Pregnant women should not have unprotected sex with partners who have traveled to countries in the grips of the Zika virus, federal health officials are warning. The new advice from the Atlanta-based Centers for Disease Control and Prevention comes after news that the virus was transmitted through sexual contact in a case in Texas.

Georgia’s first confirmed case of Zika virus surfaced this week. State and federal health officials are now testing samples from several other Georgians who’ve traveled to areas - mainly Latin America and parts of the Caribbean - impacted by the virus.

Under a new guideline issued by the CDC, pregnant women should not have unprotected sex with any male partner who has traveled to any country in the midst of the current Zika epidemic. Women with sexual partners who have traveled to those countries should require their partners to wear condoms during vaginal, oral or anal sex for the duration of their pregnancies. Either that, or don’t have sex until the baby is born, the CDC said in a statement today.

The agency is expected to issue more guidelines in the next few days specifically aimed at men who are having sex with their pregnant partners. Of concern is the potential link between severe birth defects and the mother’s exposure to the Zika virus.

The rapid spread of Zika is an escalating health crisis in several South and Central American countries and some Caribbean islands. Since last year, the virus — which is most commonly transmitted through mosquito bites — has exploded in Brazil, which is set to host the Olympic Games this summer. It is suspected to be the cause of birth defects in hundreds of newborns in that nation. Microcephaly, a condition marked by an usually small head in infants, has been the most common defect since the outbreak began.

Alarms were raised in the United States this week when the CDC confirmed the first sexual transmission of the virus in a Texas case. In that instance a man, who had recently traveled to Venezuela apparently gave the virus to his partner through sex. While it wasn’t the first time Zika has been passed along sexually in the U.S., it was the first documented case during this outbreak. Even so, CDC doctors insist instances of infection through sex is rare. A mosquito bite by one of two types of mosquitoes, the Aedes albopictus or Aedes aegypti, is far more likely to expose a person to Zika.

Fears were raised even higher on Wednesday when the Georgia Department of Health said a person in the state had tested positive for the virus. While the transmission was travel-related and did not occur on U.S. soil, it still was cause for concern among health officials. It’s unclear whether the person - who officials say has made a full recovery - was symptomatic upon returning to Georgia.

There’s no vaccine for the disease or medicine that will treat or cure it once a person has contracted it.

The Georgia Department of Public Health has also turned over samples to the CDC from several other Georgians who may have been exposed to the virus through travel. As of Thursday, test results were not available and they weren’t expected to all be completed at the same time, GDPH spokeswoman Nancy Nydam said in an email to The Atlanta Journal Constitution.

A person is most contagious when they have symptoms which include fever, joint pain, conjunctivitis and rash. Yet four out of five people have no symptoms, which is one reason health officials are advising extra precautions for sexually active travelers visiting or returning from those affected areas.

Originally found in Africa decades ago, the virus spread to the Pacific Islands. Since last year, the Pacific strain of the virus has exploded in the Americas. Epidemiologists are trying to figure out just how the strain made the jump and then exploded so exponentially.

So far at least 31 cases of the Zika virus have been confirmed in the United States spread across 12 states, from Hawaii to Massachusetts. All have been related to travel. To see the CDC travel guidelines: http://www.cdc.gov/travel