W. Nile virus pops up earlier this year

By Victor Zapana
Special to the Register
NEW HAVEN — It might seem early for some residents to whip out the mosquito repellent. Then again, it might not.
Mosquitoes infected with the West Nile virus were found in eastern Connecticut, Pennsylvania and New York earlier this month. The discoveries mark the earliest in the year the disease has appeared in the region.
"We may have been lucky — or unlucky, depending on your perspective — to detect the virus … so early," said Theodore Andreadis, director of the state-funded Mosquito Virus Surveillance Program.
Although scientists said they do not know yet whether the early presence will mean an earlier or extended West Nile virus peak season, they warn that people should protect themselves from the pests.
They added they are increasing efforts to monitor the virus earlier than usual to gather more data.
State health experts said they cannot point to a specific cause for why West Nile popped up early.
Some point to a trend that the disease has gradually emerged earlier in the season each year. Others cite the four-day heat wave that hit the region early last week as a potential cause for the virus’ early arrival.
Official mosquito virus testing in Connecticut started June 2, according to the state Department of Environmental Protection. Since then, state scientists found one case of West Nile in a Culex pipiens mosquito June 11 in Stonington, the first case in the Northeast this year. The Culex mosquito is a confirmed West Nile carrier, experts said, and the insect prefers marshy coastal areas.
In the Northeast, peak mosquito season is July to August, experts said. Generally, West Nile-positive mosquitoes are discovered in late July, and peak season lasts from August to September, said Andreadis, who also is chief medical entomologist at the Connecticut Agricultural Experiment Station in New Haven.
West Nile is often found in birds, but it can be transmitted to humans through the bite of an infected mosquito. The disease is not contagious, and most humans show no symptoms or have only mild headache and fever. But in some cases, West Nile can cause severe encephalitis, or brain inflammation, which can lead to disorientation, paralysis, coma or death. About 10 percent of all symptomatic cases result in death, experts said.
So far this season, there have been no reported human cases of West Nile in the state, experts said.
State Department of Public Health Commissioner J. Robert Galvin suggested in a statement that residents remove sources of standing water to eliminate mosquito breeding grounds. Other experts said using repellents containing DEET or Picaridin helps to ward off the insects.
On Sunday, the start of National Mosquito Control Awareness Week, a state mosquito management Web site will go online. Residents can find testing results and information on control at www.ct.gov/mosquito.
Victor Zapana is a New Haven Register intern.