Mosquitoes testing positive for West Nile virus have been detected in two areas of St. Joseph County.

The St. Joseph County Department of Health says positive mosquito pools were identified in Portage and Penn townships. The Portage Township location is the same area where a positive pool was detected July 9.

Health officials say the discovery serves as a reminder for residents to take precautions against mosquito bites. West Nile virus can cause serious illness in some people.

Residents are encouraged to limit outdoor activity around dawn and dusk, when mosquitoes are most active, and use an EPA-registered insect repellent. Wearing long sleeves and pants can also reduce exposure, particularly in wooded or mosquito-heavy areas.

Health officials are also asking homeowners to eliminate standing water where mosquitoes can breed. That includes emptying water from flowerpots, bird baths, old tires and other containers. Gutters should be kept clear, swimming pools should remain clean and chlorinated, and rain barrels should be properly covered.

The county health department conducts mosquito control efforts, including spraying when a public health threat is detected.

More information about mosquito prevention is available through the St. Joseph County Department of Health.