Vaccination is not recommended for livestock although both live and inactivated vaccine are available. This is for two reasons. Firstly, the live vaccine retains some pathogenicity and is a known cause of abortions in livestock. In addition, there is a real possibility that mosquitoes may transmit the vaccine virus from inoculated animals to other species, including man, and thereby cause disease. Secondly, the use of either live or inactivated vaccine could mask or confuse detection of disease presence and would also make 'freedom from disease' certification for trade purposes impossible.
Vigilance is therefore the key to early warning, early reaction and control.
In a recently established technical cooperation programme with FAO, veterinary authorities in Mali, Senegal and Mauritania are increasing surveillance for early signs of Rift Valley fever by using sentinel herds where the risk is high. Every month, during the current rainy season, veterinary officers are visiting the selected sentinel herds of cattle and small ruminants to conduct clinical examination and take serum samples for laboratory diagnosis. Blood tests from animals in the Delta du Niger region of Mali have revealed that the disease is circulating within the sentinel herd. Although further investigation has so far not revealed any clinical signs among animals or humans, the presence of the disease at sub-clinical level reinforces the need for surveillance. If an outbreak occurs, early detection means earlier control of livestock movement, more effective quarantine and less risk of the disease spreading to other regions.