Zika poses long infection risk through sex

The virus that causes Zika fever can be transmitted through sexual contact long after initial infection as it survives for weeks in semen, according to research undertaken in Brazil. A paper published this month in Clinical Infectious Diseases found nine cases of sexual transmission of Zika virus. The initial infections were acquired by men who travelled to regions where Zika is circulating. They then passed it to their partners, who could not have contracted the disease any other way. The virus was identified in the individuals through molecular biological tests. One man still had the virus in his semen 62 days after the onset of symptoms. “It indicates a much larger infectious period during which the virus could be transmitted” than the time it is active in the bloodstream, which is usually no longer than seven days, says lead author José Moreira, a researcher at the National Institute of Infectious Diseases Evandro Chagas,...