Effect of temperature, rainfall and relative density of rodent reservoir hosts on zoonotic cutaneous leishmaniasis incidence in Central Tunisia

Abstract

Objective: To study the effect of climate variability and rodent density on the incidence of zoonotic cutaneous leishmaniasis (ZCL) in humans. Methods: We collected monthly ZCL human cases in primary health care facilities, in schools and in the community. We collected monthly climate parameters such as temperature, humidity, rainfall, wind direction and wind speed, and rodent density. We investigated the relationship between ZCL incidence and climate and environmental variables by univariate and different multivariable analysis (multiple linear regression, negative binomial regression and autoregressive integrated moving average). Results: The ZCL number peaked in October and November. In univariate analysis, positive associations were found for the maximum, mean and minimum temperatures lagged for three and six months, with higher correlation coefficient for the mean temperature lagged for six months (r = 0.837, P < 0.01). All multivariate analyses showed positive association between monthly ZCL incidence and the six months moving average temperature with higher correlation coefficients and very small significant level, whereas negative association was observed for the cumulative rainfall of the last year. Conclusions: This work showed a significant association between ZCL incidence and climate variables suggesting that ecological early warning system could be applied for ZCL.