Rift Valley fever (RVF) is a viral disease. RVF causes acute disease most commonly observed in domestic animals (such as cattle, buffalo, sheep, goats, and camels) and human. The disease is caused by the RVF virus (RVFV), a member of the genus Phlebovirus in the family Bunyaviridae.
RVF is mostly found in countries of sub-Saharan, Africa and in Madagascar. The first Rift Valley fever outbreak cases identified outside of Africa in 2000, in the regions of Saudi Arabia and Yemen. Several mosquito species act as vector for RVF. While mosquito suck the blood containing virus of the infected animal, and transmit the virus to other animals on which they subsequently feed. Some species of mosquitoes (Aedes, for example) are capable of transmitting the virus from infected female mosquitoes to offspring via its eggs. Mosquito eggs may survive up to several years in dry conditions. During periods of high rainfall and/or flooding the eggs hatch and there is an increase in the infection of animals on which these mosquitoes feed. Humans are may infected by the RVF virus with RVF by being bitten by infected mosquitoes, through contact with blood, other body fluids or tissues during killing, skinning and cutting of infected animals, or by consumption of raw milk or uncooked meat from infected animals. In humans symptoms of the RVF are, fever, weakness, myalgia, back ache, liver abnormalities. Severe complications develop in 1-4% of cases though most people recover within four to seven days. No human-to-human transmission has been documented. An inactivated vaccine has been developed for human use. However, this vaccine is not licensed and is not commercially available. Vaccines of RVF are under research.
Recently on 23 July, 2016 in China a 45 -year-old male affected by RVF. The National Health and Family Planning Commission of the People’s Republic of China assemble an expert group on 23 July to review the patient’s epidemiological history, clinical symptoms and laboratory results and it was deduced that the case is China’s first imported case of RVF. The patient is currently in serious condition.