Rift Valley Fever (RVF) is caused by a zoonotic arbovirus that is endemic to Eastern and Southern Africa. It has also been reported in West and North Africa, Madagascar and the Arabian Peninsula. The virus is transmitted by mosquitoes and humans may also be infected with RVF while handling blood or other animal body fluids.
The disease affects cattle, sheep, goats, several rodents, wild ruminants, buffaloes, antelopes, among others. RVF virus regularly circulates in endemic areas between wild ruminants and haematophagous mosquitoes. The disease is usually unapparent in wild species of animals due to their lower susceptibility.
Certain Aedes species act as reservoirs for RVF virus during inter-epidemic periods. Increased precipitation or flooding in dry areas leads to an explosive hatching of mosquito eggs, many of which harbour RVF virus
The disease is characterized by a high fever lasting 24–96 hours, nasal discharge and excessive salivation, anorexia, weakness, bloody/fetid diarrhoea, bloody in natural cavities, fall in milk yield, abortion rate which may reach 85% in the herd. There is not any specific treatment for RVF.
The presence of RVF in Rwanda was confirmed in 2013, and regular vaccination campaigns started therefore. This fiscal year 2021-2021, Rwanda Agriculture and Animal Resources Development Board (RAB) plans to vaccinate more than 365,000 animals, especially in districts bordering Akagera and Nyabarongo rivers.
Containing the disease is effective through vaccinating susceptible animals in risk zone, controlling animal movements (extension of disease), maintaining hygiene in slaughterhouses, draining standing water to eliminate or reduce vectors, building the capacity of farm personnel, and clinical management of RVF cases.
The activity is expected to end in mid-November 2020.