What to know about Oropouche virus — the deadly fever that has reached the U.S.

Medical illustration showing a close-up of a pink viral particle with lots of protrusions sticking out of it. The particle is covered in small yellow dots. Other particles can be seen blurred in the background and the edge of another in the bottom left-hand corner of the image. .

As of Aug. 16, 2024, more than 20 cases of Oropouche virus disease — sometimes nicknamed "sloth virus" — have been confirmed in travelers returning to the U.S. from Cuba.

These are the first known cases in the U.S. of the viral disease, which normally circulates in parts of South America, Central America and the Caribbean. They join a further 19 cases that have also been detected for the first time in travelers returning to Europe from the Americas this summer.