A virus transmitted by mosquitoes that can cause severe cases of encephalitis. The majority of infections (8o percent) do not cause symptoms but, among people who are sick enough to require hospitalization, the death rate is higher than lo percent. Mild infections cause fever, fatigue, enlarged lymph nodes, eye pain, stomach pain, muscle ache, and headache. A rash may develop in children. A diagnosis of West Nile virus is made with blood tests. There is no specific antiviral therapy for the infection, but regular use of insect repellant can help prevent mosquito bites.
A mosquito-borne viral infection that is normally harmless to healthy people who, if infected, develop a mild influenza-like illness. However, if the elderly and those in poor health, particularly immunocompromised patients, are infected, they may develop fatal inflammation of the brain and spinal cord. In Israel in 2000, 12 people died and more than 155 survived an outbreak; and in New York in 1999, more than 60 people were infected, of whom six died. The disease is endemic in the Middle East and Africa, but has recently spread to parts of Europe, central Asia, Oceania and America. Mosquitoes bearing the flaviviridae-family virus usually contract it by biting infected poultry, but the infection has been found in mammals, such as cats, dogs and horses.
An arbovirus that primarily infects birds but can be transmitted by mosquito bite to humans and other animals. Since West Nile virus was identified in the U.S. in 1999, it has produced a nationwide epidemic of encephalitis. Although infection is usually asymptomatic, signs and symptoms that are more likely to be observed in the very young, the very old, or the very sick include fever, headache, stiff neck, fatigue, loss of appetite, nausea or vomiting, muscle pain, aches, and weakness (“neuroinvasive” disease may produce an acute flaccid paralysis). Infection is occasionally fatal. Those over age 50 are at greatest risk for serious complications and death.
A virus closely associated with the Zika virus (ZIKV) that induces an illness resembling Zika fever. However, in certain cases, this virus can progress to encephalitis or meningitis.
This virus is transmitted to humans through mosquito bites after being initially contracted from infected animals or birds. In the majority of cases, individuals either experience no symptoms or exhibit flu-like symptoms. However, on rare occasions, a severe and potentially life-threatening illness may develop when the virus attacks the brain. This virus is prevalent in regions such as Africa, Eastern Europe, West Asia, the Middle East, and, starting in 1999, along the eastern coast of the United States.