At least 30 travelers from Cuba have brought cases of a potentially deadly virus known as “sloth fever” to Florida this year, including 10 just in the past week. The virus, also known as Oropouche, is spread to people by infected biting midges (small flies) and some mosquito species. Health officials and mosquito control staff are on high alert in South Florida, where the species that carries Oropouche, Culex quinquefasciatus, is prevalent.

A new Florida Department of Health report as of Aug. 24 shows five cases reported in each of Broward, Duval and Hillsborough counties, 14 in Miami-Dade, and two in each of Orange, Palm Beach, Pasco, Polk, Lee and Sarasota counties. All cases were from people who had traveled to Cuba.

“People who travel and get bitten, come back and could potentially spread it around,” said Anh Ton, the director of Broward County’s mosquito control. “We are working with other state agencies and the health department to make sure we know when and where there’s a travel-related case, and treat around their residence and business to make sure the person bitten doesn’t spread it.” The virus can be passed to humans only through an insect bite, but if an insect bites an infected person, then bites another person, the virus can be transmitted.

The Centers for Disease Control and Prevention issued an alert on Tuesday to warn travelers to Cuba and Latin America to take extra precautions to prevent bug bites during travel and protect themselves from.