The impact of climate change on West Nile Virus transmission in South Africa by 2040: application of an Ecosystem Based Approach

A West Nile Virus (WNV) outbreak in South Africa would be difficult for public health authorities to control because (1) it is not restricted to current malaria risk areas, (2) has no vaccine for people and (3) is not surveyed mostly due to its asymptotic nature in people.
We assessed the potential impact of climate change on the WNV transmission for 2050 in South Africa by applying an Ecosystem Based Approach and land cover change modeling.
Major environmental, climatic and social indicators that influence vector and host behavior in the WNV transmission cycle were integrated in a GIS environment and Climate Data Science toolbox (Species Distribution Model – SDM).
Hazard and vulnerability maps were created and combined to create risk maps that highlighted the country’s risk to the WNV currently and in 2050 under SSP2-2.4 and SSP5-8.5 scenarios.

The results indicate that climate change has minor positive and negative impacts regionally while the persistence of risk remains in several urban cities and municipalities, along the coastline and in the central plateau. As a hazard, the presence of WNV is very high across the country while vulnerable regions are focused around urban areas. The province of Gauteng is of most concern of a WNV outbreak and the Northern Cape is of least concern.