Prevention and Control of Communicable Diseases - Missouri ...

July 2011
MOSQUITO-BORNE DISEASE (VIRAL)
Reportable to local or state health departments
153
PROVIDER
Mosquito-borne diseases are viral diseases that are spread by infected mosquitoes. Each disease is caused
by a different virus. The many viruses have the potential of causing serious disease affecting the brain and
central nervous system. Removal of potential breeding sites is important in preventing the spread of
mosquitoes.
CAUSE West Nile virus (WNV) flavivirus
Eastern Equine encephalitis (EEE) alphavirus
Western Equine encephalitis (WEE) alphavirus
Saint Louis encephalitis (SLE) flavivirus
California Group (i.e. La Crosse ) bunyavirus
SYMPTOMS May not be apparent or may range from mild headaches and influenza-like
symptoms (such as fever, malaise, tiredness, headache, stiff neck, nausea,
vomiting, rash, or muscle aches) to mental confusion and convulsions. Severe
cases may develop inflammation of the brain (encephalitis). Most infections do
not progress to encephalitis.
SPREAD Each virus is spread through the bite of a specific species of mosquito. West Nile
disease may be spread by blood transfusion and transplanted organs. Some
mosquitoes are weak flyers and tend to live close to their hatching sites.
Birdbaths, wading pools, dog bowls, and other artificial containers of water should
be emptied weekly to eliminate mosquito-breeding areas. Road ditches should be
properly graded to allow water to drain. Rain gutters should be cleaned annually
(every spring). Tires are notorious breeding places for mosquitoes.
INCUBATION The incubation period is usually 2 to 6 days, but ranges from 2 to 14 days, and
may be up to 21 days in immunocompromised people.
CONTAGIOUS None. It is not spread person-to-person.
PERIOD
EXCLUSION Childcare and School: None.
DIAGNOSIS Recommend parents/guardians call their healthcare provider if symptoms of
arboviral disease are present. A healthcare provider must make the diagnosis.
TREATMENT Recommend parents/guardians call their healthcare provider.
PREVENTION/CONTROL
This fact sheet is for provider information only.
If you have questions, please call the health department.
� Eliminate potential breeding sites. Mosquitoes breed in water and artificial
containers, especially flower pots, birdbaths, cans, children’s toys, wading pools,
tire swings, old tires, or anything that will hold a small pool of water should be
emptied or discarded. Old tires should be sent to a recycling center for proper
disposal. Gas stations or tire stores may be a potential drop-off site.