How US Health Officials Are Dealing With a Possible Zika Outbreak

— -- This week Florida Health Department officials announced they were investigating two cases of Zika infection in Broward and Miami-Dade Counties -- the first time the virus may have been transmitted in the U.S. by mosquitoes.

If the two cases in Florida are confirmed as being locally-acquired Zika, it will likely reach the threshold set by the U.S. Centers for Disease Control and Prevention to label the area as a "local Zika transmission area." The CDC has different guidelines depending on if there is a single case of local transmission or if there is widespread local transmission.

The Florida Health Department has begun issuing Zika prevention kits for pregnant women and is working with mosquito control to reduce the population of mosquitoes in the area where the two people were infected.

Chalmers Vazquez, operations manager at Miami Dade County Mosquito Control, said officials were taking measures to reduce mosquito populations in the area and were advising all residents nearby to take steps to keep mosquitoes from breeding.

“It’s not going to be out of hands we are under control,” Vazquez told ABC News. “We’re trying to be as aggressive as possible.”

In the event of a locally transmitted Zika outbreak, the CDC will advise community health departments to intensify surveillance and mosquito control and reach out to residents to prevent further infections. The CDC will also provide guidance about Zika infection for anyone living in the affected area.

The CDC urges health departments to work with blood donation centers so donor guidelines can be revised to protect the blood supply from Zika-infected infusions.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, told ABC News that mosquito control can help stop an outbreak by significantly reducing the mosquito population. U.S. health officials had anticipated some small local outbreaks of the virus, he said.

"We expect introductions...and we anticipated that there might be some limited spread locally because we can't swat every mosquito," he explained.

Schaffner noted that the CDC can assist health departments with proper testing if needed.