Detection of rift valley fever virus in Aedes (Aedimorphus) durbanensis, South Africa

Authors: VAN DEN BERGH, CARIEN - University Of Pretoria; THOMPSON, PETER - University Of Pretoria; SWANEPOEL, ROBERT - University Of Pretoria; ALMEIDA, ANTONIO - Universidade Nova De Lisboa; PAWESKA, JANUSZ - National Institute For Communicable Diseases (NICD); JANSEN VAN VUREN, PETRUS - National Institute For Communicable Diseases (NICD); Wilson, William - Bill; KEMP, ALAN - National Institute For Communicable Diseases (NICD); VENTER, ESTELLE - University Of Pretoria

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2022
Publication Date: 1/24/2022
Citation: Van Den Bergh, C., Thompson, P.N., Swanepoel, R., Almeida, A.P., Paweska, J., Jansen Van Vuren, P., Wilson, W.C., Kemp, A., Venter, E.H. 2022. Detection of rift valley fever virus in Aedes (Aedimorphus) durbanensis, South Africa. Pathogens. 11(2):125. https://doi.org/10.3390/pathogens11020125.
DOI: https://doi.org/10.3390/pathogens11020125

Interpretive Summary: In a study of the effects of the environment on mosquito-borne viruses in South Africa genetic material for Rift Valley fever virus was found. This virus is endemic in Sub-Saharan Africa and can cause lethal disease in animals and man. Genetic analysis revealed that this material was closely related to isolates of this virus found 60 years previously. This finding demonstrates the genetic stability of this virus in its endemic area.

Technical Abstract: Rift Valley fever virus (RVFV) is a mosquito-borne, zoonotic phlebovirus-causing disease in domestic ruminants and humans in Africa, the Arabian Peninsula and some Indian Ocean islands. Outbreaks, characterized by abortion storms and a high morbidity rate in newborn animals, occur after heavy and prolonged rainfalls favouring the breeding of mosquitoes. However, the identity of the important mosquito vectors of RVFV is poorly known in most areas. Mosquitoes collected in the Ndumo area of tropical north-eastern KwaZulu-Natal (KZN), South Africa were tested for RVFV nucleic acid using RT-PCR. The virus was detected in a single pool of unfed Aedes (Aedimorphus) durbanensis, indicating that this seasonally abundant mosquito species could serve as a vector in this area of endemic RVFV circulation. Phylogenetic analysis indicated the identified virus was closely related to two isolates from the earliest outbreaks in central South Africa more than 60 years previously, indicating long-term endemicity in the region. Further research is required into the eco-epidemiology of RVFV and the vectors responsible for its circulation in the eastern tropical coastal region of southern Africa.