US extends Zika precaution to 6 months
UNITED States health authorities last week extended to six months a warning to men about the risky time period for sexually spreading Zika virus, which often carries no symptoms but can cause devastating birth defects.
Men who live in or have travelled to an area of active Zika transmission are now urged to wait half a year before attempting conception, regardless of whether they have been diagnosed with Zika or shown any symptoms, the US Centres for Disease Control and Prevention said.
Before, the CDC advised men with possible but unconfirmed Zika exposure - and no symptoms of the virus - to wait eight weeks from the last possible exposure before having unprotected sex.
But in August, officials in Rome reported that Zika could persist in semen for as long as six months, based on the case of an Italian man who was infected with Zika while in Haiti.
The CDC defines possible Zika virus exposure as "travel to or residence in an area of active Zika virus transmission, or sex without a condom with a partner who travelled to or lived in an area of active transmission".
As of Sept 26, Zika was active in 59 countries and US territories, the CDC said.
It also issued a warning on Thursday to pregnant women, recommending they postpone non-essential travel to 12 countries due to "the uncertain risk of Zika virus infection".
The countries are Brunei, East Timor, Cambodia, Indonesia, Laos, Malaysia, Maldives, Myanmar, the Philippines, Thailand and Vietnam.
In general, women who want to become pregnant and who have tested positive for recent Zika virus or unspecified flavivirus infection "should wait at least eight weeks from symptom onset to attempt conception", the CDC said.
If pregnant women are infected with Zika, either by mosquito bite or sexual contact, they face a higher risk of bearing a child with birth defects.