Hysteria maybe. I made arrangement for my son and his then pregnant wife to come down and visit me last winter. A friend owed me a favor and I had a one week free condo for them in one of the best resorts in the country. When the Zika thing started I advised them to stay home and they did. I'd do it again. A life time is a long time to take care of a handicapped child. In addition they are finding out more about this disease as time goes by including that it can be passed on sexually.
Commonsense told me that it was not in the interest of what is best for Belize so the issue was downplayed. Especially after I read that Belize at the time had no means of testing for Zika. All the countries and Islands around us have Zika but we don't? The lead time for realizing that babies may have the disease is several months so we will maybe shortly seeing the results.
My opinion is that if you are pregnant or plan on being soon do not come down. If not, then don't worry too much about it and continue with your life.
Somewhere on a beach in Belize