PITTSFIELD >> The city has enjoyed a summer season comparatively free of mosquito-related issues, thanks in part to the continued dry weather.
However, Berkshire County Mosquito Control Project Superintendent Christopher Horton said a positive result for West Nile Virus has for the first time this year been recorded in a batch of the bugs trapped in Pittsfield.
The positive hit was recorded from insects trapped in the upper North street/Garland Avenue area, he said, and it will prompt truck-mounted spraying next week.
Upon Horton's recommendation, the Board of Health has approved spraying in that area on Tuesday from 10 p.m. to midnight, with a rain date of Wednesday night. A map of scheduled spray areas is available on the city's website, at www.cityofpittsfield.org/HealthDepartment.
Multiple positive results for West Nile have been recorded in tests conducted at a state Department of Public Health laboratory from mosquitoes trapped at sites in eastern Massachusetts, Horton said, and one human case of the virus was recorded from that area.
The organization, which contracts annually with the city and several other communities in the county to oversee a range of mosquito control efforts, traps and tests batches of mosquitoes at some 250 local sites in the county (150 in Pittsfield) and sends them to the DPH weekly for testing. Prior to the recent test result in mosquitoes, there had been no positive results for West Nile or Eastern Equine Encephalitis here this season.
Concerning the Zika virus, which is widespread in many Central and South American countries and beginning to show up in Southern Florida, Horton said the colder weather of the Northeast has inhibited it. He said most states in the north have weather that acts as a deterrent to the species of mosquito that most commonly carries Zika virus, called Aedes aegyptgi.
However, Horton said the Asian Tiger mosquito, which has been found in New York City and other areas in the region, is a close relative of the virus-carrying species and is being monitored for signs it could spread Zika to northern states.
Although the virus usually produces no more than a mild fever or mild muscle pain in humans, it has been linked to birth defects when the person contracting the virus is pregnant.
In Pittsfield, Horton said the dry weather and lack of river flooding to produce standing water for mosquitoes to breed in has made this season very much "a manageable" one. "It has been so dry that the water sinks right in when it rains," he said, adding, "Everything we have had so far has basically been going into the ground."
In addition, BCMCP crews regularly check areas known for standing water or pools to perform work allowing them to drain, or to treat pools with a larvicide that kills the mosquitoes before they grow to the adult stage.
Horton said the use of two larvicide treatments, one lasting a week in standing water and another lasting a month, has been highly effective since the dual product use was begun last summer.
Hundreds of city stormwater drainage system catch basins also are inspected and treated as needed. And in some instances spraying with backpack-mounted hand sprayers or truck-mounted sprayers are used on large areas or on one or two properties following a complaint of infestation.
Horton said in a recent update to the city Board of Health that truck-mounted spraying was used 11 times, all for one or two properties after complaints of an infestation, and backpack hand spraying of properties occurred eight times.
Spraying of a wider area requires prior approval from the Board of Health, such as the spraying event scheduled for Tuesday. One of the conditions that can trigger such spraying is a positive test for disease in either the trapped mosquito batches or a human case.
Thus far, Horton reported to the city Health Department, there were 102 larvicide treatments of pools or standing water over 202 acres, 5,486 catch basin inspections, with 3,002 larvicide basin treatments thus far; and 151 mosquito pools, or batches of 50, were sent to the DPH lab prior to this week.
Contact Jim Therrien at 413-496-6247.
Protect yourself ...
West Nile Virus is most commonly spread through the bite of an infected mosquito. The best way to protect yourself and your loved ones from mosquito borne illness is to take the following precautions:
• When outdoors, wear long pants, a long-sleeved shirt and socks.
• Use a repellent with DEET according to the instructions on the product label.
• Keep mosquitoes out of your house by repairing holes in screens and making sure screens fit tightly to doors and windows.
• Schedule outdoor events to avoid the hours between dusk and dawn, when mosquitoes are most active.
• Remove areas of standing water around your home to eliminate sources of mosquito breeding.