Diseases that can be Transmitted by Mosquitoes
While mosquito-transmitted disease is not as common in Minnesota as it
is in tropical climates, there are several diseases of potential concern
to Minnesota residents. Minnesota
residents who travel to other countries can return with tropical diseases
such as malaria or dengue.
- West Nile
West Nile virus is a disease transmitted to people, horses, and birds. It is the most commonly reported mosquito-transmitted disease in Minnesota. Most people infected with West Nile virus show no symptoms or flu-like symptoms, but some (primarily elderly) have more severe illness. West Nile virus was found in Minnesota in 2002 and will remain a public health concern in the foreseeable future.
- La Crosse
La Crosse encephalitis is a viral disease that is transmitted by the Tree Hole mosquito. It has been responsible for an average of 4-5 cases each year in Minnesota, primarily involving severe illness in children.
- Jamestown Canyon Virus (JCV)
Jamestown Canyon virus, which may be transmitted by several different species of mosquitoes throughout Minnesota, is a rarely reported cause of illness in humans. The virus is closely related to La Crosse virus, although disease is reported less frequently and any age group may be affected.
Equine Encephalitis (WEE)
Western Equine Encephalitis is a disease transmitted to people, horses, and birds. It is caused by a virus that is transmitted by the same mosquito species that commonly transmits WNV in western Minnesota. During 1941, there was a large regional outbreak of Western equine encephalitis. There may have been as many as 791 cases in Minnesota that year with 90 deaths. In more recent years, Minnesota has had infrequent and smaller outbreaks of WEE (15 human cases in 1975, single cases in 1983 and 1999).
Equine Encephalitis (EEE)
Eastern equine encephalitis is a rare illness in humans, and only a few cases are reported in the United States each year. Many people infected with EEE virus show no symptoms but some (primarily children) have severe illness.
Louis Encephalitis (SLE)
CDC; Cases of St. Louis encephalitis are usually the result of unpredictable and intermittent localized epidemics. SLE has not been reported in Minnesota since the 1970’s. Attention: Non-MDH link
CDC; Malaria is still a public health concern in North America even though local exposure to the disease hasn’t occurred in nearly 100 years. People who travel to or have lived in other areas of the world may be at risk and should be familiar with the symptoms of the disease and the medications used to prevent infection. Attention: Non-MDH link
CDC; Dengue fever is primarily a tropical disease and rarely occurs within the continental United States. In recent years, Dengue has occurred in southern states, including Texas and Florida. People who travel to or have lived in other areas of the world may be at risk and should be familiar with the symptoms of disease as well as preventive measures used to avoid mosquito bites. Attention: Non-MDH link
CDC; Chikungunya fever is a viral illness not currently found in the United States. The virus is primarily found in Africa and Asia yet was found in 2013 for the first time on the Caribbean islands. People who travel to or have lived in at-risk areas may be at risk and should be familiar with the symptoms of disease as well as preventive measures used to avoid mosquito bites. Attention: Non-MDH link