West Nile Virus Concerns—

Town Health Officials Renew Attack On Mosquitoes

By Steve Bigham

For the second time in less than two months, town workers will drop briquettes containing bacterial larvicide into local catch basins in an effort to cut down on the mosquito population. This preventative measure against the West Nile Virus should provide the town with enough coverage until the first frost.

Health District Director Mark Cooper announced the town’s plans on Tuesday, saying mosquito breeding was still being detected. Highway crews were expected to begin dropping the donut-shaped larvicide late this week. Meanwhile, health officials are urging residents to continue efforts to reduce standing water and to use bug repellants whenever possible.

To date, nearly 15 dead crows have been found in Newtown (six in the past week), but unlike in other area towns, none of those found locally have yet tested positive for the virus. In Danbury, a horse had to be put down after being diagnosed with the West Nile virus, one of three cases of infection in mammals in the state this year. No human cases of the mosquito-borne disease have been reported in Connecticut this summer, but infections have been reported in New York. The type of mosquito that bit the horses also bites humans, state officials said.

As Mr Cooper points out, the virus is “all around us,” and that has residents feeling somewhat concerned. “I am concerned for myself and my wife as well as I am for my horse or vice versa,” noted Newtown horse rider David McCauley. “Bethel is very close. I don’t know what to do. I don’t know if there’s a cure or a vaccine.”

One thing is for sure, Mr McCauley added, he is keeping the phone number of his local veterinarian close by just in case something happens.

Veterinarian Ned Schankman of the Connecticut Equine Practice said there is no vaccine to protect horses against the virus, unlike Eastern Equine Encephalitis, which does have a vaccine.

“It’s very obviously very upsetting when horses get attacked by something like this and have to be put to sleep, but there’s not very much we can do about it. We’ve never had it in Connecticut. All we can do is try to decrease the mosquito populations. We need cold weather. We need a frost,” Dr Schankman said.

Of course, it will likely be another month before the temperature drops that low.

Dr Schankman said horses should not be destroyed unless they have such severe clinical disease that there is no hope for recovery.

Last year, 25 horses on Long Island tested positive for the West Nile Virus. Nine of them died. There are some horses that make complete recoveries, although there is no treatment for them.

The DEP on Friday recommended insecticide spraying in a two-mile radius around the sites where the horses were located, including Bethel.

“Having three horses sick with WNV in three different parts of the state, all within a week of each other, is a cause for concern,” said DEP Commissioner Arthur J. Rocque, Jr.

Also Friday, Theodore Andreadis, who heads the mosquito testing program at the Connecticut Agricultural Experiment Station, said the Centers for Disease Control and Prevention may begin testing Connecticut residents to determine the prevalence of the disease in humans.

Scientists say the risk of infection from West Nile virus is low. Since most people exposed to the virus show no symptoms, it is hard to track where and how often the virus is transmitted. Children, the elderly, and people with weakened immune systems are most at risk.

West Nile virus can cause a range of flu-like symptoms. In the most serious cases, infection can result in encephalitis, or swelling of the brain.

“West Nile virus is back with a vengeance this year. It is much more widespread than any of us expected it would be,’’ Mr Andreadis said.

The West Nile Virus is a mosquito-borne viral infection that can cause inflammation of the brain. It is named after the West Nile district of Uganda where the virus was first isolated in 1937. The elderly are most susceptible to this virus. West Nile is spread to humans by the bite of infected mosquitoes. A mosquito is infected by biting a bird that carries the virus.

“If it begins to move in this year, we will have been ahead of the game and there will be less mosquitoes to act as the vector to humans,” Mr Cooper said.

Unlike the sprays used in other towns, the donut-shaped larvicide are non-chemical. According to Mr Cooper, the donuts are made up of a natural bacteria, which, when dissolved, are eaten by mosquito larvae. In time, the bacteria succeed in breaking down the larvae’s intestinal wall, killing it.

Half of the town’s 4,000 catch basins – prime spots for mosquito breeding – will get a larvicide briquette.

The larvicides were provided to the town under a $9,000 grant from the state’s Department of Environmental Protection (DEP).

(Associated Press reporting was used in this story.)