Brazilian scientists detected live Zika virus in human saliva and urine, which may indicate that a person in contact with these bodily fluids can contract the virus.

“I think we need to be careful that don’t we jump to any conclusions about transmissibility,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. “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.”

Saliva can hold HIV, but cannot spread the disease.

Others said the “low levels” can make it “impossible or unlikely” to transfer to another person. Substances in the saliva could also prevent transmission.

“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,” stated Thomas Frieden, head of the Centers for Disease Control and Prevention (CDC).

Aedes aegypti mosquitoes carry the disease. While primarily found in Africa, all but two nations in the Western Hemisphere boast significant populations. (Chile and Canada are the exceptions.) They also carry dengue, yellow fever, and chikungunya. Doctors found the disease in one infant during an autopsy, and numerous mothers reported symptoms.

Experts are working to understand what has now become a clear link between Zika and microcephaly, which occurs when the brain does not form properly during pregnancy as a result of a small skull. This leads to serious mental disabilities. The CDC stated the disorder is typically uncommon.

Doctors reported 404 cases of microcephaly in newborns since November. They tied seventeen “to the Zika virus.” Fifteen of the 404 passed away, “with five linked to Zika.” Authorities are investigating 56 other deaths and 3,670 cases.

The Dallas County Health and Human Services (DCHHS) confirmed a person received the virus after “sexual contact with an individual with Zika.”

“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,” explained Zachary Thompson, DCHHS director. “Next to abstinence, condoms are the best prevention method against any sexually-transmitted infections.”

The CDC published new safe-sex guidelines due to the fear of microcephaly. The scientists told men with Zika to “use a condom or abstain from sex until the baby is born.”

Sperm banks in the United Kingdom and the U.S. have changed policies to protect clients from the Zika virus.

The British Fertility Society asked people who traveled to areas with Zika, mainly South America and the Caribbean, not to donate sperm for 28 days.

The California Cryobank will not allow donations from anyone who traveled to those countries or “have had sex with someone who has traveled there within the past month.” Doctors must report any patient who left the U.S. or Canada. New policy also includes checking all “records on where sperm donors have traveled over the past year to see if any have visited the nearly 30 countries and territories where the virus has caused outbreaks.”