The CDC just released some worrisome news about the untreatable Zika virus.
Previously, experts assumed that cases of men infected with Zika passing the virus to healthy female partners via sex were very rare. A new investigation suggests this may be more common than previously assumed.
On Tuesday, the agency said they were investigating 14 possible cases of sexually transmitted Zika virus, several of which were in pregnant women. At least two women were confirmed as having the Zika infection after their only contact with the virus came from sexual contact with a male partner who had recently traveled to an area with Zika.
Earlier in February, the US experienced its first confirmed case of sexually transmitted Zika related to the recent outbreak.
Although the virus is overwhelmingly transmitted by mosquitoes that pick up infected blood from one human and transfer the virus to another, cases of sexually transmitted Zika have been documented in the past.
The CDC is looking into all 14 suspected transmissions. Here's what they know about each one:
- In two women who tested positive for Zika, their only contact with the virus came from sex with a sick male partner who had traveled to an area with local Zika transmission, or areas where the disease is traveling via mosquito.
- Four more women have tested positive for Zika in preliminary tests but are still waiting for tests to confirm they have Zika.
- The other eight are still under investigation.
In all of the above cases, the sick travelers were men who had reported symptoms of Zika within two weeks of when the female partner's symptoms started. Although all cases of sexual transmission so far have come from male partners, interestingly, the CDC added, "At this time, there is no evidence that women can transmit Zika virus to their sex partners; however, more research is needed to understand this issue."
The Zika virus is typically not dangerous to the average person: only about one in five people ever experience symptoms. However, its links to a birth defect called microcephaly, in which babies are born with abnormally small heads, make these reports of sexual transmission troubling for pregnant women.
For that reason, here are the CDC's guidelines on sexual transmission for pregnant women:
- Pregnant women and their male sex partners should discuss potential Zika exposure with the woman's healthcare provider. This includes any history of Zika-like infection.
- Men with a pregnant sex partner who have traveled or live in areas where the virus is being locally transmitted should consistently and correctly use condoms or abstain from sex during the pregnancy.
- Generally, men who have traveled or live in areas with local Zika transmission who are worried about sexual transmission should consider using condoms or abstain.
- The CDC isn't sure how long the risk of sexually transmitted Zika lasts, but said they are looking into answering that question. Zika virus tends to persist for about a week in blood, but it's unclear how long it persists in other bodily fluids like semen or saliva. It's even more unclear if saliva is able to transmit the virus, though there have been reports of Zika virus in saliva samples.