MIAMI — Two additional Zika infections were confirmed in Florida on Friday, raising the statewide total to 20 reported cases, including seven in Miami-Dade and three in Broward counties, the Department of Health said.

As Zika infections continued to rise in Florida and other states, the nation’s top agency for combating infectious disease issued a new warning about the virus— advising Americans that Zika can be transmitted by a man to his sex partners.

“Sexual transmission of Zika virus is possible, and is of particular concern during pregnancy,” said the advisory published by the Centers for Disease Control and Prevention.

The CDC advises men who might have been exposed to Zika to consider abstaining or using a condom.

Zika is primarily transmitted by Aedes aegypti mosquito bites, though spread of the virus also has been reported through blood transfusions.

As of Wednesday, the CDC had confirmed 52 Zika cases in 16 states and the District of Columbia. In Florida and other states, all Zika infections were acquired outside the country, health officials reported.

None of the Florida cases involves pregnant women, who are considered to be at greatest risk because of a suspected link between Zika virus and microcephaly, a birth defect. The CDC has not reported whether any Zika cases in other states involve pregnant women.

Anticipating the first locally acquired infection, the Florida health department activated a Zika information hot line on Friday (855-622-6735) offering daily updates and answers to questions from the public.

“We have made it a priority to stay ahead of the possible spread of this virus in Florida,” Gov. Rick Scott said in a written statement announcing the hot line.

According to CDC travel advisories, Zika virus is present in Mexico, the Caribbean, Central America and South America. The virus is also present in Cape Verde and in the Pacific Islands.

Zika illness is usually mild with symptoms including a rash, fever, joint pain and red eyes that last from several days to a week. But as Zika spread during the last year through South America and the Caribbean, there have been reports of a spike in microcephaly in babies born to mothers infected with the Zika virus while pregnant.

Scientists are still working to determine whether there is a conclusive link between the virus and microcephaly and other neurological disorders.