In an effort to reduce the chance of a second, more severe outbreak of Eastern Equine Encephalitis this summer, the Connecticut River Area Health District — serving Clinton, Old Saybrook, Deep River, Haddam and Chester — will hire a private contractor to treat all the storm drains in their region with larvicide.
“Beyond our customary outreach campaigns, we are going to expand our efforts. CRAHD will be hiring a private contractor to treat with larvicide all catch basins … I am hopeful that these measures will be used in neighboring communities,” said health district Director Scott Martinson. “The bottom line is reducing the number of adult mosquitoes through the use of larvicide which in turn reduces the risk of disease transmission.”
So far, neighboring health districts – Essex and Ledge Light – have yet to announce plans for larvicide or insecticide treatments this year.
CRAHD’s increased prevention efforts come after the worst outbreak of Triple E in Connecticut’s history with four individuals contracting the virus last year. By comparison, between 2008 and 2018 there was just one case in the state.
“One thing to consider is this is all driven by the immunity of the host song birds and the level of the mosquito population,” said Lesley Dupoy, a health scientist administrator and program officer in the virology branch of the National Institute of Allergy and Infectious Diseases. “Because of this past summer, we expect the next two to three years to see an increase in cases if the weather is warm and wet.”
It is not only increased rain and heat, but increased wetlands in southeastern Connecticut that may be contributing to the rise in EEE infections. The mosquitoes that spread EEE develop in underground water-filled basins at the base of swamp trees, according to Phil Armstrong, a virologist and medical entomologist at the Connecticut Agricultural Experiment Station.
When Connecticut was mostly farmland, there were many fewer of these swamp trees where these mosquitoes breed.
“I have seen a dramatic increase in red maple swamps that have been converted to beaver ponds in the last 20 years,” said Emery Gluck, a state forester for the Connecticut Department of Energy and Environmental Protection. “Just from observations, wetlands seem to be at least a little more extensive as there are numerous old forest roads that are now primarily underwater at least part of the year. This might be at least partially attributed to beavers.”
Despite the high likelihood that the virus will return and even grow in prevalence this year, the shortened legislative session has so far prevented any additional allocation of funds on the state level to address the problem. The Connecticut Agricultural Experiment Station had requested $150,000 to establish 15 additional testing sites.
“The Department of Public Health submitted testimony in support of this budget proposal I believe,” said Av Harris, Director of Communications and Government Relations for the Department of Public Health. “The legislative session is discontinued due to the pandemic, so no legislation will be passed during the regular session. But, there remains the possibility legislators could convene a special session to address budgetary matters. We remain hopeful that this funding will be addressed at some point.”
For now, however, the experiment station will not be establishing new sites and the Department of Energy and Environmental Protection has no plans for any additional larvicide or insecticide treatments.
“At this point the DEEP does not have the funding nor the intention of distributing larvicides to municipalities,” said Roger Wolfe, the Wetland Restoration and Mosquito Management Coordinator for the Connecticut Department of Energy and Environmental Protection. “We can provide technical assistance on identifying sources of mosquito production around the home and neighborhood, means of reducing or eliminating those sources and information about repellents and other insecticides for municipal and homeowner use.”
In the absence of a state-level response, towns and health districts in southeastern Connecticut are considering taking action on their own.
“We are discussing it at the COG level,” said East Lyme First Selectman Mark Nickerson, whose town saw the majority of human cases in 2019. “But it’s too early to say if we will make investments in testing or prevention this year. We are waiting for direction from DPH and our health district.”
In an April 21 meeting, East Lyme cut their budget for mosquito spraying by $5,548.
According to the minutes, Nickerson said, “we just do not have a handle yet on what we might need to do this year for spraying and we will ask Mr. Mansfield of Ledge Light Health District to attend upcoming meetings to discuss this further.”
Ledge Light Health District, which covers 10 cities and towns east of the Connecticut River, was forced to cope with an significant outbreak of the virus in 2019. Ledge Light was unavailable for comment on this story.
Apart from larvicide and insecticide treatment, EEE prevention may look similar to current orders to prevent COVID-19, including closing state parks to overnight camping and rescheduling or canceling outdoor activities during times of peak risk, Armstrong said.