The Zika virus, a mosquito-borne infection linked to birth defects in Brazil, has made its way to Florida and three other states, with one confirmed case in Hillsborough County.
But with only seven cases total in the United States, how much should we worry?
It's worth paying attention to, say health officials, who note the infection can be brought into the country by travelers. Though Zika is not spread person-to-person, the concern is that mosquitoes here can feed on those travelers and potentially bite and transmit the virus to others.
The handful of cases so far — three in Florida, two in Illinois, one each in Texas and Hawaii — involve people who have left the country and returned.
The biggest worry is protecting pregnant women and those intending to become pregnant from mosquito bites, officials say. The Zika infection has been linked to microcephaly, a rare brain birth defect in newborns whose mothers were most likely infected early in their pregnancy. More than 3,500 cases of microcephaly have been identified in Brazil, where Zika is considered epidemic.
"That's a concern for us here because we are a major tourist destination for visitors from the epidemic areas," said Dr. Antonio Crespo, an infectious disease specialist at Orlando Health. The countries most affected are in South and Central America and the Caribbean.
"Someone who is infected could come here to Orlando, for example, making it possible to spread the virus to (Florida)," Crespo said .
According to the Centers for Disease Control and Prevention, the countries besides Brazil dealing with ongoing outbreaks are Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela and Puerto Rico.
Crespo said people who become infected carry the virus for about two weeks after developing symptoms. That's why state and federal health officials are stressing the importance of preventing mosquito bites, dumping standing water around property and reporting Zika symptoms to health care providers. Then extra measures can be taken to spray for mosquitoes and eliminate their breeding grounds.
Mosquitoes in the Aedes species are most likely to transmit the Zika virus and are commonly found in Florida and other tropical climates. They are the same mosquitoes that spread dengue and chikungunya viruses.
"These mosquitoes are resourceful at breeding in containers, puddles, gutters, anything where water collects. And they have a short flight range, so they tend to stay around structures, homes, buildings and people," said Jim Fredericks, chief entomologist and vice president of the National Pest Management Association.
While most mosquitoes are active at dawn and at dusk, the Aedes mosquitoes are different.
"These are very aggressive daytime bitters," Fredericks said. "They can live indoors and outdoors but need to be near people to feed."
Late last month, Puerto Rico reported its first case of locally acquired Zika, meaning the person infected had no known travel history. Last week, Hawaii reported its first case of microcephaly in a newborn whose mother was infected while living in Brazil.
The symptoms of Zika illness include fever, headache and joint and muscle aches, as well as a skin rash and conjunctivitis or pink eye. In most cases, the infection goes unnoticed or the illness is mild and resolves in a week or two. It rarely leads to hospitalizations or death.
"It's a difficult disease to identify clinically because the symptoms are somewhat vague and flu-like," said Dr. Carina Blackmore, deputy state epidemiologist for the Florida Department of Health. "So we may have cases that we don't detect or confirm. The state is working on educational materials for community physicians and public health departments so we can better identify cases."
Doctors at All Children's Hospital Johns Hopkins Medicine in St. Petersburg are following the developments, said Dr. Juan Dumois, who heads the hospital's Division of Infectious Diseases. He said he and his colleagues will be paying particular attention to babies born with microcephaly, a neurodevelopmental disorder characterized by a small head and brain damage.
"If (the mother) has a history of travel," he said, "we can start thinking about Zika."
It will be much more of a challenge to diagnose Zika in children born without the disorder, Dumois added.
Other possible symptoms tend to be "mild and self-limited to a week of fever and headaches."
"It is not usually fatal," he said.
There is no vaccine and no treatment for Zika. Infection is confirmed by a blood test, but because it is such a new infection, no commercial labs carry the test yet. It is available at three state health department laboratories, one of which is on the campus of the University of South Florida in Tampa.
Times staff writer Kathleen McGrory contributed to this report. Contact Irene Maher at firstname.lastname@example.org.