Impact of drought on vector-borne diseases – how does one manage the risk?

ObjectivesThis article aimed to review all literature on drought and vector-borne disease to enable an assessment of the possible impact of drought on the changing risk of vector-borne diseases in the UK.Study designA systematic literature review was performed.MethodsUsing a search strategy developed from a combination of terms for drought and selected outcomes, the authors systematically reviewed all available literature from 1990 to 2012 on the impact of drought on vector-borne diseases. The following databases were searched: PubMed, Web of Science, and EMBASE. After reviewing the abstracts, 38 articles were found to fit the inclusion and exclusion criteria.ResultsEvidence found drought followed by re-wetting can have a substantial effect on water table levels, vegetation, and aquatic predators; all factors which influence mosquito populations. Several studies found an association between a drought during the previous year and West Nile virus incidence. Urban mosquito vectors of dengue virus and chikungunya virus are adaptable by nature and are able to exploit a multitude of additional aquatic habitats created as a response to drought (i.e. water storage containers). Tick populations are likely to be negatively affected by drought as they are dependent upon high levels of humidity and soil moisture.ConclusionsFurther research is needed to identify public health interventions and environmental control measures for an invasive mosquito problem or arthropod-borne disease outbreak in the UK.