Unlike with H.I.V. and other well-known S.T.D.s, it’s not us who will be affected primarily. Zika symptoms are usually mild, if you have any at all. It’s our future children we have to worry about.

One of the few things about Zika we can say for certain is that it can cause severe neurological defects in developing fetuses — primarily a stunting of the skull and brain called microcephaly — and can do so at any time during a pregnancy. An expert who looked at the brain scans of infants with this condition whose mothers had Zika said the babies could not be expected to live very long, and might never be able to recognize their parents.

Some of my friends are getting nervous, and rightfully so. One friend, who recently bought a house in New York State with a stream in her backyard and would like to have a baby, doesn’t know if she should try to get pregnant if Zika breaks out farther north. A classmate who has kids and wants to have another baby in the next few years is hesitant to go on a family vacation to Disney World in Florida.

Of course, these fears rest on the assumption that nothing will be done to stop Zika’s spread.