April 12, 2016
Dump water-holding containers: Prevention key to reducing mosquito-borne illnesses
Eliminating breeding areas for disease-carrying mosquitoes now can prevent illness this summer
With warmer weather right around the corner, officials with the Minnesota Department of Health (MDH) and the Metropolitan Mosquito Control District (MMCD) are encouraging Minnesotans to remove from their property any small water-holding containers that could fill with rainwater this spring and be used as breeding areas by mosquitoes that can carry disease.
All mosquitoes need water for their eggs. Mosquitoes that carry La Crosse encephalitis, a rare but potentially serious viral disease, commonly lay their eggs in stagnant water inside old tires, buckets, cans, tarps and anything else that can hold rainwater for several weeks. While the kinds of mosquitoes that carry Zika virus have not been found to live in Minnesota, they breed in the same kinds of small containers. Removing water-holding containers helps ensure that those mosquitoes would not get a foothold in Minnesota if they were to ever come here.
“When outdoors this spring, take time to look for water-holding containers on your property,” said Kirk Johnson, Vector Ecologist at the Metropolitan Mosquito Control District. “We still have several weeks before the mosquitoes developing in those containers become adults that can bite people. Containers are also much easier to spot now before tree leaves and growing vegetation come out.”
Containers that people wish to keep (for example, 5-gallon pails, wheelbarrows, children’s wading pools), can be turned over when not in use to prevent the collection of rainwater and any possible use as breeding sites by mosquitoes. Property owners can also look for water-holding holes or depressions in trees (often pockets form where two or more trunks meet near the ground) and fill these with soil or sand to prevent mosquito use.
La Crosse encephalitis can cause severe central nervous system problems in children. An average of between one and six cases are reported in Minnesota each year. Most cases occur in children who live near the wooded or shaded areas in southern Minnesota where the Tree Hole mosquito (the main carrier of this virus) lives.
Zika virus has been associated with severe birth defects in babies whose mothers were infected with the virus. The virus generally results in mild illness or no symptoms at all in children or adults. While 12 Minnesotans have been reported with Zika virus this year to date, all have traveled to countries in warmer regions (Caribbean, Central and South America, and Mexico) where local virus transmission is occurring. The two mosquito species known to carry this virus (Aedes aegypti and Aedes albopictus) are not currently found in Minnesota.
“The attention on Zika nationally has prompted us to re-evaluate our mosquito control efforts and how those efforts can help reduce the risk from La Crosse encephalitis, West Nile virus and other vector-borne diseases,” said Dr. Ed Ehlinger, Minnesota Commissioner of Health. “While the specific kinds of mosquitoes carrying the Zika virus are not currently found in Minnesota, removing water-holding containers helps reduce the risk of serious diseases associated with other kinds of mosquitos that are found here. If Aedes aegypti or Aedes albopictus ever get here, we will be ready.”
None of these container-breeding mosquitoes fly far from where they breed, so it is quite possible for people to keep them away from their homes and families by removing the water sources they require.
“A little bit of container removal work right now can go a long way to protect your family this summer,” said Dave Neitzel, MDH Vectorborne Disease Epidemiologist.
For more information on mosquitoes and mosquito-borne disease prevention, visit the preventing mosquito-borne disease MDH webpage.
For more information on mosquito control in the metro area, visit the MMCD website.