Mosquito traps collected from an Ames parks tested positive for West Nile Virus. Iowa State University and the University Hygienic Lab recently conducted testing at parks in Ames. Although there's a lag time between collecting samples and the testing, the results suggest mosquitoes with the potential of carrying West Nile are still present in the community. The most vulnerable people to West Nile are those who are at least 50 or have weakened immune systems.