The role of El Niño southern oscillation (ENSO) on variations of monthly Plasmodium falciparum malaria cases at the cayenne general hospital, 1996-2009, French Guiana

BACKGROUND: Malaria remains a serious problem in French Guiana, which is at potential risk for drought linked with the El Niño Event and where there could be a risk of malaria epidemic after the onset of an El Niño event. METHODS: A time series analysis using ARIMA was developed to investigate temporal correlations between the monthly Plasmodium falciparum case numbers and El Niño Southern Oscillation (ENSO) as measured by the Southern Oscillation Index (SOI) at the Cayenne General Hospital between 1996 and 2009. RESULTS: The data showed a positive influence of El Niño at a lag of three months on P. falciparum cases (p < 0.001). The incorporation of SOI data in the ARIMA model reduced the AIC by 4%. CONCLUSIONS: Although there is a statistical link, the predictive value of ENSO to modulate prevention intervention seems marginal in French Guiana. However, additional work should refine the regional dependence of malaria on the ENSO state.