Influence of climatic factors on the incidence of dengue and malaria in Burkina Faso: an ecological study

nfluence du climat sur l’incidence de la dengue et du paludisme

Abstract

Introduction: Dengue and malaria are vector-borne diseases that are endemic and epidemic in Burkina Faso. This study aimed to assess the influence of climate on malaria and dengue fever in the cities of Ouagadougou and Bobo-Dioulasso. Methodology: It was an exploratory time series analysis using data from the SNIS and the General Directorate of Meteorology. ARIMA models were used to describe the trend of dengue fever and malaria from 2013 to 2016.
Results: From 2014 to 2016, 4287 cases of dengue fever were reported in the city of Ouagadougou, where dengue followed a bimodal intra-annual trend in August and November. In the univariate analysis by ARIMA, no significant association at 5%
was found between climate and dengue. In total,3,621,668 malaria cases were reported at Ouagadougou, against 2,521,789 cases at Bobo-Dioulasso. Malaria followed an intra-annual bimodal trend in August and October in both cities. The univariate analysis by ARIMA found no significant association at 5% between malaria and climate in Ouagadougou. Temperature and relative humidity predicted malaria incidence in multivariate analysis. Plus 1% of humidity induced 2780 new cases and +1°C maximum temperature, 12833 new cases; +1°C minimum temperature resulted in a reduction of 13196 cases. In Bobo-Dioulasso, malaria was significantly associated with rainfall and humidity in univariate analysis. In the multivariate analysis by ARIMA, humidity significantly predicted malaria; +1% caused 400 malaria cases.
Conclusion: There was a differential influence of climate on vector-borne diseases depending on the climatic zone, commanding specific responses. Moreover, dengue fever surveillance needs to be improved in the two cities.