Prevention and Control of Communicable Diseases
Mosquito-Borne Disease (Viral)
Reportable to local or state health departments
This fact sheet is for provider information only.
If you have questions, please call the health department.
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 Period
None. It is not spread person-to-person.
Exclusion
Child Care 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
- 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.
- Wear protective clothing, such as long-sleeved shirts and pants, when outdoors.
- Use an insect repellent with DEET (the active ingredient in most insect repellents) before going outside. Repellents containing DEET (up to 30% concentration for both adults and children; do not use DEET on infants younger than 2 months of age) may be used on clothing or skin. Always follow the label directions. If used properly, most repellents are very safe.
For more information, call the Missouri Department of Health and Senior Services (MDHSS) Bureau of Communicable Disease Control and Prevention at 573-751-6113 or 800-392-0272 (24/7), or call your local health department.