The Centers for Disease Control and Prevention (CDC) today warned health providers about the possibility of an mpox resurgence connected to summer festivals and gatherings and said it and local health officials are investigating a cluster of cases in the Chicago area.
Last week, the World Health Organization (WHO) announced an end to the public health emergency phase of the global mpox outbreak, while warning that the battle against the virus isn't over, with transmission persisting in all world regions.
Chicago cluster rises to 13 cases, some with travel histories
Earlier this month, Chicago health providers sounded the alarm about a cluster of seven cases reported since the middle of April. The CDC today in its Health Alert Network statement added more details, including the confirmation of 12 cases and another infection listed as probable mpox.
All were reported to the Chicago Department of Health, and all patients had symptoms.
Of the 13 cases, 9 patients had received two Jynneos vaccine doses. Travel history available for nine patients revealed that four had recently traveled, with locations including New York City, New Orleans, and Mexico. Of the 13 patients, 9 are White, 2 are Black, and 2 are Asian.
The CDC said though vaccine-induced immunity is not complete, immunization is still one of the most important prevention tools and that people who have completed the two-dose regimen may experience less severe symptoms.
Vaccination gaps add to resurgence risks
The CDC warned of a possible resurgence in the spring and summer as people gather for festivals and other events.
It also warned that Jynneos vaccination gaps raise the risk of mpox resurgence. It said though 1.2 million doses have been given, only 23% of the at-risk population has been fully immunized.
Though uptake varies widely by location, the CDC projects that the risk of resurgence is greater than 35% for most locations without stepped-up vaccination or adapting of sexual behaviors to prevent the spread of the virus. "Resurgent outbreaks in these communities could be as large or larger than in 2022," the CDC warned.
As part of outbreak prevention, the CDC urged clinicians to be on the lookout for new cases and to encourage at-risk people to be vaccinated. If healthcare providers suspect mpox, they should order testing, even if the patient was vaccinated or had an earlier mpox infection.
The outbreak in the United States peaked at 460 cases a day in August 2022, then gradually declined. So far, 30,395 cases have been reported, including 42 deaths.