|Points Of Contact
|Assistant to Director for Science
|Assistant to Director for Field Operations
|National Capitol Region
|Pacific West Region
Eastern, Lacrosse, St. Louis & Western encaphalitis
Encephalitis is an inflammation of the brain, which
can be caused by viruses transmitted through the bite of an infected mosquito.
Susceptibility to clinical disease is highest in infancy and old age.
With an incubation period between 5 and 15 days, mild cases result in
a febrile headache while severe cases present with acute onset of high
fever and headache, but most infections are asymptomatic. Case fatality
rates range from 0.3% to 60% with Eastern Equine exhibiting the highest.
Each disease is caused by a specific virus, occurs in specific geographic
regions, transmitted by specific species of mosquitoes and may follow
certain cyclic patterns based on multiple environmental factors.
Effective risk reduction for mosquito-borne diseases within the NPS requires
all employees and visitors to be knowledgeable and proactive in taking
necessary steps to minimize exposure. Primary risk reduction practices
include eliminating man-made mosquito-breeding habitat, avoiding activities
when mosquitoes are most active, and wearing long sleeved shirts and pants.
Many species of mosquito breed in stagnant water, therefore, it is critical
that containers such as tires, buckets, birdbaths, gutters and miscellaneous
debris are either removed or not holding water. The use of an insect repellant
containing DEET, picaridin or oil of lemon eucalyptus (p-menthane or PMD)
are effective against mosquitoes and should be used during periods of
high mosquito activity. DEET should be used with caution on children –
DEET is not recommended for the very young. Products containing oil of
lemon eucalyptus should not be used on the very young.
If you have any questions, please contact your nearest Regional Point of Contact,
park sanitarian or call WASO Public Health for more information.
Health Information, National Center for Infectious Diseases, Centers for
Disease Control and Prevention, Department of Health and Human Services.
Return to Vectorborne and Zoonotic Infectious Agents Page