Mosquitos and West Nile

West Nile

The City of St. Louis does not test birds or mosquitoes for West Nile virus because it is considered to be endemic in the area.

For more information about mosquitoes and West Nile virus, including ways to protect against West Nile virus, click here:

Common Sources of Standing Water

Spraying for Mosquitoes

Mosquitoes can carry diseases which threaten the public health, including West Nile virus, and several forms of encephalitis. In an effort to protect public health, the Department of Health (DOH) accepts request and complaints from citizens to spray/fog areas between April-October annually.

The DOH uses a synthetic pemethrin to spray for mosquitoes. It is similar to chemicals found in chrysanthemum extract. It is Aqua-Reslin; an Ultra Low Volume Aerosol. The active ingredients are permethrin and piperonyl butoxide. The chronic toxicity of the product was found through studies not to produce a risk until FAR outside the anticipated human daily consumption and was stated as not indicating a health risk to human beings. The mutagenicity testing resulted in no production of any mutagenic effects. This information was found on the product’s material safety data sheet.

The product the DOH uses to combat mosquitoes has been found to not pose a health risk to humans.

Spraying typically takes place after 8:00 PM which minimizes the impact on bees.