Q: What's the outlook for West Nile virus this season?
A: As of May 6, human cases of West Nile infection had been reported in Arizona, Tennessee and Mississippi. Expect numbers to spread as mosquito activity peaks during warmer months.
Birds carry West Nile, which is transmitted to mosquitoes that bite them. In turn, the bite of infected mosquitoes passes the virus to humans and horses or other animals.
The virus does not appear to be transmitted from person-to-person by touching, kissing or other casual contact. However, in a small number of cases, it has spread through blood transfusions, organ transplants, breast-feeding and from mother to child during pregnancy.
Most people who get infected don't get sick. About 20 percent develop the mild, flu-like symptoms of West Nile fever, including fever, headache and body aches. These symptoms generally appear from three to 14 days after the bite, last a few days, then go away on their own.
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More rarely, an infected person develops the severe West Nile encephalitis or meningitis, which can cause permanent neurologic damage or death. Signs include headache, high fever, stiff neck, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. Report such symptoms right away.
Those most at risk are older adults and individuals with weakened immunity.
Your best defense is to shun contact with mosquitoes.
Insect repellents help keep mosquitoes away. The most commonly used mosquito repellent is DEET. Others include picaridin and plant-based oil of lemon eucalyptus. Neither of the latter prevents bites for as long as high-concentration DEET.
A higher concentration of DEET doesn't mean your protection is better, only that it lasts longer.
For instance, a 10 percent product lasts about two hours, a 24 percent product about five hours. Choose based on the time you expect to spend outdoors.
DEET-based repellents may be used along with a separate sunscreen. It's unclear whether other repellents can be used this way.
Apply the repellent sparingly to exposed skin but not to skin under clothing.
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DEET appears to be acceptable for use in kids over 2 months old. Don't use on their hands, because it could get into the eyes or mouth.
Avoid applying repellent to broken or irritated skin. After your outing, wash treated skin with soap and water.
An additional way to protect yourself is to wear a long-sleeve shirt, long pants and socks. You also can use a DEET or permethrin-based product on clothing.
Keep in mind that mosquitoes are most active around dusk and dawn.
They lay their eggs in standing water such as ponds, roadside ditches, and containers. To prevent breeding, empty any sources of standing water around your house.
You can help track West Nile virus activity by reporting any dead birds you find to the local health department.
Richard Harkness is a consultant pharmacist, natural medicines specialist and author of eight published books. Write him at 1224 King Henry Drive, Ocean Springs, MS 39564 or rharkn@aol.com .
