More cases of Zika virus reported in Florida

Zika in Puerto Rico

Florida is reporting more cases of mosquito-borne Zika virus every day this week. Three more cases on Friday make 28 cases in the area so far.

One of the patients on Friday is located outside the one-square mile area of Miami, where the mosquito transmission is thought to be contained.

One of the infections, again, was outside the so-called Zika zone.

"Florida has tested almost 2, 5000 mosquitoes for the Zika virus and has not found one infected mosquito," said CBS News chief medical correspondent Dr. Jonathan LaPook. "It really is like finding a needle in a haystack."

To find out what else Dr. LaPook has to say about the spread of the virus in Florida, watch the video above.