Equine encephalitis found in local mosquitoes

As of July 20, the State Agricultural Experiment Station collected 109,527 mosquitoes, twice the number for the same period last year. In part, they have been collected in Franklin, Windham and Hebron. All have tested negative for West Nile Virus, Eastern Equine Encephalitis and Jamestown Canyon Virus. Photo by Al Malpa.

Mosquitoes trapped last month in four Connecticut towns – including two locally – have tested positive for the potentially deadly eastern equine encephalitis (EEE), the state Department of Public Health said this week.

Mosquitoes trapped in Hampton and Willington, as well as Madison and Old Lyme, all tested positive for EEE, joining Killingworth as the first towns in the state to produce positive tests this year.

The DPH also announced Tuesday that mosquitoes in Cheshire and Farmington tested positive for West Nile Virus, meaning nine towns (none local), have now produced positive results for the virus.

No Connecticut residents have been identified with infections from either virus this year and the state has never had a confirmed human case of EEE, said Theodore Andreadis, who runs the state’s trapping program.

The Connecticut Agricultural Experiment Station has 91 trapping locations in 72 municipalities throughout the state.

Andreadis said this time of year tends to be the peak time for human cases. “The next couple of weeks are critical, because it’s still plenty warm out there,” Andreadis said.

But he also said the state currently has no plans for spraying or other measures at this point.

Hampton First Selectman Maurice Bisson said he first heard about the positive test in town through the news and had not yet had the chance to talk with state officials.

He also said town officials will not take any action before first talking with the state to determine what is appropriate.

“We’re going to have to wait and see what comes from the state,” Bisson said.

Andreadis said people should make sure they are taking proper precautions when outdoors, including wearing repellents, especially between 7 and 9 p.m.

Symptoms for EEE include a “quite severe” fever, which sets in quickly, nausea and vomiting.

Andreadis said EEE is more severe than West Nile; roughly one out of every three people contracting the disease die.

“It’s potentially quite serious,” he said. Eight out of 24 EEE cases in Massachusetts and New Hampshire resulted in death between 2004 and 2008.

EEE causes swelling in the spinal cord and the brain. Andreadis said people infected with the virus will at least suffer permanent brain damage “with very, very few exceptions.”

He also said people should take extra caution with certain animals, particularly horses and domestic birds, because their fatality rates can approach 100 percent.

People do not need to worry about their cats and dogs, but EEE is a “veterinary concern,” especially among horses, which is why equine (horse) is part of the disease’s name, Andreadis added.

He said the weather has helped limit the spread of West Nile. Mosquitoes carrying it originate in storm drains, catch basins and similar types of water but heavy rains have flushed out many of those areas thus preventing the specific species of mosquitoes from becoming as prevalent this year.

On the other hand, the same heavy rains have been beneficial for the mosquitoes carrying EEE because they originate in marshes and swamps.

In the mid-1990s, the Connecticut shoreline was under siege from EEE scares, with many schools canceling afternoon sporting events.