The Centers for Disease Control and Prevention now says women can sexually transmit the Zika Virus to men.
New evidence led the CDC to update its recommendations Monday for how to prevent spreading the virus sexually.
The update comes after the first female-to-male transmission reported in New York City this month.
The virus typically is spread through mosquito bites.
Researchers have been learning more about sexual transmission of Zika.
The CDC also is advising doctors to test pregnant women for two weeks after possible exposure to the virus.
Previously scientists thought the virus could be found in a pregnant woman for only about a week after symptoms started.
This should help doctors pin down whether a patient actually has Zika, which can be difficult to diagnose.