The Centers for Disease Control and Prevention announced on Tuesday that it was investigating whether the Zika virus was transmitted via sex in 14 cases in the United States, including several involving pregnant women. Zika has been linked to thousands of birth defects in Brazil.
In two of the suspected cases, the agency said, the infection has been confirmed in women whose only known risk factor was sexual contact with an ill male partner who had recently traveled to an area where the virus is present.
The reports suggest that sexual transmission may be a more likely means of spreading Zika than had previously been considered, the CDC said.
Testing of the male partners is still pending, it added.
Mosquito bites remain the primary way the virus is spread, although sexual transmission from men to women is possible, according to the CDC. Condoms can help prevent transmission.
The CDC noted that there is no evidence that women can transmit Zika virus to their sex partners.
No cure or treatment exists for Zika, and much about the virus remains unknown, including whether it causes the birth defect microcephaly, a condition marked by unusually small heads that can result in developmental problems.
Brazil on Tuesday raised the number of microcephaly cases linked to Zika. It has confirmed 583 cases of microcephaly, up from 508 a week earlier. Suspected cases rose to 4,107 from 3,935.
The first known case of Zika virus transmission in the US was reported in Texas in early February by local health officials, who said it likely was contracted through sex and not a mosquito bite.
Zika has caused outbreaks in at least 29 countries in the Americas. The CDC added Trinidad and Tobago and Marshall Islands to its travel advisory on Tuesday.
The agency in early February revised its guidelines for pregnant women to include a recommendation that even those without symptoms of the Zika virus should be tested after returning from affected areas.
Photo via Pixabay