Miami baby possibly USA's 1st case of West Nile virus

Mar 22 2005

West Nile Virus is a flavivirus commonly found in Africa, West Asia, and the Middle East and is related to the St. Louis encephalitis virus found in the United States. Preliminary tests suggest a 14-month-old baby hospitalized in Miami may be the nation's first case of West Nile virus this year.

Doctors at Baptist Hospital have forwarded blood samples to the state's Jacksonville laboratory, where any West Nile diagnosis in Florida must be confirmed.

The the mosquito-borne disease, which usually does not appear until early summer is usually spread by the bite of an infected mosquito. Mosquitoes are carriers that become infected when they feed on infected birds. Infected mosquitoes can then spread West Nile to humans and other animals when they bite, according to the U.S. Centres for Disease Control and Prevention; the best way to avoid West Nile is to stay indoors at dusk and dawn, wear long clothing, use insect repellent containing DEET, and rid outdoor areas near the home of standing water, where mosquitoes breed.In its most severe form the disease is sometimes called “neuroinvasive disease” because it affects a person’s nervous system. Specific types of neuroinvasive disease include: West Nile encephalitis, West Nile meningitis or West Nile meningoencephalitis. Encephalitis refers to an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord, and meningoencephalitis refers to inflammation of the brain and the membrane surrounding it. West Nile Fever is another type of illness that can occur in people who become infected with the virus. It is characterized by fever, headache, tiredness, aches and sometimes rash. Although the illness can be as short as a few days, even healthy people have been sick for several weeks.

CDC scientists believe the virus has probably been in the eastern U.S. since the early summer of 1999, possibly longer.One species of mosquitoes found to carry West Nile virus is the Culex species which survive through the winter, or "overwinter," in the adult stage. That the virus survived along with the mosquitoes was documented by the widespread transmission the summer of 2000.

The West Nile virus appears to now be permanently established in the Western Hemisphere and West Nile encephalitis cases occur primarily in the late summer or early fall. In the southern climates where temperatures are milder, West Nile virus can be transmitted year round.