Apr. 21--There will likely be a bumper crop of mosquitoes this summer, following the unusually wet March, but that doesn't necessarily mean more cases of West Nile virus, health officials said Tuesday.
In fact, the number of human infections nationwide has been dropping steadily since 2003. Last summer was the first in nine years that there were no human cases of West Nile virus in the state, said Theodore Andreadis of the Connecticut Agricultural Experiment Station.
Dr. A. Dennis McBride, Milford's health director, said the wet spring is already having an effect.
"We are seeing larval activity much earlier this year than in 2009, because the record amounts of rainfall in March created ideal conditions for breeding."
The culex pipiens mosquito that is a vector for West Nile virus is most common in lower Fairfield and New Haven counties, along the Interstate 95 corridor, Andreadis said.
But wet springs don't translate into bad summers for the virus, the state research scientist said.
"When we have hot, dry summers is when we see the most cases, because that species of mosquito is more urban," the researcher said. "It will find residues of moisture in catch basins and storm drains."
That's why it's important to treat any area with standing water, and eliminate sources such as pool covers, bird baths and old tires, Sands Cleary, Fairfield's health director, said.
"We've treated stagnant water areas with BTI (a larvicide), and we'll provide BTI for residents to treat their properties," Cleary said.
But, if necessary, town officials will take enforcement action against property owners who do not remove insect-breeding elements, he said.
Milford launched its $62,000 annual mosquito control program a few weeks ago, Mayor James L. Richetelli Jr. said. The contractor, All Habitat LLC, has been applying larvicide in marshes and later will use BTI "doughnuts" in catch basins, he said.
"It's all about staying out ahead of it," the Milford mayor said.
Of the 46 species of mosquitoes in Connecticut, only 12 are considered pests, or vectors of disease in humans. One species, more common in the eastern end of the state, is responsible for Eastern equine encephalitis, a serious disease that is on the upswing.
"It is moving north -- last year there were cases for the first time in Maine and Nova Scotia," Andreadis said. "There is speculation in the scientific community that it may be due to global warming, but that's conjecture at this point."
What is known is that the mosquito-borne EEE has caused nine deaths, out of 26 cases, in the Northeast since 2004, according to the U.S. Centers for Disease Control and Prevention.
"EEE is of very great concern to us, because it was very abundant in the mosquito population last year, and it can winter over," Andreadis said.
A third species is the one that most residents contend with every summer -- the biting marsh mosquito. "They are not linked to disease but they are very aggressive," said Cleary, the Fairfield health director. "They've been known to bite in broad daylight."
His town is taking steps to control the pests, working with the state Department of Environmental Protection on a project to clean the trenches in the South Pine Creek Marsh.
"We want to clean it of yard debris and other material so the fish can get in and eat the larvae," Cleary said.
-----
To see more of the Connecticut Post, or to subscribe to the newspaper, go to http://www.connpost.com/.
Copyright (c) 2010, Connecticut Post, Bridgeport
Distributed by McClatchy-Tribune Information Services.
For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.