State sees first death from EEE; mosquito-targeted spraying under way

Mosquito

Photo by Arthur Chapman.

The Eastern equine encephalitis (EEE) virus killed a Vermont man earlier this week in what the state Department of Health confirmed is the first human death ever in the state from the mosquito-borne illness.

The virus took the life of Richard Hollis Breen, 87, of Brandon, a former Otter Valley Union High School principal, on Tuesday. The Addison County Independent reported that the virus also hospitalized a Salisbury man.

These are the first two documented cases of humans contracting EEE in Vermont.

Earlier this year, state officials first discovered traces of EEE in mosquitos in the Addison and Rutland County towns of Whiting and Brandon. To address the issue, the Agency of Agriculture and the Department of Health (DOH) called for the aerial application of pesticides last night.

For the first time ever, the Agency of Agriculture took to the skies just after 8 p.m., aiming to spray large swathes of mosquito habitat in Whiting and Brandon with the pesticide known as Anvil. Due to lightning and poor visibility, however, the pesticide crew had to halt its activity.

A joint press release from the two state agencies indicates that the spraying will pick up again tonight at 7:30 p.m. and likely continue until 11 p.m. If the weather cooperates, the Brandon area will be sprayed in its entirety, as well as a portion of Whiting that was missed last night.

The DOH is instructing residents in those areas to stay inside until about 11:30 p.m. Residents should close windows and doors on their homes and kids’ toys and pet food should be brought inside. The DOH also advises that livestock not graze on sprayed pastures this evening and that homeowners with small organic gardens might consider covering them.

The pesticide Anvil

The chief ingredient in the pesticide Anvil is a synthetic chemical called sumithrin. It is classified as a pyrethroid insecticide, which according to the U.S. Environmental Protection Agency is adapted from chrysanthemum-derived insecticides categorized as pyrethrins.

CDC spokeswoman Candice Hoffmann said the application of Anvil is a common method to control outbreaks of EEE-infected mosquitos. The chemical specifically targets the adult mosquito population. Thus far, she said, Vermont officials have followed federal protocol to a tee.

But Anvil is neither benign, nor guaranteed to work.

A Vermont DOH fact sheet on the pesticide explains that exposure to this type of chemical can cause vomiting, central nervous system failure and tremors, among other complications.

When Vermont Deputy Commissioner of Agriculture Jolinda LaClair was asked about the effectiveness of Anvil, she spoke frankly.

“There’s a 10 to 90 percent rate of efficacy,” she said.

To assess the effects of the spraying, the state will need to heavily survey the mosquito populations of those areas. Funds for such surveillance, however, are shriveling up.

Erica Berl, Vermont infectious disease epidemiologist, said that the state mosquito surveillance program is working with nearly a quarter of the federal funds it had a year ago.

“We received $190,000 last year, and we got $50,000 this year,” she said about cuts to the federal “arbovirus” surveillance program, which is administered by the CDC. Arbovirus stands for arthropod-borne virus.

Tasked with capturing mosquito samples and meticulously analyzing them on a shoestring budget is state entomologist Alan Graham of the Agency of Agriculture. Over a 15-year period, he has sampled more than 1 million mosquitos in Vermont for EEE and the mosquito-borne West Nile virus.

But it wasn’t until this year that he came across EEE in Vermont mosquitos.

In 2010, the DOH and the Agency of Agriculture teamed up to test deer blood samples from across the state for EEE. When the results came in, Berl said she was surprised to find that 10 percent of the ruminants were carrying the virus.

That was the first time EEE’s presence was detected in the state.

That autumn, roughly 500 hunters brought their trophies to state officials, who then blood samples. The deer, however, posed no risk of spreading the virus. In mammals, the virus doesn’t build to levels high enough to infect others, said Berl.

“Mammals are pretty much dead-end hosts. The virus either kills them or it gets fought off,” she said.

The first case of EEE in Vermont domesticated animals was detected last September on an emu farm in Brandon. More than a dozen emus died as a result of the virus. That farm was the home of Richard Breen, the man who died from the virus earlier this week.

What is EEE and how does it spread?

The EEE virus has an incubation period of four to 10 days and can result in two types of illnesses.

The first illness is a systemic infection spread throughout the body. It’s characterized by cold-like symptoms such as chills, fever, stiffness of the joints and muscle pain. The second form is full-on encephalitis and can result in coma, convulsions, vomiting and, in severe cases, death.

According to the Centers for Disease Control and Prevention (CDC), there is no known treatment for EEE.

On average, the CDC reports that there are six documented cases of EEE in the United States each year. Before this week, there were only three this year: one in Massachusetts, one in Virginia and another in Florida. Massachusetts health officials reported today that a man died of EEE in August, and another resident was just diagnosed with the virus.

The disease tends to concentrate around wet mosquito breeding areas, like the Atlantic Ocean, the Gulf of Mexico, the Great Lakes and the St. Lawrence Seaway.

Graham found seven instances of EEE in mosquito samples taken by swamps in Whiting and Brandon. In one of the Whiting samples, Graham also found the West Nile virus, which was discovered in a hospitalized Franklin County patient earlier this week.

EEE mainly spreads between Culiseta Melanura mosquitos and perching songbirds. A mosquito carrying the disease might infect a bird, such as a robin, which may in turn infect another mosquito, which could then infect another bird and so the cycle goes.

But, said Berl, neither the birds nor the mosquitoes tend to die from the disease.

“The best sort of hosts are the ones that aren’t killed by the virus,” she said. “If it kills all the animals, it’s harder to transmit.”

Of the 45 identified species of mosquito in Vermont, Graham said that the disease has only been found in Culiseta melanura, and the chances of this type of mosquito spreading the virus to a mammal are slim.

Graham pointed to a three-year study completed in 2006 by the Connecticut Agricultural Experiment Station. The experiment found that only 4.2 percent of the 100-plus mosquitos sampled had a tendency to feed on mammalian blood. Another 89.6 percent of the mosquitos fed on birds. (PDF can be located here: http://www.ct.gov/caes/lib/caes/documents/biographies/molaeietalajtmh2006.pdf)

The CDC also points out that this type of mosquito feeds mainly on birds and is not likely to pass the EEE virus along to humans. As the CDC puts it, “Transmission to humans requires mosquito species capable of creating a ‘bridge’ between infected birds and uninfected mammals.”

Graham has never found a “bridge” mosquito in Vermont carrying the virus.

And as the heightened need to search for such mosquitos grows, Berl said extra funds to support this work are not currently available.

Andrew Stein

Comments

  1. Josh Fitzhugh :

    Excellent article with some grat quotes, thanks!

  2. Dorian Yates :

    Research has shown that there are alternatives to aerial spraying, which is an antiquated and indiscriminate method of dealing with the 1 type of mosquito that carries EEE. We know that these vector borne diseases will only be increasing in coming years and the State should be planning now for appropriate, safe and sustainable methods to counter the health problems to avoid future emergency spraying., not using antiquated, indiscriminate and unsafe aerial spraying.

    Vermont’s bees are some of the healthiest in the country and the state should be doing all it can to see they remain so. Read Fruitless Fall by Vermont author Rowan Jacobsen to learn more about the plight of the bees.

    Bats, birds and beneficial insects will also be harmed by this aerial application. Here is the full quote from the EPA doc re: bees:
    (3) Non-Target Terrestrial Insects
    Phenothrin has been demonstrated to be highly toxic on an acute contact basis to non-target terrestrial insects, particularly to honeybees. Honeybees may also face indirect dietary risks from phenothrin toxicity. In addition to phenothrin’s high toxicity, the potential for non-target insect exposure to phenothrin is high because phenothrin is most often applied between April to October to control mosquitoes; non-target insects are also at their most active during this time of year. Because of the large exposure potential and high toxicity determination, phenothrin may pose significant acute risks to non-target insects.

  3. Gail Breslauer :

    I’m so sorry that 1 person died and another has been infected with EEE–but spraying 18,000+ acres with a chemical? that is known to kill fish & bees? but “safe”for humans? (Can anyone point me to some well designed, scientific “large population longitudinal research studies” related to people, conducted by folks other than those affiliated with producing or funding this pesticide?)

    Here’s a bit of info I’ve found so far on Anvil 10+10 (Sumithrin), the pesticide being sprayed here in Vermont, via a “crop duster” type of plane from Texas. Purportedly, chemical(s) in this pesticide is/are now linked to possible effects in human endocrine system and might be a hormone interrupter thereby affecting mammary tissue. More/better research is needed. What will it take to end all cancers and all other insidious diseases?

    http://www.bcaction.org/resources/breast-cancer-action-toolkits/ “What you should know about breast cancer and the environment”

    When Massachusetts and New York used this same pesticide, they put out the following information:

    MA: http://www.cmmcp.org/anvil.htm

    NY: http://www.health.ny.gov/publications/2738/

    Please read the following two links–which discuss “chrysanthemums”–and more: http://www.nospray.org/flyers.shtml
    http://www.flcv.com/AnvilTox.html

    I certainly don’t know what the right answer is. I do understand that our state officials are trying to act in our best interests while trying to do the most good, for the most people with the least amount of harm to all (including our food supply chain and all else affiliated with our planet). EEE is certainly scary and a horrible disease–but spraying with pesticides containing chemicals that may not necessarily be “safe” is also scary. One would hope that we might have learned from the past (eg., the spraying of DEET and the “after-the-fact” test results by “outside agencies” who had not produced that pesticide).

    Shouldn’t the federal government’s rules and regs be requiring long-duration, longitudinal, well designed, scientific research studies conducted and validated by folks not affiliated with or funded by any of the companies involved with the production of these chemicals and pesticides–just as happens with other well designed research and clinical trials for various cancers, Parkinsons, Alzheimers, MS and all the other “chronic”, horrible insidious diseases’ treatment drugs?

    These are not easy questions. There are no easy answers or solutions to these problems–but prudent, good science and sharing of all known facts seems to be a “no brainer”.

    My heart goes out to the family and all who knew and loved Mr. Breen, the other hospitalized person–and the folks who asked for a “no fly zone” over their organic gardens/farms.

  4. Rita Phelps :

    How ever, in this case 19 Emus died at one farm from the misquitos. The farm was sprayed and the following year another emu caught the disease and it’s caretaker died, either from being bitten by the misquitos in the area, or from the emu feces. However in that same area another man contacted the disease, through and insect bite, and a third man contacted West Nile Virus. How does the Dept of Health know that the virus has not passed to the human biting missquitos. In Tennessee the CDC tested all of the misquitos in the area by sampling and determined by DNA what they were eating and what they were carrying. Meaning they studied the human biting missquitos, the mamal that has no vacine approved to keep them from dying from the bites. To keep insisting that the misquitos don’t bite human mamals seems antiquated. They did, or they do or the disease has changed. That premis unproven is a huge health risk, and panic spraying a pristine sole aquifer area of an entire town is not solution that appears to me to be viable. In addition you are killing the frogs, bats, salmanders, darning needles, and other insects that eat the swamp mosquitos. In addition we may have the Silent Spring.

  5. Alex Barnham :

    Lest we succumb to the dumb notion that we are suffering from overpopulation and we have to rid ourselves of the “useless eaters”, aerial spraying is just another conspiracy to ruin croplands and the environment. The proof of this is quite evident. For those of you who like to stick your head where the sun doesn’t shine, question why the local hospitals’ parking lots are so full, why we have a huge drug problem in the US, and why politicians are ruining the US economy.

  6. Gaelan Brown :

    This is utter madness. We are being poisoned by our own Dept of Health. When does self-defense come into play here?

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