AMES, Iowa (AP) — Mosquitoes from traps at central Iowa parks have tested positive for the West Nile virus.

The testing was recently conducted at parks in Ames by Iowa State University and the University Hygienic Lab.

While there is a lag time between collecting the samples and the testing, the results suggest mosquitoes with the potential to carry the virus are likely still present in the community. ISU entomologist Ryan Smith says late summer is the peak season for transmission of the virus.

Experts say most people who are infected have no symptoms or experience only mild, flu-like symptoms. The most vulnerable people are those who are at least 50 or have weakened immune systems.

The virus is transmitted to humans through mosquitoes, which acquire the virus by feeding on infected birds.