The threat is serious, as it especially affects an already vulnerable group (i.e., pregnant women), and Florida has already seen cases of the virus. Mosquito-borne viruses and their spread are always a concern, but this particular virus could potentially affect many infants. This isn't some obscure threat to be monitored during foreign trips. The virus being in Florida, which tons of Americans who domestically travel can pass through, adds greater concern.
Yes, the zika virus is a major health threat in the United States. Starting in 2007, the virus began to spread eastward, which led to the 2015-2016 zika virus epidemic. This virus is a mosquito-borne illness like yellow fever or malaria. It is a major health threat in the United States.
Zika is spreading at an alarming rate all over the country, even we mostly hear about pockets of the virus in places like Florida. Children are being born with defects, and we don't even know the effects of exposure yet on women who are thinking about children but aren't pregnant yet.
No, the Zika Virus is not a major health threat in the US. It is more prevalent in other countries than the United States. We should only be concerned about a select few cases that come from Americans traveling to certain countries where Zika Virus is more of a concern.