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NEW YORK (CBSDFW.COM/AP) — For the first time, scientists in South America discovered the presence of an active Zika virus in urine and saliva samples, according to a Brazilian Health Institute.

Scientists don’t know if Zika can be transmitted through these bodily fluids. However it has been confirmed to spread by mosquitos, sexual transmission and, according to Brazilian Health officials, blood transfusions.

In the U.S., health officials said Friday that men who have been to a Zika outbreak region should use condoms if they have sex with a pregnant woman — for the entire duration of the pregnancy. The CDC stressed however that the Zika virus is still mainly spread by mosquitoes.

This advice comes days after a woman in Dallas contracted the Zika virus through sexual transmission. Health officials are also saying four more people in Dallas, who have recently traveled, may have been infected with the Zika virus. Samples from those four patients have been sent to the Centers for Disease Control and Prevention (CDC) and are awaiting results. 

While in most people Zika causes mild or no symptoms, it has become a concern because of a possible link with a birth defect in Brazil.

The CDC has recommended that pregnant women postpone trips to countries with Zika outbreaks, mostly in Latin America and the Caribbean. All travelers are advised to use insect repellent and take other steps to avoid mosquito bites.

The health agency on Friday also updated its guidelines for testing and monitoring pregnant women who have traveled to Zika areas. In the U.S., there have been about 50 cases of travelers diagnosed with the virus, including three pregnant women.

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