West Nile Virus Plagues Dallas

Symptoms of West Nile virus usually appear 3 to 14 days after infection, typically caused by a mosquito bite. Indicators of the mild form of the virus include fever, head and body aches, rash, lack of appetite and swollen glands. More severe infections can cause high fever, disorientation, stiff neck, muscle tremors and weakness.

An outbreak of West Nile virus has landed in Dallas County, killing 10 from nearly 200 reported cases of human infection.

The mosquito-borne virus has already had a record-breaking year, reporting the most cases since the first United States outbreak since 1999. A C.D.C. report released August 14 said that 693 cases of infection have been reported nationwide. Officials in Texas have reported 17 West Nile-related deaths, and the C.D.C. report said that the disease has killed six in Louisiana. No other state has reported more than one fatality.

The mayor of Dallas has declared a state of emergency and authorized an aerial spraying of pesticide, the first in the city since 1966, as five of the 10 deaths occurred within city limits. Some residents are protesting the spraying, calling it ineffective and harmful to beneficial insects, but Dallas officials insist the procedure is safe, and will assist with slowing the spread of the virus.

Viruses spread by mosquitoes like the West Nile are of special concern to those in the construction and landscaping industry, due to the time spent outdoors. While the C.D.C. report does not separate the incidences of infection by occupation, individuals working outdoors are apt to be more vulnerable to infection. The C.D.C. also said that among those infected with West Nile virus, including people with asymptomatic infections, less than 1% will develop the most severe symptoms.

The pattern of increasing incidence seems to go hand-in-hand with this year's sustained hot weather in California's Central Valley and the heartland. Increasing occurrences have been reported in Cook County, Illinois, which includes Chicago, and more cases are expected while temperatures are high.

West Nile Prevention Tips

• Use insect repellent that includes DEET, picaridin or oil of lemon eucalyptus

• Wear long sleeves, long pants and socks while outside – spray repellent directly onto clothes, not skin

• Be aware of peak mosquito hours (dusk to dawn, early morning and early evening)

• Drain standing water outside the home or at the job site

• Install or repair screens on windows and doors