Rift Valley Fever

Rift Valley Fever



Rift Valley fever is a viral infection that primarily affects domesticated animals, chiefly sheep, cattle, goats, and camels, but may involve humans as well. Historically, the disease has been limited to Africa, but a major outbreak was recently reported from Saudia Arabia and Yemen, demonstrating the potential of Rift Valley fever to spread to other regions. The disease is usually transmitted by mosquitoes, but may also be acquired by direct exposure to infected animals or their tissues. Aerosol transmission has been documented. Most cases occur in people who work with livestock. Outbreaks typically occur at times of heavy rainfall, when mosquitoes proliferate. The incubation period ranges from two to six days. Initial symptoms may include fever, chills, muscle aches, backache, headache, nausea, vomiting, and light sensitivity. Most people recover uneventfully in four to seven days, but the course by be complicated by loss of vision (retinitis), liver inflammation (hepatitis), kidney failure, excessive bleeding (hemorrhage), inflammation of the brain (encephalitis), or death. Experimental evidence suggests an antiviral drug called ribavirin may be effective, but this has not yet been tested in humans. No vaccine is currently available. The best means of prevention is to follow insect protection measures and to wear gloves and protective garments when handling animal tissues or caring for infected patients. Strict barrier and respiratory precautions are essential when patients with suspected Rift Valley fever are admitted to the hospital.