African drought monitoring and estimation of Malaria vulnerability

Malaria epidemics in several regions of Africa have exhibited a relationship with climate variability, particuarly in situations where a large excess of rainfall has followed an extended drought period. Although many factors influence the development of a malaria epidemic, the climatic relationship suggests that some measure of vulnerability to malaria may be provided by an analysis of ongoing drought. A further benefit may be obtained by combining the monitoring of drought with seasonal forecasts of large rainfall events.

Several issues combine to make this a difficult activity, however: 1. The drought severity thresholds for determining useful risk assessments are not well known, 2. The performance of seasonal probability forecasts for areas with vulnerability to malaria has not been established, 3. The requirement of near real-time monitoring severely limits the amount of climate data available for analysis, 4. The medical data for malaria is sparse in both space and time, even for historical analysis.

The initial thrust of IRI's efforts in this area is the provision (online and in near real-time) of a monthly, rainfall-only based estimate of drought and drought duration, alone and in combination with the IRI seasonal forecast. The thresholds used in defining risk areas are based on ongoing analysis of historical droughts and malaria outbreaks. As of the date of the workshop, this online product will have been produced for five months, so we will also be able to report on our experiences with the operational issues and our interactions with users of this product.