Health officials warn of a possible rebound outbreak of Mpox this summer. According to the CDC, "the outbreak is not over." The CDC distributed the following information via the CDC Health Alert Network:

Summary
In the United States, cases of mpox (formerly monkeypox) have declined since peaking in August 2022, but the outbreak is not over. The Centers for Disease Control and Prevention (CDC) continues to receive reports of cases that reflect ongoing community transmission in the United States and internationally. This week, CDC and local partners are investigating a cluster of mpox cases in the Chicago area. From April 17 to May 5, 2023, a total of 12 confirmed and one probable case of mpox were reported to the Chicago Department of Public Health. All cases were among symptomatic men. None of the patients have been hospitalized. Nine (69%) of 13 cases were among men who had received 2 JYNNEOS vaccine doses. Confirmed cases were in 9 (69%) non-Hispanic White men, 2 (15%) non-Hispanic Black men, and 2 (15%) Asian men. The median age was 34 years (range 24-46 years). Travel history was available for 9 cases; 4 recently traveled (New York City, New Orleans, and Mexico).

Although vaccine-induced immunity is not complete, vaccination continues to be one of the most important prevention measures. CDC expects new cases among previously vaccinated people to occur, but people who have completed their two-dose JYNNEOS vaccine series may experience less severe symptoms than those who have not.

Spring and summer season in 2023 could lead to a resurgence of mpox as people gather for festivals and other events. The purpose of this Health Alert Network (HAN) Health Update is to inform clinicians and public health agencies about the potential for new clusters or outbreaks of mpox cases and to provide resources on clinical evaluation, treatment, vaccination, and testing.

Background
A global outbreak of mpox began in May 2022. Previous outbreaks in places where mpox is not endemic were mostly related to international travel; however, this outbreak spread rapidly across much of the world through person-to-person contact, disproportionately affecting gay and bisexual men, other men who have sex with men (MSM), and transgender people. Most patients with mpox have mild disease, although some, particularly those with advanced or untreated HIV infection, may experience more severe outcomes.

As of May 10, a total of 30,395 cases have been reported in the United States. This outbreak had a peak of about 460 cases per day in August 2022, and gradually declined, likely because of a combination of temporary changes in sexual behavior, vaccination, and infection-induced immunity. However, CDC continues to receive reports of new cases and clusters in the United States and internationally.

Currently, CDC does not recommend routine immunization against mpox for the general public.

Mpox vaccination should be offered to people with high potential for exposure to mpox:

- People who had known or suspected exposure to someone with mpox.
- People who had a sex partner in the past 2 weeks who was diagnosed with mpox.
- Gay, bisexual, and other MSM, and transgender or nonbinary people (including adolescents who fall into any of these categories) who, in the past 6 months, have had
- A new diagnosis of one or more sexually transmitted diseases (e.g., chlamydia, gonorrhea, syphilis).
- More than one sex partner.
- People who have had any of the following in the past 6 months
- Sex at a commercial sex venue.
- Sex in association with a large public event in a geographic area where mpox transmission is occurring.
- Sex in exchange for money or other items.
- People who are sex partners of people with the above risks.
- People who anticipate experiencing any of the above scenarios.
- People with HIV infection or other causes of immunosuppression who have had recent or anticipate potential mpox exposure.
- People who work in settings where they may be exposed to mpox.
- People who work with orthopoxviruses in a laboratory.