It’s little surprise that the Florida Department of Health confirmed this morning that there’s a “high likelihood” that local transmission of Zika has occurred in the United States for the first time, says Anthony Fauci, head of the U.S. National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. “I can tell you right here today I’m almost certain that we’re going to see more,” Fauci said this morning at an event held by the Bipartisan Policy Center in Washington, D.C. “The critical issue is how do you respond to that.”
The four cases appear to have been infected in early July just north of downtown Miami in an area of about 2.5 square kilometers, the Florida health department reported after doing intensive investigations to rule out the possibility that the patients were infected by traveling to affected countries or via sex with infected people.
The department released a map featuring a rectangle where transmission has likely occurred—an area whose boundaries are "NW 5th Avenue to the west, US 1 to the east, NW/NE 38th Street to the north and NW/NE 20th Street to the south," the department says. At a press conference held by the U.S. Centers for Disease Control and Prevention (CDC) in Atlanta later in the day, CDC Director Tom Frieden explained that the area had high levels of the Aedes aegypti mosquito, a species known to spread the Zika virus, although no infected mosquitoes have yet been found.