West Nile Virus

West Nile virus can be dated back to 1937 in Uganda. It has appeared in other countries outside the United States including Egypt, and France. A major outbreak of the virus occurred in Israel in 1957. In North America, West Nile was first seen in the summer of 1999. Based on the recent patterns of the virus, it can be said that West Nile is firmly established here. The virus has become part of our landscape.

It is a virus noted to infect birds, horses, mosquitoes and humans. It is the mosquito that passes the virus on to other species. This usually occurs when the mosquito feeds on birds infected with the virus, and then goes on to bite another animal or human. At present, nothing suggests that West Nile can be spread via person-to-person or animal-to-person contact. Humans do not build up enough of the virus to pass it on to others. The virus has been documented in 45 states, of which Florida is one.

A strong sign that the West Nile virus is on an upsurge is the sighting of dead birds in the area. Monitoring of the virus can be supported by reporting the presence of the dead birds to the Florida Fish and Wildlife Conservation Commission website at www.wildflorida.org/bird/. Horses that are infected with West Nile Virus will often present with neurological signs.

As a state, Florida posted 28 “laboratory-positive human cases” of West Nile in year 2002 accounting for less than 1% of all cases and deaths. Only 2 deaths resulted. One case of human infection was reported in Orange County in 2002. In 2003, 64 cases of encephalitis due to West Nile virus and 30 cases of West Nile virus fever were reported statewide.

Humans infected with the virus usually experience mild to no symptoms. However some individuals have been severely ill, with associated deaths. Although it is rare for humans to become ill from the virus, residents should do what they can to reduce their chances of becoming infected and hence ill.

Practices to seriously consider:

• Eliminate standing water from residences, including old tires, bird baths for example. This eliminates a place for mosquitoes to lay their eggs.
• Stay indoors from early evening to dawn. Most bites from mosquitoes occur during these times.
• Use repellents with DEET when you are outside. Look for at least 10% DEET- N,N, diethyltoluamide on the label for great protectiveness. More than 32% DEET is of no additional value. DEET is deemed safe when used according to manufacturer’s directions.
• Long sleeve shirts and pants are advisable and should also be sprayed with insect repellant. DEET is effective on clothing until laundered.
• If there is an organized mosquito control program in your area, find out more information through them or visit the CDC website at http://www.cdc.gov/ncidod/dvbid/westnile/index.htm