by Carol Thompson
The Oswego County Health Department was notified by the State Health Department late Tuesday, Sept. 4 that the Eastern equine encephalitis virus was found in a sample of mosquitoes collected last week in the village of Central Square.
Jiancheng Huang, Oswego County public health director, said he has requested the New York State Department of Health to issue a declaration of “imminent threat to public health” in Oswego County with the intent to conduct aerial spraying of the Big Bay and Toad Harbor Swamp area as soon as possible.
“The new evidence of Eastern equine encephalitis, together with the West Nile virus activity already present in Oswego County, drove the decision to spray,” said Huang. “Although the number of mosquitoes collected in trapping sites continues to be much lower than in prior years, considering virus activity in recent weeks, the weather forecast, and as a precautionary measure against a repeat of last year’s unusually rapid emergence of EEE, we need to conduct aerial spraying to control mosquitoes. We have started the process needed to conduct aerial spraying, and we will announce the schedule to the public as soon as it is developed.”
Huang emphasized that the decision on when and where to conduct aerial spraying is based on data collected in surveillance and mosquito control guidelines.
Oswego County Legislator Amy Tresidder, who has been questioning the county’s decision not to spray for the West Nile virus, agreed with Huang’s decision.
“I agree with this decision to spray,” Tresidder said. “I have asked the question for several months as I have been concerned both the West Nile virus and the EEE virus and I feel the health department has made the right decision.”
West Nile and Eastern equine encephalitis are different diseases caused by different viruses and transmitted by different mosquito species, said Huang. The risk of contracting either virus runs from June through September with peak activity late July to mid-August.
The Oswego County Health Department collects samples of mosquitoes throughout the summer to look for evidence of West Nile and Eastern equine encephalitis viruses. EEE is usually detected in bird-biting mosquitoes before it appears in mammal-biting mosquitoes.
In Central Square, the virus was found in the type of mosquito that bites birds — not in a species that feeds on humans. Aerial spraying may help reduce the risk of EEE spreading to human-biting mosquitoes.
Samples of mosquitoes collected earlier this summer in New Haven, Central Square and West Monroe tested positive for West Nile virus.