The U.S. Centers for Disease Control and Prevention (CDC) said Tuesday it's investigating 14 new reports of possible sexual transmission of the Zika virus in the country.
Several of the cases involved pregnant women, said the CDC, which published interim recommendations for protecting people against sexual transmission of the Zika virus earlier this month.
In two of the new suspected sexual transmission events, Zika virus infection was confirmed in women whose only known risk factor was sexual contact with an ill male partner who had recently traveled to an area with local Zika virus transmission, the CDC said.
For four additional suspected sexual transmission events, preliminary laboratory evidence is available for the women, but confirmatory tests are pending, it said.
Eight other cases are still under investigation.
"In all events for which information is available, travelers were men and reported symptom onset was within two weeks before the non-traveling female partner's symptoms began," the CDC said in a statement.
"Like previously reported cases of sexual transmission, these cases involve possible transmission of the virus from men to their sex partners."
On Feb. 5, the CDC released guidelines on preventing Zika sexual transmission, following lab confirmation of the first case of virus infection in a non-traveler in the continental United States, who was linked to sexual contact with an infected partner.
The guidance recommended that men with a pregnant sex partner who have resided in or traveled to areas with the Zika virus should use condoms the right way every time during sex or abstain from sex for the entire duration of the pregnancy.
Although sexual transmission of Zika virus infection is possible, mosquito bites remain the primary way that Zika virus is transmitted, the CDC noted.
Because there currently is no vaccine or treatment for Zika virus, the best way to avoid Zika virus infection is to prevent mosquito bites, it said.
