Health Officials Fear Rise in West Nile Cases After Wet Spring

After what seemed an eternally long, soggy spring, the warm, dry weather has lured hordes out of hiding.

That's true of people - and mosquitoes, too.

The insects have been busy breeding in pools of water formed by the abundant rain of the last several months. But it's only in the last week or so that they've been able to get out for a bite - now that their wings are dry enough to stay airborne.

Now, as New York health officials begin to report sudden spikes in their mosquito counts, some say the conditions are ripe for an especially buggy summer, which could potentially lead to higher numbers of West Nile virus cases.

``Right now, all the conditions seem to be in place to have a really sizable mosquito population, certainly within the next month or so,'' said Bryon Backenson, assistant director of the state Health Department's arthropod-borne disease program.

Mosquitoes typically pick up West Nile virus when they bite an infected bird, such as a crow. They then spread it to other birds, animals and people.

People exposed to the virus have a range of reactions. Many develop mild flu-like symptoms and never know they had the disease. In the worst cases, the virus can cause brain swelling or meningitis. Generally, people older than 50 and with weakened immune systems are at highest risk.

Last year, West Nile virus struck with its deadliest force since appearing in this country in 1999 - killing 284 people. More than 4,000 cases were reported in 44 states, according to the Centers for Disease Control and Prevention in Atlanta.

In New York, where the first American cases of the virus were identified, the disease infected 82 people in 2002, killing at least five. A 95-year-old Schenectady man was among those determined to have the disease when he died, though the cause of death was never pinpointed.

The illness seems to be off to a slow start this year - but that may be because the mosquitoes haven't had a chance to spread it around, said Stephen Lukowski, Albany County's director of environmental health services.

Just two dead crows have tested positive for West Nile virus in the state this year. One was in Westchester County, the other in Genesee.

But within the last week, health officials around New York have reported larger numbers of mosquitoes in their counties, Backenson said. Scientists set traps to track the numbers and species of mosquitoes in an area, then test some of the bugs to see whether they're carrying the virus.

The mosquito species most associated with West Nile - culex pipiens and culex restuans - generally do not hatch until July and August. Still, large numbers of all mosquito types may make it easier for the virus to spread later in the summer, Backenson said.

Early in the transmission cycle of the disease, culex pipiens and culex restuans help to circulate the illness from bird to bird - their favorite source of blood. As the disease becomes more common in the environment, other mosquitoes pick it up and spread it - to other birds, mosquitoes, mice, horses and people, Backenson said.

The bottom line: Swarms of mosquitoes - no matter what type - are bad.

Experts suggest wearing insect repellent and avoiding the outdoors at dawn and dusk, when mosquitoes are most likely to be at peak numbers.

It's also important to empty bird baths, gutters, the tops of unopened swimming pools, kids' toys - and anything else that holds water to keep mosquitoes from multiplying, health officials said.

``It's really important for people to look around in their own back yards to make sure that they remove standing water,'' Lukowski said. ``Because that's really the prime source - the small little pools of water.''

Source: New York Times. Tuesday, July 1, 2003