Florida health officials are investigating what could be the first case of locally transmitted Zika virus infection in the continental United States.
Infection with the Zika virus can cause the devastating birth defect microcephaly, which leads to babies born with abnormally small heads and underdeveloped brains.
In a statement released Tuesday, the Florida Department of Health said it was investigating “a possible non-travel related case of Zika virus in Miami-Dade County.”
“The department is actively conducting an epidemiological investigation, is collaborating with the Centers for Disease Control and will share additional details as they become available,” the statement said.
So far, almost all cases of Zika infection in the continental United States — roughly 1,300 — have involved people who traveled to areas where the mosquito-borne disease is circulating.
Brazil has been the epicenter of the Zika epidemic to this point. Infections have also been reported in other Latin American and Caribbean nations.
But U.S. Centers for Disease Control and Prevention officials have said repeatedly that they expect to see cases of local transmission of the Zika virus this summer in southern states with warm, humid climates such as Florida, Louisiana and Texas. The virus is typically transmitted through the bite of Aedes mosquitoes.
In addition to mosquitoes, the Zika virus can be transmitted through sex. The CDC has reported 14 cases of sexually transmitted infections. These infections are thought to have occurred because the patients’ partners had traveled to countries where Zika is circulating, the CDC said.
On Monday, U.S. health officials announced the first case of Zika infection that didn’t involve a mosquito bite or sex. Officials said they were trying to determine how a now-deceased elderly Utah man who had Zika managed to infect a family caregiver.
The Aedes mosquitoes that spread Zika aren’t usually found at the altitudes where the unidentified man lived in northern Utah.
“The new case in Utah is a surprise, showing that we still have more to learn about Zika,” said Dr. Erin Staples, a medical epidemiologist with the CDC working in Utah.
Staples said the infected caregiver recovered quickly. And local Utah authorities said the public shouldn’t fear general Zika transmission.
The deceased patient had traveled to an area outside the country where Zika is circulating and apparently caught the virus there. Lab tests showed he had extremely high amounts of the virus in his blood — 100,000 times higher than that seen in other Zika samples, according to a CDC news release.
Typically, the Zika virus doesn’t cause serious illness. Only about 20 percent of patients notice symptoms.
But Zika can cause serious birth defects if a woman becomes infected while pregnant. Thousands of babies have been born in Brazil with microcephaly. The virus has also been linked to a rare paralyzing condition called Guillain-Barre syndrome.
As of July 13, roughly 1,300 Zika cases had been reported in the continental United States and Hawaii. But none had been caused by local mosquitoes, the CDC said. Most of the infected people had visited countries where Zika is endemic.
The CDC advises pregnant women not to travel to an area where Zika transmission is ongoing, and to use insect repellent and wear long pants and long-sleeved shirts if they are in those areas. Partners of pregnant women are advised to use a condom to guard against sexual transmission during pregnancy.
The U.S. Centers for Disease Control and Prevention provides more information on mosquito-borne diseases.
This Q&A will tell you what you need to know about Zika.
To see the CDC list of sites where Zika virus is active and may pose a threat to pregnant women, click here.