The Centers for Disease Control and Prevention just issued a travel warning for people heading to Miami -- specifically, the Wynwood neighborhood north of downtown.
It's the first time the government agency has ever issued a travel warning for a U.S. city because of an infectious disease.
The advisory came after four people from the same small neighborhood tested positive for the Zika virus late last week, CNN reports. They contracted the virus domestically and hadn't traveled. Another 10 have tested positive state-wide.
That means Zika has arrived in the continental United States, and it's starting to spread.
With 40 million travelers...Many can come back who feel perfectly fine. But the virus could be hitchhiking in their blood.
Florida officials said the infected Floridians contracted the virus from mosquitoes within a 150-square-meter area.
The CDC said pregnant women should not travel to Wynwood and pregnant women who live there should be tested.
Officials said June 15 is the earliest day the virus could have been passed on. But many with Zika don't feel any symptoms.
Florida is taking steps to try and eradicate Zika, with the CDC's assistance. Here's what spraying for mosquitoes in a Zika-infested area looks like.
But CDC Director Dr. Tom Frieden said attempts to control the spread of Zika aren't "working as well as we would like." He recommended anyone in the area wear insect repellent, long-sleeved shirts and long pants and removing any standing water.
More Zika coverage from Circa:
- Florida becomes first state with mosquito-related Zika cases
- Utah resident marks U.S.'s first Zika-related death
- South Korea's uniforms come with built-in Zika protection
Here's a look at the Wynwood neighborhood, known for its murals and art galleries.