Via The Globe and Mail: Canada confirms first sexually transmitted Zika case. Excerpt:
Men who have visited a country affected by Zika are being told to use condoms throughout the duration of a partner’s pregnancy or to wait six months before trying to conceive. Men are also being told to use condoms every time they have sex for six months after their return from a country affected by Zika.
But Mark Loeb, an infectious disease expert at McMaster University in Hamilton, said that advice could change, depending on the information that emerges as more research is conducted.
“Guidelines are being built on currently available evidence that is potentially a moving target with more information,” Dr. Loeb said.
Researchers don’t yet know how often the Zika virus is transmitted between sexual partners or whether there is transmission when individuals are asymptomatic. About 80 per cent of those with the virus remain asymptomatic. There are also conflicting reports about the risks to pregnant women, with some estimates suggesting as few as 1 per cent of babies whose mothers are infected with Zika will be born with microcephaly, while others say the number could be as high as 30 per cent, Dr. Loeb said.
“We don’t have the well-defined studies yet,” he said.
For instance, studies have shown that the virus can survive in a man’s semen for up to 62 days, Dr. Loeb said. But if longer studies are conducted, it could turn out the virus survives even longer than that.
Dr. Loeb said he is designing a study that will follow individuals in Nicaragua and Colombia over a period of time to determine how long the virus remains in a person’s body and whether certain health conditions, such as having had dengue fever, have an impact on how long the virus survives.