By John Dodge

(CBS) — A person contracted the Zika virus after having sex with an infected partner, health officials confirmed.

The patient, who lives in the Dallas area, contracted the virus after having sexual contact with an individual who had returned from a country where the virus is present.

“Now that we know Zika virus can be transmitted through sex, this increases our awareness campaign in educating the public about protecting themselves and others,” said Zachary Thompson, Dallas County Health and Human Services, the director. “Next to abstinence, condoms are the best prevention method against any sexually transmitted infections.”

Typically, the virus is spread after people are bitten by infected mosquitoes.

In medical literature, there has been only one case of Zika transmitted sexually and one case in which the virus was detected in semen, according to Reuters.

In Illinois, two pregnant women are among the three cases of Zika virus in the state. The third case is an adult male and all have traveled to Latin America, according to the state health department. It is believed all three were bitten by infected mosquitoes.

Geographically, Chicago is not at great risk for the type of mosquito that typically carries Zika, says Dr. Mitchell Weinstein of Presence St. Joseph Hospital.

The most common symptoms of Zika virus are fever, rash, joint pain, and conjunctivitis. The illness is usually mild with symptoms lasting several days to a week.

The biggest concern is the risk to unborn children.

The disease has been linked to birth defects and neurological problems, including Guillain-Barre syndrome, which can cause temporary paralysis.

Until more is known about a possible link between Zika virus and birth defects in babies of women who were infected while pregnant, the Centers for Disease Control recommends pregnant women consider postponing travel to areas where Zika virus transmission is ongoing.

Women who are pregnant, or trying to become pregnant, and who must travel to those areas should consult their doctor, and take strict measures to avoid mosquito bites on their trip:

> Whenever you’re outside, use insect repellents that contain DEET or other EPA approved repellents and follow instructions.
> Wear long, loose, and light-colored clothing outside.
> Remove all standing water in and around your home.
> Limit outdoor activities during dusk and dawn hours when mosquitoes are most active.

Officials advise individuals with symptoms to see a healthcare provider if they have visited an area where Zika virus is present or had sexual contact with a person who traveled to an area where Zika virus is present.

There is no specific medication available to treat Zika virus and there is not a vaccine. The best way to avoid Zika virus is to avoid mosquito bites and to avoid sexual contact with a person who has Zika virus.