The Health Unit has been trapping and testing mosquitoes since June.
Complaints regarding properties with stagnant water in tires, unmaintained swimming pools or other water-holding containers can be reported to the Health Department's Housing and Community Environment program by calling 412-350-4046.
Dallas County reported its first West Nile Virus death of 2018 on Tuesday.More news: Coming this weekend: The most spectacular meteor shower of the year
The Iowa Department of Public Health says West Nile is spread by mosquitoes and can produce symptoms ranging from fever and mild headache to life-threatening inflammation of the brain.
Mosquitoes collected from a trap in Mitchell have tested positive for West Nile Virus, the Perth District Health Unit says.
People older than 50 are at higher risk for severe illness from West Nile virus. They can be infected when they feed on the blood of infected birds.More news: Xiaomi Mi A2 4GB variant launched at Rs 16999 in India
Limit outdoor activities during dawn and dusk, when mosquitoes are most active.
DCHHS recommends that Dallas County residents use an insect repellent containing DEET whenever they go outside, and that they dress in long, loose and light-colored clothing.
Cover up with light-colored clothes, long sleeves and trousers when outdoors or while in areas where mosquito activity is high.More news: Want to see the Perseid Meteor shower?