Aerial spraying over portions of Manorville and Calverton begins Wednesday at 7 p.m. in the heightened battle against breeding adult mosquitoes that may harbor the potentially deadly Eastern equine encephalitis virus.
A helicopter will spray until midnight Thursday in response to the State Health Commissioner’s declaration of an “imminent threat to public health” on Friday. The Suffolk County Department of Health Services sought the declaration last week after confirming a mosquito sample had tested positive for the triple-E virus.
The pathogen causes a rare but potentially fatal brain inflammatory illness in humans and horses. The disease is of special concern for horse owners because of an exceptionally high mortality rate in the animals. A veterinary vaccine is available.
Vector control officials are targeting the mosquito species, Culiseta melanura, which was found to be positive for triple E in an August 16 sample. Only females of the species actually bite for blood, which they use for egg maturation. They mostly feed on birds. Males feed on nectar.
“The reason triple E is less common in humans is that the primary mosquito vector, Culiseta melanura, does not typically feed on humans,” Dr. James Tomarken said in a statement on Friday. “However, the virus may be transmitted to humans and horses by bridge vectors, which are other kinds of mosquitoes that have contracted the virus by feeding on infected birds.”
Officials say there is no evidence of triple E being carried by mosquitoes that do actively feed on people. Aerial spraying will be conducted in an ecologically sensitive region. The declaration issued by the State Health Commissioner on Friday allows spraying in a protected wetland area.
In an email Monday evening, Suffolk County health authorities identified the areas to be sprayed as streets extending from River Road/Grumman Boulevard to South River Road and the Long Island Rail Road tracks, extending from Princeton Avenue to Railroad Avenue.
They identified the insecticide as sumithrin, commercially known as Anvil, the same one used in the fight against mosquito-borne West Nile virus. Officials referred to the type of spraying as ultra-low volume aerosol.
Children and pregnant women should avoid exposure.
If possible, remain inside or avoid the area whenever spraying takes place and for about 30 minutes after spraying. Close windows and doors and close the vents of window air-conditioning units to circulate indoor air or, before spraying begins, turn them off.
The spray does not leave significant residues, officials said Monday, but exposure can be further reduced by taking the following steps. Pick homegrown fruits and vegetables expected to be soon eaten before spraying occurs.
Also, bring laundry and small toys inside, and wash with detergent and water if exposed during spraying. Pet food and water dishes also should be brought inside, and ornamental fishponds covered.