Description

Rift Valley fever (RVF) is a viral disease that affects primarily livestock and people. It is transmitted by several means, including the bites of mosquitoes and other biting insects, and percutaneous inoculation or inhalation of aerosols from contaminated blood or fluids of infected animals.

Occurrence

Occasionally, outbreaks occur involving large numbers of human cases, for example, in the Nile Delta, Egypt (1978 and 1993), and the lower Senegal River basin of Mauritania (1987). A large epidemic also occurred in Kenya and Tanzania in 1997 and 1998. A recent outbreak (2000) of RVF occurred in southwestern Saudi Arabia and Yemen with a strain of RVF closely related to that of the 1997-1998 strain. This represented the first spread of the virus outside Africa, demonstrating its potential for spread to unaffected regions elsewhere in the tropics.

Risk for Travelers

The risk of RVF infection to people who travel to endemic areas is generally low. Risk factors for acquisition of RVF include exposure to the blood or tissues of sick animals, or exposure to infected mosquitoes.

Preventive Measures

No vaccine is available for human use. An inactivated and a live, attenuated vaccine (MP-12) are currently under evaluation for use in humans, but have not yet been approved by the U.S. Food and Drug Administration. Travelers should be advised that they can reduce their risk of exposure by avoiding contact with livestock and minimizing their exposure to arthropod bites by using permethrin-impregnated bednets and insect repellents.

© National Center for Infectious Diseases - Center for Disease Control