in high incidence districts may suggest the rainfall to play a more important role in Leptospirosis epidemics than endemic transmission. Hence Public Health authorities need to strengthen control and preventive measures during the period of monsoon rains especially in districts with high incidence. Since this is an ecological study, further research is needed to assess the present study findings. DOI: http://dx.doi.org/10.4038/jccpsl.v19i2.7581 Journal of the College of Community Physicians of Sri Lanka 2014 June 19(2): 29-34