Rift Valley fever (RVF) is a viral infection which primarily is seen in animals. However, it can cross over into humans, and is an example of a zoonotic disease. There are reservoirs of this disease in numerous African nations. Outbreaks of Rift Valley fever often occur after seasons of heavy rains, and cases have been documented as far north as the Middle East as a result of travel of infected people or animals and animal products which contain the virus.
The virus which causes Rift Valley fever is in the Phlebovirus genus. One very common mode of transmission is via insect vector. Insects such as mosquitoes which bite animals can pass the virus between animals and when the insects bite humans, they inject the virus into the human bloodstream. People can also get Rift Valley fever by handling infected animals and animal products such as meat and milk, and may pass the virus between each other as a result of poor hygiene such as failing to wash the hands after touching the nose.
The first sign of a Rift Valley fever outbreak is often a wave of spontaneous abortions among livestock, because the virus causes abortions in animals like cattle and goats. People exposed to the virus get sick within two to six days. In the most mild form, Rift Valley fever presents with flu like symptoms. The patient may feel nauseous and feverish for several days until the infection resolves, and then she or he should improve.
However, there are more serious forms of the disease. The ocular form attacks the eyes and can lead to blindness, for example, and Rift Valley fever can also cause meningitis and severe brain damage. Patients can also develop issues like chronic joint pain as a result of the infection. One particularly deadly variant is the hemorrhagic fever form of the virus, which causes death as a result of controllable bleeding, much of which is internal.
There is no cure for Rift Valley fever, although several companies have worked on developing a Rift Valley fever vaccine. Treatment focuses on providing supportive care to the patient to help him or her survive the acute phases of the infection, and on isolating people with active infections so that they cannot pass the virus on to others. During active outbreaks of Rift Valley fever, people are also encouraged to be careful about hygiene and to observe strict food safety precautions to reduce the risk of picking up the virus. However, this is not always possible, especially in remote regions which may lack the infrastructure to support better hygiene.