Text_Files/Eastern_Equine_Encephalitis.txt

EASTERN EQUINE ENCEPHALITIS (cont.) 
Division of Public Health Services  Disease Handbook for Childcare Providers 
Bureau of Infectious Disease Control   REVISED –January 2018 
EASTERN EQUINE ENCEPHALITIS 
 
What is eastern equine encephalitis? 
Eastern equine encephalitis (EEE) is an uncommon 
but serious disease caused by EEE virus.  EEE is an 
arbovirus (short for ar thropod-borne, meaning 
spread by insects).  The virus can be transmitted to 
horses, other animals, and in rare cases, people. 
 
How do people get eastern equine 
encephalitis? 
The EEE virus grows in birds that live in freshwater 
swamps.  The virus has a complex life cycle 
involving birds and a specific type of mosquito, 
called Culiseta melanura.  This particular mosquito 
does not bite people.  Sometimes though, the virus 
can escape from its marsh habitat by means of other 
mosquitoes that feed on both birds and mammals.  
These mosquitoes can transmit the virus to animals 
and people. 
 
What are the symptoms of EEE? 
Infection can cause a range of illnesses.  Most 
people have no symptoms; others get only a mild 
flu-like illness with fever, headache, and sore throat.  
For people with infection of the central nervous 
system, a su dden high fever (103 to  106 ), severe 
headache, and stiff neck can be followed quickly by 
seizures and coma.  About one third of these 
patients die from the disease.  Of those that survive, 
many suffer permanent brain damage and require 
lifetime institutional care. 
 
How soon after exposure do symptoms 
appear? 
Symptoms of EEE usually appear 4 to 10 days after 
the bite of an infected mosquito. 
 
How is eastern equine encephalitis 
diagnosed? 
Diagnosis is based on tests of blood or spinal fluid. 
Who is at risk for eastern equine 
encephalitis? 
Anyone can get EEE, but some people are at 
increased risk, such as people living in or visiting 
areas where the disease is common and people who 
work outside or participate in outdoor recreational 
activities in areas where the disease is common. 
Children and those over age 50 are more susceptible 
to the disease.  The risk of getting EEE is highest 
from late July through September. 
 
What is the treatment for eastern equine 
encephalitis? 
There is no specific treatment for east ern equine 
encephalitis.  Antibiotics are not effective against 
viruses, and no effective anti -viral drugs have yet 
been discovered.  Care of the patient centers around 
treatment of symptoms and complications. 
 
How common is eastern equine 
encephalitis? 
EEE is a rare disease.  An average of 6 cases are 
reported in the United States in most years.  There 
is concern, however, that EEE is re -emerging.  In 
NH, EEE has been found in horses, mosquitoes and 
several species of birds.  In 2014, 3 cases of EEE 
were reported in humans in NH.   
 
How can eastern equine encephalitis be 
prevented? 
A vaccine is available for horses, but not for 
humans.  Prevention of the disease centers around 
controlling mosquitoes and on individual action to 
avoid mosquito bites.  To avoi d being bitten by the 
mosquitoes that transmits EEE: 
• If possible, stay inside between dusk and dawn, 
when mosquitoes are most active 
• When outside between dusk and dawn, wear 
long pants and long-sleeved shirts 


EASTERN EQUINE ENCEPHALITIS (cont.) 
Division of Public Health Services  Disease Handbook for Childcare Providers 
Bureau of Infectious Disease Control   REVISED –January 2018 
 
• Use an insect repellent with DEET or Picaridi n 
according to the manufacturer’s directions 
when outside.  Oil of lemon eucalyptus and 
IR3535 have been found to provide protection 
similar to repellents with low concentrations of 
DEET 
• Clothing can be treated with permethrin 
according to the manufacturer’s directions 
• When possible wearing long sleeves and pants 
while outside 
• Put screens on windows and make sure they do 
not have holes 
• Eliminate standing water and other mosquito 
breeding locations from your property.  Do not 
alter natural water bodies.  The  management of 
ponds and wetlands is regulated by the 
Department of Environmental Services and any 
alterations require a permit before work may 
begin 
 
For more information about eastern equine 
encephalitis, call the New Hampshire Department 
of Health & Hum an Services, Bureau of Infectious 
Disease Control  at (603) 271- 4496 or visit our 
website at www.dhhs.nh.gov
 or the Centers for 
Disease Control and Prevention at www.cdc.gov.