The institutions said Thursday that the risk of the deadly disease occurring in eastern Africa in both humans and livestock is high due to favorable environmental conditions and increased movement of livestock and human beings.
"During the period March-May, heavy, prolonged and widespread rains triggered severe flooding in Ethiopia, Kenya, Somalia, Western Tanzania, Burundi and Rwanda creating a suitable environment for vector multiplication," the institutions said.
They added that extensive hotspots for vector multiplication are predicted in Kenya, Ethiopia, South Sudan, Somalia and Ethiopia while localized hotspots are predicted in Uganda, Sudan, Burundi and Tanzania.
"The suitable conditions for vector amplification are predicted to persist in the region due to favorable forecasts for June to August," the agencies warned, asking regional governments to enhance surveillance.
RVF is an endemic vector-borne zoonotic disease that is a threat to both humans and animals and is spread by mosquitoes.
According to experts, it is a complex disease, making monitoring of the risk and carrying out efficient control measures challenging.
Heavy rains and prolonged flooding increase habitat suitability for vector populations, leading to the hatching of RVF-competent mosquitoes (Aedes and Culex), thus influencing the risk of an outbreak.
The disease disrupts livestock industries, food security and the livelihood of the pastoralist communities, the FAO warned.