According to Southern Seven Health Department's Brad Rendleman, the horse was reported to state authorities on September 5, and was tested shortly afterwards. He said no additional information was provided to them, so it's not known if there were any other horses being kept near the infected animal.

Rendleman said to his knowledge no people have shown any symptoms of the virus, including the horse's owners.

U.S. Health officials say they're convinced this will be the worst year for West Nile virus deaths and severe illnesses since the disease hit America's shores in 1999.

Through Wednesday, there have been 1,405 serious illnesses and 118 deaths reported across the country, with 43 deaths in Texas.

But it's only September and infections are expected to continue into October, even though the height of the mosquito season is over.

The disease is transmitted through mosquito bites, after the insect bites an infected bird.

Rendleman says one in ten people infected will show flu-like symptoms such as fever, headaches, vomiting and diarrhea. Less than 1 percent of those infected will develop serious problems but people older than 50 or those with medical conditions such as cancer, diabetes and high blood pressure are at greater risk for serious illness.

Rendleman says the best way to avoid mosquitoes is to remove standing water from around your home. The insects breed and grow near pools, birdbaths, buckets, and even gutters on homes.

When going outside at dawn or dusk, mosquito repellent that contains 25-35 percent DEET is recommended.

Some portions of this article by Associated Press.