Ob-Gyn questions? Ask a gynecologist online.
Hello, I'm Dr Manos, M.D., ObGyn. The Zika issue changes everyday. Do you know if you had a mosquito bite in Cancun? If you did you would probably have some symptoms if the insect carried the Zika. Could you spread it to your wife and apparently it can be transmitted with sex. I don't think there is a blood test yet to identify people carrying the virus. There is no vaccine yet. Ask your wife's doctor for their opinion at this point.
It appears to be more of an issue in first trimester and your wife is in second trimester so that's good. We don't know if there could be trouble for the fetus further along. There is an antibody test for Zika that shows up weeks after possible exposure. Should you abstain from sex or use condoms is a consideration. These are concerns that need to be brought up with her doctors. I have no idea when the science catches up to the health emergency that has been declared. Talk to her doctors and do a lot of reading on your own.