The illness is usually mild with symptoms lasting up to a week, and many people do not have symptoms or will have only mild symptoms. It can last a bit longer in urine and saliva, but even that goes away after a couple of weeks, leaving antibody testing of the blood as the only way to determine whether you've had the virus.
A new report from Brazil raises questions about whether the Zika virus can continue to damage an infected infant's brain after birth. It has been linked to more than 1,800 cases of microcephaly in Brazil. But by the age of 7-months, he began to show developmental delays and physical difficulties. The images also show that just because an infant may be born with a normal-sized head, rather than the abnormally small head typical of microcephaly, it doesn't mean their brain has escaped damage from the infection. It is the first known case of a pregnant woman contracting the virus through sexual contact. But he suggested Zika pregnancy registries that the agency has set up - which will follow children born to women infected in pregnancy - may help provide answers. Yockey wonders "if vaginal exposure versus exposure by a mosquito might have different effects-on the fetus, on pregnant women, or on women in general".
The pregnancies considered most at-risk for Zika-related complications are those where the mother is infected in the first trimester of pregnancy, the most intense time in fetal development. The results, published today in the scientific journal Cell, are alarming: Zika could hide and reproduce in vaginal tissue of mice for up to seven days, with an average of four to five days. In March, a report in The New England Journal described the case of a woman who was infected with Zika in her 11th week of pregnancy and continued to test positive for the virus until she terminated the pregnancy 10 weeks later, after tests showed that her fetus suffered from extensive brain damage.
But as these are mice, not people, there are some major differences.
It's another unpleasant surprise about Zika, the once-uninteresting virus that keeps throwing curveballs at researchers.
"I think it's very likely that we'll find that it can infect human brains", he said. Researchers expected to see a response in only the genetically altered mice.
'The vagina is a site where the virus can replicate and possibly transmit to partners.
"If a baby's born and looks normal, we're going to hope that baby is normal", she said. Calcification occurred in several regions of the brain, especially at the junction of the gray matter and white matter, a location not typically seen in other congenital infections.
'Early during pregnancy, if the mother is infected, there is significant impact on the foetus'.
And on August 9, researchers in Brazil also reported on Zika's possible links to serious deformities of joints in the arms and legs of newborns, a condition called arthrogryposis.
"The Zika virus appears to have a niche within the vagina", says senior author Akiko Iwasaki, an immunobiologist at Yale University.
However, Jim Gardner, the vector control manager for the country, said Albopictus mosquito populations, which could transmit the virus, remain high locally.