The socioeconomic impacts of Rift Valley fever: A rapid review

Abstract

Rift Valley fever (RVF) is a neglected vector-borne disease which is endemic in many countries across Africa and has seen recent geographical expansions into the Arabian Peninsula. RVF can cause severe infections in both animals and humans. RVF infections in livestock can lead to mass fatalities. In humans, the symptoms are nonspecific and can often lead to misdiagnosis. However, a small proportion progresses to haemorrhagic infection with a significantly higher mortality rate. The culmination of this can cause severe socioeconomic impacts. This review aims to identify the main socioeconomic impacts caused by RVF outbreaks as well as existing knowledge gaps. Ninety-three academic and grey papers were selected, covering 19 countries and 10 methodological approaches. A variety of socioeconomic impacts were found across all levels of society: Livestock trade disruptions consequently impacted local food security, local and national economies. Most livestock farmers in endemic countries are subsistence farmers and so rely on their livestock for sustenance and income. RVF outbreaks resulted in a variety of socioeconomic impacts, e.g., the inability to pay for school fees. Main barriers to vaccine uptake in communities were lack of access, funds, interest along with other social aspects. The occupational risks for women (and pregnant women) are largely unknown. To our knowledge, this is the first review on RVF to highlight the clear knowledge gap surrounding the potential gender differences on risks of RVF exposure, as well as differences on occupational health risk in pastoral communities. Further work is required to fill the gaps identified in this review and inform control policies.

Fig 1. Illustrative flowchart of the data extraction.

Fig 2. Illustrates all the years RVF incidence has been reported.

The graph demonstrates RVF outbreaks are occurring at an increasing rate.

Fig 3. Illustrates the socioeconomic impacts of RVF outbreaks reported at farm, regional, and national levels.

The socioeconomic impacts were extracted from the studies included in this review and then grouped into the following categories: general impacts (green) to individuals that would be experienced across all levels of society, farm-level (pink), regional level (blue), and national level (purple). The dotted lines indicate inter-connectivity between levels and the straight lines connect the level of society to examples of socioeconomic impacts at the different levels.

Fig 4. Is an illustrative map of Africa and Southwest Asia.

The purple countries report endemic disease, orange countries report few cases and sporadic outbreaks, and grey countries the status of RVF is unknown. The dashed lines highlight the countries where economic impacts have been found in this review. The endemicity data is based on the data from epidemiological update and risk of introduction to Europe [74]. The shapefiles to create the map were downloaded from DIVA-GIS website (https://diva-gis.org/). Map was created using tools provided in ArcGIS 10.8.1. (Esri Inc, 2016).