The World Health Organization is calling for further investigation of how Zika may be sexually transmitted.
After a case in Texas appeared to have been passed through sexual contact, WHO spokesman Gregory Hartl said, "We certainly understand the concern. This needs to be further investigated to understand the conditions and how often or likely sexual transmission is, and whether or not other body fluids are implicated," Reuters reports.
The outbreak of the virus, currently spreading through the Americas via mosquitoes, prompted WHO to declare an international public health emergency on Monday.
Zika has been linked to the birth defect microcephaly, in which children are born with abnormally small heads, and WHO will soon distribute advice to pregnant women traveling in affected areas.