In a case study published in Eurosurveillance this month, researchers found Zika virus persisted in a man's semen for six months after symptom onset — twice as long as in other reported cases, according to the BBC.
The CDC's current guidelines advise men to wait six months after their Zika symptoms appeared before having unprotected sex with a partner to prevent the spread of the mosquito-borne virus, but these new findings could spur an extension.
"At the light of this new evidence on long-term [Zika virus] RNA persistence in semen, an extension of this interval might be considered," the study's authors wrote.
The World Health Organization plans to look at the study, according to the BBC report.
The CDC started conducting its own study on Zika and semen in July to find how long the virus can stay in semen.
As of Aug. 10, there have been 22 sexually transmitted Zika infections in the U.S.