Pregnant women in American Samoa are being warned against having unprotected sex as part of efforts to stem an outbreak of zika in the territory.
Eight cases of the mosquito borne virus have been confirmed in American Samoa, and that number could rise after test results come in.
Thane Hancock who is leading a team from the Centres for Disease Control and Prevention for the territory said research was still underway into the sexual transmission of the virus.
Dr Hancock said out of thousands of cases confirmed by the centre in other countries, two were pregnant women who contracted zika from their husbands during sex.
"Now that we know about these two cases, the CDC is recommending that women who are pregnant either abstain from sex, so don't have sex during their pregnancy or if they do have sex that they practice safe sex using a condom during their pregnancy."