Three new non-travel cases of the Zika virus have been found in Florida, bringing the number of cases confirmed there so far to 28, health officials said.
The mosquito-borne virus can cause microcephaly and other birth defects. "Active transmission" is occurring in a one square mile area of the Wynwood arts neighborhood north of downtown Miami, the Florida Department of Health said.
Of the three new cases, two are in that one square mile area but one is outside the area but still in Miami-Dade County, the health department said.
Health officials still believe that active transmission is only occurring in the area north of Miami.
"One case does not mean active transmission is taking place,” the department said of the case outside the one square mile area.
"The department still believes active transmissions are only taking place within the identified area that is less than one-square mile in Miami-Dade County," the health department said.
Home-grown Zika cases didn't begin showing up until July 29, when the first four were confirmed — the first mosquito-to-human transmissions known to have occurred in the United States.
Zika had already spread fast already across Brazil, Colombia, Venezuela, central America and the Caribbean.
In addition to the non-travel related cases, there were 10 new cases related to travel detected in Florida.
Health officials have confirmed 413 travel-related cases of Zika in Florida, in addition to the 28 infections not believed to be related to travel, the department of health said. Fifty-eight infections involve pregnant women.
The Centers for Disease Control and Prevention say 1,962 Zika cases in the U.S. have been reported as of Aug. 10, the vast majority of which are travel-related.