July 3, 2003

The season’s first cases of arboviral infection were reported in two people by the Houston Department of Health and Human Services (HDHHS) today. The cases include two adults, a female and a male from the north side of Houston (the Health Information Portability and Accountability Act, HIPAA, precludes further description of the patients.)

Arboviral infections are insect, usually mosquito, borne diseases that include West Nile virus and St. Louis virus. West Nile virus first appeared in Houston in 2002; St, Louis virus has infected local mosquitoes for several decades. West Nile virus and St. Louis virus may cause encephalitis. There were 81 confirmed cases of West Nile infection in Houston in 2002.

People become infected with West Nile virus or St. Louis virus when bitten by an infected mosquito. In Houston, the Culex mosquito is the carrier of both viruses. Feeding on infected birds infects mosquitoes. The Culex feeds from dusk to dawn and breeds primarily in storm sewers.

Symptoms of both infections include sudden onset of fever, nausea, headache, weakness, achiness, neck/back pain and altered mental status.

Houstonians are strongly recommended to take precautions to prevent mosquito bites:

• Wear mosquito repellent which contains the active ingredient DEET when outside in the evening and early mornings.
• Wear long sleeved shirts and pants when outside.
• Prevent mosquitoes from entering the home by securing doors and window screens; fill any gaps which could let mosquitoes in the house.

Prevent mosquito breeding:

• Keep lawn clippings and other waste out of the storm sewers.
• Prevent lawn sprinkler runoff into the streets.
• Clean out rain gutters around the house.
• Empty or remove water containers where mosquitoes may breed.

For more information about West Nile virus and other arboviral infections, go to www.houstonhealth.org.