State plots mosquito strategy
Local officials lobby for early spraying
Prompted by outcry from officials across Southeastern Massachusetts, historically a danger zone for mosquito-borne diseases like Eastern equine encephalitis, the state Department of Public Health will seek the help of specialists from across the nation this month on how best to minimize risk for people.
Among the experts are an entomologist and biologist from the federal Centers for Disease Control and Prevention, a California ecologist and evolutionary biologist, New York state research scientists, an infectious disease physician from Brigham and Women’s Hospital, and a conservation biologist and plant ecologist from Boston University.
Department of Public Health spokeswoman Jennifer Manley said the specialists were chosen specifically because they haven’t been involved in this state’s mosquito surveillance and control processes, and “could be expected to provide fresh perspectives.’’
“Their charge is to help us understand whether or not there has been a change in the observed pattern of Eastern equine encephalitis activity, and to help scientifically evaluate the data and various mosquito control strategies that can be used to reduce the occurrence of human disease,’’ Manley wrote in an e-mail to the Globe.
The specialists are lined up to take part in a conference-call discussion with local health officials later this month.
The latest scrutiny of mosquito trends and control methods is the result of pressure applied by Southeastern Massachusetts officials last fall and winter, following the death of 80-year-old Raynham resident Martin Newfield, who was infected with EEE in late August and died in early September. An elderly Missouri woman also contracted the disease while visiting in the area; the latest update to local health officials said she was recovering in a rehabilitation center last fall.
Raynham officials complained last year that they had been pushing the state without success to do aerial spraying of adult mosquitoes since midsummer. The state never took that step because certain triggers in its protocol for spraying - such as a risk designation rising to “critical’’ - had yet to occur. One such trigger is the death of a horse from the disease.
Because Newfield’s death came late in the season, state health officials said it was too late for aerial spraying to be effective.
Raynham health agent Alan Perry organized his colleagues from across the region, and sent a joint letter to the state health department’s commissioner, John Auerbach, in December, urging aerial spraying of adult mosquitoes this July.
“How can you not do the spraying, having had one person die and another person who was from out of state contract EEE last year?’’ Perry said in a recent interview. “Aerial spraying is a tool. How can we not use it? Public health is about prevention of communicable disease.’’
The letter from the health agents also urged state officials to always consider Southeastern Massachusetts to be at high risk for Eastern equine encephalitis, based on the region’s history. Last summer, mosquitoes carrying the EEE virus were found in 20 area communities.
Eastern equine encephalitis, first detected in the United States in 1938, attacks the brain and nervous system. The mortality rate is 30 to 50 percent, and many survivors suffer lifelong neurological disability. There is no treatment for the illness.
For the past several years, the majority of the state’s EEE cases have occurred in Norfolk, Bristol, and Plymouth counties. The state also keeps an eye on the West Nile virus, another mosquito-borne infection, which produces flu-like symptoms from which most victims recover.
Auerbach will seek input from Perry’s group of health agents, allowing three representatives to present their concerns and propose solutions to his panel of experts during the upcoming conference call.
Meanwhile, some area residents are already reacting with some alarm to the early presence of mosquitoes, and calls have been pouring in to regional mosquito control agencies. But there’s no reason to worry yet, officials said.
“The mosquitoes that are out now overwintered as adults,’’ said the Bristol County Mosquito Control Project’s acting superintendent, Stephen Burns. “This type doesn’t carry EEE. Most likely it will become cold again and those mosquitoes will be gone.’’
In any case, the typical mosquito only lives about two weeks, he said, leaving the public with several worry-free weeks ahead. “The new batch starts to hatch in mid-May,’’ Burns said.
The mosquito forecast for this summer remains uncertain. “It depends on how much moisture we get this spring,’’ said Mansfield’s health agent, Scott Leite.
Duxbury health agent Tracy Mayo said she isn’t sure what this summer would bring, but noted that residents are concerned about mosquito-related health threats. “We are always conservative about restricting outdoor activities,’’ she said, citing the detection of mosquitoes carrying the virus in Kingston, “right next to us.’’
Manley said the mild winter favors a large population, but the current extended dry spell, if it continues, would keep the bug population down.
“The bottom line is that the ecology of our different mosquito species is complex and variable by species,’’ she said. “It is not possible to accurately predict what our summer season will be like.’’
Leite said the region’s health agents are pushing the state for better notification about infected mosquitoes this summer. In the past, a community with a pool of infected mosquitoes would be notified by the state, while its neighbors were not.
“The message should be consistent through the whole region, telling us of an infected pool and its location,’’ Leite said. “If there’s an infected pool in Easton, that’s right next to Mansfield, and mosquitoes fly past boundary lines.’’
Christine Legere can be reached at firstname.lastname@example.org.