Objectives: To determine whether malaria epidemics in the Solomon Islands are related to the El Niño Southern Oscillation, rainfall and other hydro-climatic variables, and to determine if such as relationship can be used as an early warning system for predicting heightened risk of a malarial epidemic and therefore in assisting targeted control strategies.

Retrospective analysis of confirmed and unconfirmed cases of malaria in relation to El Niño and rainfall data will be carried out. Analysis of confirmed and unconfirmed cases of malaria is necessary to isolate the effect of control measures (e.g. Insecticide use) and any other policy changes from climate related factors. The hypothesis to be tested is that the incidence of malaria is related to periods of high rainfall (La Niña episodes), temperature and humidity. However, extreme rainfall events are likely to reduce malaria habitats by flushing of mosquito larvae from the river systems. This hypothesis will be tested through inclusion of rainfall thresholds (rainfall squared) in a multi-linear regression model. A further hypothesis, that malaria incidence may peak in years following an El Niño event (due to lower immunity of population to the parasite) will also be examined.