Climate Variability and Malaria Epidemiology in the Solomon Islands: Towards an Operational Malaria Early Warning System — ASN Events

Climate Variability and Malaria Epidemiology in the Solomon Islands: Towards an Operational Malaria Early Warning System (7781)

Isabelle Jeanne 1 , Jason A Smith 1 , Amanda Amjadali 1
  1. Bureau of Meteorology, Docklands, VIC, Australia

Malaria remains one of the leading causes of morbidity in the Solomon Islands despite the overall effectiveness of malaria control measures in the last decade. However, the success of these measures means that the Solomon Islands is now included amongst the World Health Organisation (WHO) list of malaria elimination countries. The Climate and Oceans Support Program in the Pacific (COSPPac) funded by AusAID and implemented by the Bureau of Meteorology is currently working to develop a climate-based Malaria Early Warning System (MEWS) for implementation in the Solomon Islands as part of its climate applications program.

Previous studies have shown that the epidemiology of malaria is strongly influenced by climate variables such as rainfall and temperature. However, due to the Solomon Islands tropical climate, temperature variations are relatively small always lie within a suitable range for the propagation of malaria vectors.  In contrast, rainfall in the Solomon Islands exhibits both high inter-seasonal and inter-annual variability particularly in the eastern and central provinces.  This indicates that rainfall is likely to be the most important climatic factor influencing the inter-annual and inter-seasonal variability of malaria incidence.

COSPPac has developed a broad-scale monthly statistical regression model linking rainfall, temperature and malaria incidence which demonstrates the strong relationship between climate and malaria in the Solomon Islands at a provincial scale. Initial analysis has demonstrated a one to two month time lag between the onset of the wet season (typically November – April) and the onset of peak malaria season (typically January – June) in the eastern and central provinces of the Solomon Islands as well as a strong correlation between below average rainfall in the wet season and above average malaria incidence in the corresponding malaria season. These results strongly affirm the feasibility of using rainfall as an indicator for the implementation of a climate-based MEWS.

However due to significant differences in rainfall, topography, land cover, epidemiological patterns and access to malaria control within each province, a higher spatial resolution model is required to develop a comprehensive and effective MEWS. A number of finer scale models are now being investigated to provide sub-provincial information about malaria incidence. In cooperation with local authorities including the Solomon Islands Meteorological Service (SIMS) and the National Vector-borne Disease Control Program (NVBDCP) it is anticipated that COSPPac will begin implementation of a prototype operational malaria early warning system covering the provinces of Temotu and Guadalcanal in the coming year.