The Iowa Public Health Department said in a news release Friday that the victim was 81 or older and lived in central Iowa.
It's the first human case of the virus in Colorado for the 2018 mosquito season.
No human cases of West Nile have been reported in Louisville so far this year.
An adult living in Mead is in the hospital for neuro-invasive West Nile Virus - a rare and sometimes fatal form of the illness.
The Department of Environmental Protection said it has found mosquitoes infected with the virus in 51 of Pennsylvania's 67 counties.
The state is checking the case of an Allegheny County resident, sending samples to the Centers for Disease Control and Prevention. Symptoms can include muscle aches, headache and fever.More news: Ohio State's Urban Meyer put on leave, investigation opened
"Luckily, the summer to this point hasn't been extremely wet, which has limited prime breeding conditions for mosquitoes", Callanan said. "You should wear insect repellant if you go outside during dusk or dawn and should remove standing water around your home".
Most infected people don't exhibit any symptoms but if you do you should see a healthcare professional immediately.
Those most at risk for serious complications are people older than 50 and people with suppressed immune systems.
Homeowners are also asked to eliminate standing water by cleaning eaves troughs, emptying bird baths, covering rain barrels with mosquito screens, getting rid of containers that collect water and landscaping for better drainage.
The best way to prevent infection from any mosquito-borne illness, including West Nile Virus, is to use mosquito repellent that contains DEET and by covering up during outdoor activities - wearing shoes, socks, long trousers and a long-sleeved shirt.