Story highlights The CDC issued a travel warning after local transmission was reported in Miami

Pregnant women should avoid travel to one Miami neighborhood

(CNN) The Centers for Disease Control and Prevention issued an unprecedented travel warning Monday, advising pregnant women and their partners not to travel to a small community just north of downtown Miami, where Zika is actively circulating. This is the first time the CDC has warned people not to travel to an American neighborhood for fear of catching an infectious disease, according to agency spokesman Tom Skinner.

This week, 11 additional people in Florida were found to have been infected with Zika virus after being bitten by local mosquitoes, bringing the total to 15.

New cases were found by door-to-door surveys of 200 people in their homes and businesses, and they were identified by urine and blood samples that tested positive for the virus or an antibody.

Late last week, Florida health officials confirmed that four people had contracted Zika from mosquitoes in the same 150-square-meter area . It's a mixed-use development with upscale as well as economically stressed businesses and homes, which CDC Director Dr. Tom Frieden said complicates mosquito control efforts.

"New test measurements over the weekend showed a risk of continued active transmission in that area," Frieden said. "Because of this finding, we are advising pregnant women not to travel to that area and if they have traveled there on or after June 15 to visit their health care provider for testing."

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