Mpox infections rise to almost double last year’s numbers

Editor’s note: This story has been updated to reflect the comparison time frame for 2023 and 2024.

The number of mpox cases in 2024 is already nearly double the number of cases that were detected in all of 2023.

The most recent data from the Centers for Disease Control and Prevention (CDC) has recorded 582 cases of mpox, formerly known as monkeypox, across all U.S. states and territories in 2024 to date. By the same time in 2023, a cumulative 299 cases were detected.

The Middle Atlantic region — New Jersey, New York, and Pennsylvania — is currently reporting the highest number at 185 cases.

Mpox surged in the U.S. during 2022 when cases spread through the social networks of men who have sex with men. In the U.S., more than 32,000 cases of mpox were detected that year along with 58 total deaths.

When reached for comment, a CDC spokesperson advised against comparing the March 2023 mpox numbers to that of 2024, noting that “the first half of 2023 was an exceptionally low period for mpox case reporting.”

“Reported mpox cases increased slightly in October of 2023 and have remained consistent since then. If you look at trends over the last 6 months, we’ve not seen a “recent” increase in U.S. case reports. For example, from Oct-Dec of 2023, there were 771 cases. From Jan-March 16, 2024, there were 576 cases,” the spokesperson said in a  statement.

The outbreak subsided through outreach and awareness as well as the use of the two-dose smallpox vaccine Jynneos, though access to this shot was hindered at first by limited supplies and poor planning.

Symptoms of the virus are flu-like and include a characteristic painful rash. It is primarily spread through skin contact, but unwashed clothing and bedsheets of an infected individual can also be a vector of transmission.

The public health emergency declaration for the mpox outbreak was allowed to expire in January 2023. Cases of mpox never quite reached zero, however, with the virus continuing to linger in the U.S.

There were concerns last year that a localized spread of mpox cases in Chicago could be the harbinger of a summer resurgence last May, though this ultimately didn’t occur.

Bavarian Nordic, the manufacturer of Jynneos, announced Tuesday that its vaccine would now be commercially available in the U.S.

“Through its existing nationwide vaccine distribution structure, Bavarian Nordic is now making the mpox vaccine commercially available across the nation. As of April 1, health care providers can order JYNNEOS through their preferred wholesaler and distribution partners to make it available for at-risk individuals at local pharmacies and physician offices in addition to public health clinics,” the company said in a statement.

Updated at 5:45 p.m. April 3