The first case of the year for the West Nile virus was reported earlier this week in Chicago.

First discovered in Uganda in 1937, the West Nile virus is carried by birds and spread to humans by mosquitoes.

The DuPage County Health Department announced that a local resident in her 50s has contracted the first reported human case of West Nile virus this year.

Department of health epidemiologist, Al DeMaria, told NBC affiliate WHDH that "people should take simple, common-sense steps to protect themselves against mosquito bites and the illnesses they can cause. Use insect repellant, cover up exposed skin, and avoid outdoor activities at dusk and nighttime, when mosquitoes are at their most active. "

Symptoms of the virus include include fever, body aches, headache, joint pains, vomiting, diarrhea or rash. The time from infection to onset of disease symptoms is usually two to 15 days. When someone is infected with West Nile virus, they will typically have one of three outcomes according to the Centers for Disease Control and Prevention: No symptoms, West Nile fever, or severe West Nile disease, such as meningitis or encephalitis. Having no symptoms is the most common outcome, while one percent of people with the virus go on to get meningitis or encephalitis.

CDC reports that most infections in the United States take place between June and September, peaking in August.  Those at greater risk are people older than 50 and those with conditions such as cancer, diabetes and kidney disease, or with organ transplants.

Earlier this week, the Los Angeles Times reported that Dallas County officials declared a state of emergency after the West Nile virus infected at least 190 people, killing ten. Texas has suffered more West Nile deaths than any other state in the nation. About 95 percent of tested mosquitoes in Houston are carrying the virus.

Currently, there is no known cure to treat West Nile virus or vaccines to prevent infection.