BRANDON — One man is dead and another remains hospitalized after the first human cases of Eastern Equine Encephalitis virus in Vermont were detected in Brandon and Whiting on Saturday, and state officials are on the offensive.
Richard Hollis Breen, 87, of Brandon died Tuesday from the disease and a man from Sudbury remains hospitalized on Wednesday. Breen lived on the emu farm in Brandon where at least 16 emus died from the disease last September when EEE was for the first time detected in animals in the state.
During his career as an educator, Breen was a principal of Otter Valley Union High School and the head of what is now the Vermont Principals’ Association.
State officials plan to combat the mosquitoes responsible for EEE with aerial spraying of the pesticide Anvil in two areas, one in Brandon and one in Whiting, on Thursday, Sept. 6, from 8-11 p.m.
They announced the plan to more than 180 people who attended the Vermont Department of Health’s public information meeting at the Brandon Town Hall Tuesday night regarding the outbreak. The meeting featured Vermont Health Commissioner Dr. Harry Chen and Agency of Agriculture Deputy Secretary Jolinda LeClair. Also on hand was Agency of Agriculture entomologist Alan Graham, Department of Health epidemiologist Erica Berl and Agency of Agriculture Pesticide Program Section Chief Cary Giguere.
THE DECISION TO SPRAY
The decision to aerially spray the pesticide had to be made quickly, but officials said they did not make the decision lightly.
Chen, who opened his remarks with condolences for Breen family, issued a warning.
“EEE is rare, but it is a terrible disease,” he said. “It is fatal about a third of the time, so this is a fairly disastrous piece of news to have.”
Mosquito pools that have tested positive for West Nile virus annually for the last few years in Whiting, and Brandon recently tested positive for EEE as well. Like West Nile virus, EEE is spread by the bite of an infected mosquito.
People who are infected with EEE can develop two types of illness. One has a sudden onset and is characterized by chills, fever, malaise, and joint and muscle pain, and lasts about one to two weeks. The more severe illness affects the central nervous system and causes fever, headache, irritability, restlessness, drowsiness, convulsions and coma. Approximately one-third of people with severe EEE die from the disease, although right now, Vermont’s mortality rate is 50 percent.
But EEE is so rare that there have only been 300 documented cases in the U.S. over the last 50 years, and only a few cases are reported each year, according to the U.S. Centers for Disease Control.
“One more human case is too many, so we decided to spray,” Giguere said.
The pesticide Anvil contains an active ingredient called Sumithrin, which is a synthetic compound derived from the chrysanthemum plant. It is found in pet flea collars and other household items.
Anvil is commonly used throughout the U.S. in low concentrations to kill mosquitoes.
That said, it is a powerful pesticide and in high concentrations can affect the nervous system. The spray can irritate the eyes, nose, throat and lungs.
Officials at Tuesday’s meeting urged residents — particularly those who are pregnant, have compromised immune systems or asthma — to remain indoors during the spraying and until 30 minutes after spraying is completed.
Also, residents are urged to close windows and doors and turn off air-conditioning units before spraying begins.
And officials suggested that on Friday residents should hose down children’s toys and outdoor furniture exposed to the pesticide before use.
An airplane flying at roughly 300 feet will spray a micro-fine mist of the pesticide over a 10,000-acre parcel in Whiting and an 8,200-acre block in Brandon.
In Brandon, the spray area will cover a rough two-square-mile area from North Street in Forest Dale west across Richmond Road all the way to Steinberg Road in Brandon and north to Ferson Road.
In Whiting, the spray area will run roughly north of Richville Road and west of Cutting Hill Road up Route 30 to Park Hill Road and west of Dewey Road in Salisbury across Swamp Road.
Chen said the state weighed the choice of pesticide and decision to spray very carefully given the risks that come with any chemical.
“It’s not candy,” Chen acknowledged. “Every chemical has effects, and there are steps you can take to protect yourself, but this is a chemical that is routinely used for mosquito control.”
ANIMALS AND VEGETABLES
Residents with backyard vegetable gardens are urged to keep them covered during spraying, but one major concern is the effect the pesticide will have on organic farms. Giguere said he has spoken to officials at the Northeast Organic Farming Association and said a 150-foot buffer will be incorporated into the spray area around those farms.
“We will make sure this is done in a proper manner,” he said. “If it is sprayed over organic farms, that farm will not lose its certification. We will take care of that. We would not want any of you to lose your livelihood.”
Municipal water supplies will also be buffered during spraying.
There is also concern over the effect of the Sumithrin on bees. Giguere said he researched the available pesticides and chose Anvil because “it was one of the least toxic to bees.”
There were also questions from the audience about the effects of the pesticide on household pets, horses and laying hens. Giguere said there would be no adverse affects on pets or horses, and that the eggs from backyard chickens would be safe to eat.
“The half-life of this stuff is only about half a day,” he said. “It won’t make it through the chicken.”
THE BUG TO BLAME
There are 45 different species of mosquito in Vermont, but only one carries the EEE virus. It is the Culiseta melanura and until recently was not often found in the state.
EEE is so rare because this mosquito only lives in acidic hardwood swamps and feeds almost exclusively on birds. The mosquito obtains the EEE virus from the bird and, on the rare occasion it bites a human, transfers the disease that way.
This particular mosquito is also hard to kill. It doesn’t swarm as an adult, which is why aerial spraying is the best way to kill it. Larvicides typically used by the local mosquito control board are ineffective against the Culiseta melanura because it lays its eggs deep within the roots of those acidic swamp hardwoods, making them impossible to get to.
Regardless, it seems it was only a matter of time before EEE manifested itself in the human population here. Last September, 16 emus at a farm on Richmond Road in Brandon were stricken with EEE and died. Vermont’s deer and moose population has tested positive for both West Nile virus for the past several years and for EEE for the first time last year.
There is a vaccine against EEE for horses, but not for humans.
Alan Graham has been testing area mosquito pools for the state for more than 20 years, and he said the Culiseta melanura has only been present in very small numbers until this year.
“We knew it was in the state and it was a perfect storm,” he said. “This year we saw large numbers of Culiseta melanura, particularly in Whiting. We don’t know why.”
There is speculation that a recently built beaver dam near the Whiting test pool, which is on privately owned land, may have altered the habitat in some way, but there is no way to know for sure.
The state’s mosquito testing protocols also changed this year, which may also be why the mosquito pool tested positive for EEE. For the first time, samples were sent to the New York State Department of Health.
“They can do a much more sensitive test,” Berl said. “There has been a change in testing protocol, so it’s hard to say this is the first year EEE has been here. It could actually have been present for several years and we just couldn’t detect it.”
Graham added that while the state was happy to have a better test through New York, there was a downside.
“It was delayed,” he said of the results. “We started sampling in June. We usually got the results weekly. This year, we did not get the results until two weeks ago, and those results were alarming.”
Berl also said there is no rhyme or reason as to why the disease is here now. Mosquitoes like a moist environment and ironically, this summer had been particularly dry and relatively mosquito-free.
“We had a very wet fall last year and a very mild winter,” she said.
Graham and Berl both hailed the efforts of the Brandon Leicester Salisbury Goshen Mosquito Control District for its efforts in getting EEE information out and controlling the overall mosquito population.
“Kudos to your own mosquito district,” Graham said Tuesday. “They have done a fantastic job.”
A MOVING TARGET
State officials acknowledged they are learning as they go, as well as gleaning information from neighboring states with more EEE experience.
“To be honest, we have no history with EEE,” Berl said. “It’s a very tricky disease to predict in terms of what’s going to be a good year and a bad year. I think that it’s a rare enough disease that it’s hard to predict.”
Berl added that even states with a history of positive EEE tests have trouble predicting outcomes from year to year. She said New Hampshire had positive tests starting in 2004 and 2005 and there was a cluster of human EEE cases, then nothing. In Connecticut, Berl said the state had had positive tests in horses for years but has never had a human EEE case. In Maine, there was a grouping of equine cases and no human cases.
“Unfortunately, some of it might be really bad luck as to why one person gets bitten and another doesn’t,” she said.
And while aerial spraying will definitely reduce the number of mosquitoes, including the Culiseta melanura, officials are quick to say it won’t solve the problem.
“We want to hammer home that aerial spraying will reduce the risk, but not eliminate it,” she said. “There is no way to eliminate mosquitoes. It still comes down to personal protection.”
Graham also mentioned that the Culiseta melanura can survive “several hard frosts” and that the risk period will not end until well into the fall.
In the end, the officials thanked residents at Tuesday’s meeting for attending and asking tough questions, and vowed to post as much information as possible on state websites as the situation evolves.
“This is a really challenging topic,” LeClair said. “There is no exact science here. We have a lot of information to post and we will continue to communicate with your mosquito control district, and we hope you will continue to communicate with us.”
For more information and continuous updates on the EEE situation, visit the Vermont Department of Health website, www.healthvermont.gov or www.healthvermont.gov/prevent/arbovirus/eee/eee_public.aspx. You can also visit the Vermont Agency of Agriculture website at www.vermontagriculture.com. For updates from the BLSG Mosquito District and information on additional spraying, go to blsgmosquito.wordpress.com.
These links and other information are also available on the town of Brandon website at www.townofbrandon.com.