U.S. health experts cautioned Friday that the apparent discovery of the Zika virus in saliva and urine from people in Brazil does not necessarily mean the virus can be spread by more casual contact with infected people, such as through kissing.

"I think we need to be careful that don't we jump to any conclusions about transmissibility," Anthony Fauci, who leads the National Institute of Allergy and Infectious Diseases, said during an interview on NPR's Morning Edition.

"When you find a virus or fingerprints of a virus in a body secretion, it absolutely does not mean that it is transmitted that way," Fauci said.

The virus may be present in a form that is incapable of spreading, or in such low levels that transmission is impossible or unlikely, several scientists said. There also could be substances present in saliva that prevent the virus from spreading.

"I think it's important to step back and emphasize that Zika is a mosquito-borne virus and the overwhelming majority of cases are spread by mosquitoes," Frieden told reporters during a briefing Friday morning.

The CDC did, however, issue new guidelines for how pregnant women should protect themselves from getting infected, following a report out of Dallas this week that Zika had been spread through sexual contact in one case. - Read More at the NPR

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