Role of Vectors and Climate Change on the Epidemiology of Rift Valley Fever

Abstract

Rift Valley fever (RVF) is an emerging viral zoonosis that causes frequent outbreaks in east Africa and on the Arabian Peninsula. It’s caused by Rift Valley fever virus (RVFV) of genus phlebovirus, which is a high priority pathogen because of its economic and public health importance. It can cause miscarriage in pregnant animals and a high mortality in young animals and in human RVF causes a severe infl uenza like illness. The major outbreaks of the disease have been reported to occur throughout much of sub-Saharan Africa, Egypt, in the Middle East (Saudi Arabia and Yemen) and the island of Madagascar. Its occurrence is highly associated with the effect of the warm phase of the El Nino/Southern Oscillation (ENSO) phenomenon which resulted in abnormal heavy rainfall which in turn allow fl ooding of the vector’s habitat. Transmission of RVF during the endemic cycles requires the involvement of Aedes mosquito species which serve as the primary maintenance vectors of the disease. Infected Aedes species transmit the virus transovarially to their eggs. The egg of these endemic vectors remains viable during dry period for long periods. Then, following period of abnormally heavy rainfall fl ooding of their habitat occurs and the eggs start to hatch and then generating infected mosquito species. These hatched mosquito species start to disseminate the virus to nearby animals followed by other biting mosquito (Culex and Anopheles) which in turn feed on the blood of viremic animals and contribute to the epidemic transmission of virus, serve as secondary amplifi er of the virus. Immunization of animals, destruction of mosquitoes and restriction on the movement of animals during epizootic can help in the control of RVF. The likelihood of RVF global expansion is due to climate change and environmental modifi cation is an important issue. Thus, great focus is needed to deal on the infl uence of climate change on the vector population and their effect on the occurrence of the disease. Begna Bulcha Guta1, Mehari Tarafa2, Samson leta Regassa3* 123Department of Biomedical Science, Addis Ababa University, college of veterinary medicine, Bishoftu, Ethiopia. *Address for Correspondence Samson Leta Regassa, Department of Biomedical Science, Addis Ababa University, college of veterinary medicine.Bishoftu, Ethiopia. Email: samiwude@gmail.com Submission: 02 March, 2019 Accepted: 04 April, 2019 Published: 06 April, 2019 Copyright: © 2019 Regassa SL, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Review Article Open Access