|
|
8.17.2000 00:15
DEM to check
effectiveness
of spray today
 Traps will be inspected to determine how many mosquitoes were killed by the insecticide sprayed Tuesday to combat West Nile virus.
By MICHAEL SMITH
Journal Staff Writer
WARWICK
-- Early this morning, scientists are expected to find out whether the insecticide sprayed in Cranston and Warwick on Tuesday to kill mosquitoes that may carry West Nile virus did its job.
The Department of Environmental Management will check three mosquito traps set out yesterday evening in the sections of the two cities where the insecticide Sumithrin was sprayed. They'll compare the number of mosquitoes caught in the traps with the number trapped in previous weeks.
The insecticide should have killed most of the mosquitoes in the area.
City and state officials opted to spray Tuesday night because of a dead American crow found at 292 Pine St., in Warwick, that was carrying the West Nile virus, which it likely contracted from a mosquito bite. In rare instances, West Nile can be fatal to humans. It was the first time the virus has been found in Rhode Island.
Yesterday, Massachusetts state officials said mosquitoes carrying the West Nile virus were found in a Brookline neighborhood, according to the Boston Globe. On Monday, six infected crows were found in the Jamaica Plain-Brookline area, so far the state's only "hot spot."
Last year, when scientists first detected the virus in the United States, seven people died from encephalitis, an inflammation of the brain caused by West Nile. All of the deaths were in the New York metropolitan area.
This year there have been three confirmed cases, all in New York and none of them fatal.
Most people who contract the virus feel flu-like effects and do recover. The DEM says residents should avoid mosquito bites by staying indoors at night when possible and not allowing water to stagnate. Sitting water is often a breeding ground for mosquitoes.
Besides this morning's check to see how many mosquitoes were killed by the insecticide, the DEM will also send mosquitoes trapped on Tuesday evening to a lab at the University of Rhode Island to determine whether they were carrying the virus, said Alan Gettman, mosquito abatement coordinator for the DEM. Obtaining results from the tests usually take about a week.
The DEM traps mosquitoes every week around the state during the summer, then sends the insects to be tested. In a typical week, about 30 traps are set. The latest tests, on insects caught Aug. 7, were negative for West Nile virus.
The woman who found the dead crow in her back yard last Tuesday, Marion Cragan, 83, said there were no unusual markings on its body. Her granddaughter later called the DEM.
"Only because of all the stuff on television," she said. "We didn't touch it, of course."
Test results on the dead crow came back on Sunday, showing it was carrying West Nile. Cragan said she wanted to keep her find quiet, and didn't even tell her neighbors. But she was glad to see the spraying crew in front of her house Tuesday, and watched them from her window.
The DEM doesn't test every dead bird residents report. Only those with no obvious cause of death or ones that are still alive but staggering tend to raise red flags, said Stephanie Powell, spokeswoman for the department.
Tuesday night, four trucks sprayed a total of 102 street miles in Cranston and Warwick, about 70 percent of which was in Warwick. A two-mile radius around the house on Pine Street was sprayed. Crews began the work at 7 p.m. and finished at about 2 a.m.
Yesterday's early morning rainfall shouldn't have limited the spray's effect to any great degree, DEM officials said. The insecticide attacks the nervous system of mosquitoes, killing them quickly.
It loses half of its potency after nine hours in the air or water. When in the soil, it can last a few days, said Elizabeth Lopes-Duguay, senior environmental scientist for the DEM.
The insecticide, while it is still potent, can be lethal to aquatic life. But it tends to stick to the soil, said Lopes-Duguay, reducing the risk of runoff into nearby bodies of water. Crews avoided spraying streets that were next to water because of concerns about harming fish.
Health officials say Sumithrin is a mild insecticide, but can cause complications in people who have allergy problems. No one reported any serious complications from the spraying, though some called the state Health Department to say they had headaches, said Mary Jo Takach, department spokesperson.
Takach also made checks with local walk-in clinics to see if anyone complained of health effects. None was reported, she said.
Some people complained that they were outside when the trucks passed through their neighborhoods and breathed in the chemical because they weren't given enough warning of the spraying. Spray trucks were preceded by either public works trucks with flashing lights or police cars.
Ken Burke, director of public works for Cranston, said causing too much racket in the neighborhood could have been worse.
"I didn't want to alarm people or put them in a situation where, as we were driving through, we would draw people outside," Burke said.
West Nile virus most often appears in American crows. Of the 188 birds found infected as of Aug. 7, 78 percent were crows, and 12 percent were blue jays, which are related to crows.
There are two reasons why scientists think that may be the case, said Gettman of the DEM. The immune system of crows may not be equipped to handle the virus.
The other reason is that crows are attracted to urban areas and simply may be discovered dead more than other birds, he said.
|
|
|
Printer-Friendly Version
