Previously, the recommendation has a time frame of at least eight weeks. But the new guidance is based on evidence that the virus could survive in the semen for longer periods than previously thought.
Pregnant women infected by Zika have resulted in severe birth defects, notably associated with undersized head and brain identified as microcephaly. The first case of such kind has appeared in Brazil last autumn. Since then, more than 1,800 cases of deformity have been confirmed.
Last Aug. 26, sexual transmission, mainly through vaginal intercourse, has been reported in 11 countries. In February, the first case of a man catching the virus through anal sex has been documented.
Suspicion of another transmission through oral sex has surfaced in April. According to the WHO, its recent 6-month cautionary step is rather conservative considering that Zika has remained in a man's semen for 188 days after the onset of the symptoms. However, the longest period that the virus has remained infectious was 24 days.
The WHO has also suggested that people in Zika-hit regions should be offered a wide range of contraceptive options in order to have an informed choice about whether and when to become pregnant.
Zika is primarily a mosquito-borne virus that shows no signs of symptoms in four out of five infected cases. The guidelines released on Tuesday has pointed out that mounting evidence sheds light that sexual proliferation is possible and more common than previously assumed.
In related developments, the journal Cell Reports has published that the Zika virus can infect the eyes of fetal, newborn and adult mice.
Michael Diamond, a professor at the Washington University School of Medicine in St. Louis, states that their study has suggested that the eye could be a reservoir for the microbe. He further comments that infected people should be checked for the presence of the virus in their eyes and for how long the infection actually persists.
