Amherst Health Department
Summer 2013
Eastern Equine Encephalitis
(EEE)
Frequently Asked Questions
August 13, 2013
1. What is Eastern
equine encephalitis?
Eastern equine encephalitis, or EEE, is a virus that causes
severe inflammation of the nervous system including the brain. The disease occurs in humans and other
animals, but is only transmitted by getting bitten by a certain type of
mosquito; a human cannot get it from another person or animal.
2. Why the increased
concern this summer regarding EEE compared to other years?
This summer a sample of mosquitoes collected in Amherst
tested positive for the EEE virus. Also,
two horses on the Amherst – Belchertown border tested positive. Although no humans have tested positive, this
indicates an elevated risk to people.
EEE is a rare disease, but last summer there were 7 human cases and 8
animal cases in MA.
3. Who can get the
disease and what are the symptoms?
People of all ages
are at risk for infection with the EEE virus, but people over age 50 and
younger than age 15 are at greatest risk for developing severe disease. Most people bitten by an infected mosquito
will not develop any symptoms. Severe cases
of EEE infection begin with the sudden onset of headache, high fever, chills,
and vomiting. The illness may then
progress into disorientation, seizures, encephalitis (inflammation of the
brain) and coma. Approximately a third
of patients who develop EEE die. It
takes 4-10 days after the bite of an infected mosquito to develop symptoms of
EEE. There is no specific treatment for
EEE. Antibiotics are not effective against viruses.
4. Can my dog or cat
get EEE? How do I protect them?
Yes, dogs and cats can get the illness, but it is very
rare. Horses, llamas, deer and alpacas
are susceptible. So are birds such as
ostriches, emus and pheasants and quail. There is a vaccine that is approved
only for horses. The timing is important so speak with your veterinarian to
schedule. Do not use insect repellents made for humans on your dog or cat. They have different metabolism and the
products can be toxic.
5. Is there an EEE vaccine for humans? How do I
protect myself from getting EEE?
There is no human vaccine for EEE. The best way to protect yourself is to keep
mosquitoes from biting you. Reduce the
chances of mosquito exposure by avoiding peak mosquito times between dusk and dawn
and prevent mosquito bites by using repellent and wearing clothing to cover
skin. Please read insect repellent
directions thoroughly to assure safe and effective use.
6. Why is the
happening in our area?
Massachusetts has 51 types of mosquitoes, but not all carry
disease. Amherst has swamps that have
red maple and cedar trees. This is the
habitat of the mosquito that keeps EEE circulating. A different mosquito transmits West Nile
Virus. This mosquito breeds in standing water such as what is found in urban
environments such as around the house, in a bird bath, or catch basin where
runoff water is found from a street.
7. The town’s risk
level was raised. What does this mean?
The Massachusetts Department of Public Health decides when
to raise the risk level for a city or town in the Commonwealth. They make this
determination due to a number of factors that include looking at mosquito
collection data, human clinical cases and veterinary reports.
● A
risk level of High means the conditions are likely to lead to infection of a
person with EEE are occurring in the area. This means people should adjust
outdoor activity to avoid peak mosquito hours from dusk to dawn and avoid
nighttime activities near freshwater swamps where EEE activity is most likely.
8. Is the town going
to cancel or reschedule activities that are held after dusk? Sporting events, for example?
Yes. At this time town sporting events will be rescheduled
to finish before dusk. This decision is made based on the fact that mosquitoes
are attracted to sweat and their habitats are near all of our playing
fields. Likewise, activities such as
sitting on grass to watch a movie will be cancelled. This will continue until
the first frost.
5. Is the town
suggesting residents stay inside after dusk?
No. We are advising that people consider what type of
activity they are participating in and where.
Exercising at dusk in grassy areas has a higher risk for mosquito bites
than a walk on pavement wearing long sleeves and pants. If you choose to engage in activities after
dusk, we hope you will take precautions to keep you and other members of your
group safe by minimizing exposed skin, using repellents if you choose and being
aware of the environment around you.
For more information:
Amherst Health
Department at 413-259-3077
