Samples result in spraying for virus - Boston.com

Mosquito spraying was scheduled in Winthrop, Revere, Saugus, and Tewksbury this week in response to positive findings for West Nile virus in mosquito samples taken in those communities last week.

Test results received from the Department of Public Health this past Thursday and Friday yielded a total of 17 positive findings in pools of culex pipiens and colex restuans mosquito types, vectors of the virus.

The findings came from samples taken in seven North Region communities. In Malden there were six positive findings, from three traps. There were three positive findings in both Melrose and Medford, two in Revere, and single-sample positives in Saugus, Winthrop, and Tewksbury.

In Revere, the findings came from a trap that had also produced positive findings in the previous two weeks, near Beach and Harris streets. The area had already been sprayed, but the city asked for another round of localized spraying by the Northeast Massachusetts Mosquito Control and Wetlands Management District,  which manages the mosquito population in 33 Essex County communities, plus Revere and Winthrop.

The district conducted a targeted spraying in Saugus on Monday, and director Jack Card  had scheduled a town-wide spraying in Winthrop last night. The Central Massachusetts Mosquito Control Project, which manages mosquitoes in 40 communities in Worcester and Middlesex counties, also planned a targeted spraying for Tewksbury on Tuesday night. 

“Hopefully, nothing else will come our way on Friday,” Card said, referring to the day the Mass. Department of Public Health provides results to the district after the mosquito samples have been tested.

The management companies have also treated catch basins and other breeding grounds, and local public health officials issued warnings to residents to take precautions such as using mosquito repellent with DEET, wearing long sleeves and pants when possible, being wary of mosquitoes during the peak activity periods of dusk and dawn, and eliminating standing water in artificial containers such as gutters, bird baths, and spare tires, where the culex species breeds.

“Even in my backyard, it’s brutal in the early morning,” said Nicholas Catinazzo, Revere's public health and municipal inspections director. “There’s not much we can do other than spray and make sure people are mindful of it.”

Thus far this year, there have been no human or animal cases of either West Nile virus or Eastern equine encephalitis in the state. Transmitted by mosquitoes, both diseases are potentially fatal to humans.

There have been no EEE findings in the North Region this year, despite an abundance of mosquito findings in Bristol County and elsewhere, including the first finding on Cape Cod, in Brewster. There was an EEE finding last week in Sudbury, a Middlesex County community where it was also found in 2011. For that reason, mosquito control experts were spraying in Sudbury and Marlborough on Monday.

Mosquito control professionals have said that the season is running two weeks ahead of the norm, as a result of the hot, dry summer. All of the communities have had some history with West Nile virus, and David Henley, superintendent for the East Middlesex Mosquito Control Project, said that given the high population density and urban setting, it isn’t unusual to see the positive findings in the urban communities clustered around Boston.

“In the East Middlesex District since 2001, we’ve had 22 [human] cases of West Nile virus and 21 of those have happened in cities and towns with populations of 3,000 people per square mile,” Henley said. “If you look, there’s an area around Boston where all the cities and towns have that population density. So what you have is one enormous area that is a really productive culex area, regardless of town border. All of our West Nile human cases have happened inside of Route 128. There are more wetlands outside of Route 128 that produce a lot of mosquitoes, but culex mosquitoes aren’t coming from wetlands. They’re coming from water-holding containers.”

Reach David Rattigan at DRattigan.Globe@gmail.com.

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