Rift Valley Fever
Rift Valley Fever Causes
Rift Valley Fever is caused by the RVF virus, which is a member of the Phlebovirus genus (Bunyaviridae family). Human outbreaks are usually caused by mosquito bites or direct contact with infected goats, sheep, cattle, buffalo, and other livestock. RFV outbreaks commonly occur in sub-Saharan Africa, and occurrences of outbreaks in other regions are rare.
Rift Valley Fever Definition
Rift Valley Fever (RVF) is a type of viral zoonosis; meaning, it primarily affects domestic livestock, but can be transmitted to humans. It is most commonly spread among humans through bites of infected mosquitoes or direct contact with infected animals.
Rift Valley Fever Diagnosis
Rift valley fever may be suspected if a huge number of young livestock dies simultaneous with a lot of humans suddenly becoming ill. In animals, tissue biopsies can be done to determine the infection. Diagnosis in affected humans can include serology (screening for IgM antibodies) and virus isolation. Naturalization tests to determine leukocytosis, leukopenia, thrombocytopenia, or schistocytes in blood samples can be done to confirm diagnosis.
Rift Valley Fever Symptoms and Signs
In affected humans, Rift Valley Fever can manifest with a variety of symptoms. Most cases may be asymptomatic or present only with mild headaches, fever, myalgia, and liver abnormalities. At the onset, infected patients can suffer from generalized weakness, fever, nausea, backaches, and weight loss. Recovery typically takes 2-7 days from the onset of the disease. In less than two percent of cases, the disease can progress to inflammation of the brain (meningoencephalitis), hemorrhagic fever syndrome, or eye disorders. Approximately one percent of infected humans may die from severe complications. Among infected livestock, the percentage can be significantly higher.
Rift Valley Fever Treatment
There is currently no specific treatment for rift valley fever. Therapy of afflicted humans usually focuses on managing symptoms. Ribavirin and convalescent plasma are sometimes used as pharmacological interventions.