Here’s What You Need To Know About Zika As Florida Outbreak Grows

The bad news is that the number of locally-transmitted cases of the Zika virus, which has been linked both to misshaped heads in newborns and Guillain-Barré, a condition that causes paralysis in adults, is on the rise in Florida. The good news is that few public health experts believe the United States is facing anything close to the threat the virus poses to South and Central America and Puerto Rico, all areas where the bug is spreading at a breakneck pace.

The number of locally transmitted cases in a suburb north of Miami has now reached 14, up from four last week. That means the virus has a toehold in Florida, where a one-square mile area has been deemed a no-go for pregnant mothers.

This has prompted U.S. public health officials to issue an unprecedented travel warning Monday, advising expectant women and their partners not to travel to the area where Zika is actively circulating. This is apparently the first time the Centers for Disease Control and Prevention have put out a Zika-related travel warning inside the mainland U.S.

The Florida outbreak comes as concerns about the spread of the virus at the Summer Olympics in Brazil, the epicenter of the outbreak, take center stage ahead of Friday’s opening ceremony. Some athletes, including American cyclist Tejay van Garderen and Australian golfer Jason Day, are skipping the games due to concerns they will contract Zika there. The World Health Organization insists the Olympics would not increase the spread of the virus, but has advised pregnant women to stay away from the games.  

The growing number of Zika cases inside the U.S., plus the warnings from the CDC, have triggered other states where the type of mosquito that transmits the virus are common to issue their own travel warnings. Dr. Neil Silverman, an OB-GYN at the University of California, Los Angeles, is advising expectant mothers to stay away from Miami. Doctors at Baylor College of Medicine in Houston are also considering warning pregnant women and their partners to avoid Miami.

Still, it remains unclear whether local transmission of Zika will spread outside of South Florida. CDC Director Thomas Frieden said the mosquito that spreads Zika — Aedes aegypti — isn’t capable of flying very far. “We can’t predict the future, but we do know that the Aedes aegypti mosquito travels only about 150 meters [about 500 feet] maximum in its life,” Frieden said Monday, adding that he doesn’t expect the current outbreak to spread.

As evidence, he pointed to U.S. outbreaks of two similar mosquito-borne diseases, dengue fever in 2015 and chikungunya in 2014. Both were controlled through mosquito eradication efforts and the widespread use of air conditioning, which keeps mosquitos out of homes.

There are concerns that the virus could spread across the southern U.S., where the mosquito that carries the bug are common. However, a recent study by Michael Reiskind, a North Carolina State University entomologist, found that the chances of getting the bug from a mosquito in North Carolina are virtually non-existent. The South Carolina Department of Health & Environmental Control has also said chances of local transmission in the state are extremely low.

Still, public health officials continue to warn for Americans to take steps to slow mosquito population growth, including setting traps and eliminating standing pools of water. President Barack Obama has asked Congress for $1.9 billion to assist in these efforts, but Congress has yet to appropriate the money.

According to the Centers for Disease Control and Prevention, there are more than 1,600 Zika cases in the United States. The vast majority of these were acquired abroad, but there are a few instances of the bug being transmitted through sexual contact on American soil.

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