Detection of Rift Valley Fever Virus in Aedes (Aedimorphus) durbanensis, South Africa

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 is closely related to two isolates from the earliest outbreaks, which occurred in central South Africa more than 60 years ago, indicating long-term endemicity in the region. Further research is required to understand the eco-epidemiology of RVFV and the vectors responsible for its circulation in the eastern tropical coastal region of southern Africa.

Automated summary

Rift Valley fever virus (RVFV) is a mosquito-borne, zoonotic phlebovirus-causing disease that affects domestic ruminants and humans in certain regions of Africa, the Arabian Peninsula, and Indian Ocean islands. This study tested mosquitoes collected in Ndumo, South Africa and found RVFV in a single pool of Aedes (Aedimorphus) durbanensis, suggesting its potential role as a vector in this region. Phylogenetic analysis revealed a close relationship between the identified virus and isolates from earlier outbreaks in the central South Africa, indicating long-term endemicity in the area. Further research is needed to understand the eco-epidemiology of RVFV and its associated vectors in the eastern tropical coastal region of southern Africa.