An overview of arboviruses and bunyaviruses

Arboviruses belong to various families of viruses that are transmitted by arthropods, mainly mosquitoes and ticks. Arboviruses that cause human encephalitis in the United States are members of 3 main virus families: Togaviridae, Flaviviridae, and Bunyaviridae; they include St. Louis encephalitis (SLE), Western equine encephalitis (WEE), Eastern equine encephalitis (EEE), La Crosse virus (LAC), and other California serogroup viruses. In the United States, the incidence is usually 150 to 3,000 cases per year. Most infections are asymptomatic or may result in a nonspecific flu-like syndrome, but if clinical cases do occur, the consequences may be serious. Diseases caused by arboviruses include encephalitis, febrile diseases, and hemorrhagic fevers. Rapid serologic assays such as IgM-capture ELISA (MAC-ELISA) and IgG ELISA can be used soon after infection for diagnosis. There is no specific treatment and therapy is mainly supportive. Prevention includes vector control, educating the public to avoid high-risk areas, wearing protective clothing, and using DEET-containing insect repellents.