Long-Term Mpox Sequelae 11 to 18 Months After Acute Illness : A Cohort Study in Two U.S. Cities.

BACKGROUND

Little was known about persistent sequelae of mpox before the 2022 multinational clade II mpox virus outbreak.

OBJECTIVE

To characterize post-mpox sequelae 11 to 18 months after acute mpox diagnosis and compare outbreak-associated psychosocial and behavioral impact between at-risk persons who had or did not have mpox.

DESIGN

Cohort study.

SETTING

New York City, New York, and Houston, Texas.

PARTICIPANTS

Adults attending HIV, pre-exposure prophylaxis, or sexually transmitted infection clinics diagnosed with mpox during May 2022 to January 2023 (post-mpox) or at risk for but never diagnosed with mpox (no-mpox).

MEASUREMENTS: All participants completed psychosocial and behavioral self-assessments. A clinician also assessed post-mpox participants by clinical history and physical examination; persisting mpox physical sequelae were classified by tissue affected and effect on appearance or function. Associations between post-mpox physical sequelae and medical history, acute mpox severity, and sociodemographic characteristics were assessed using marginally adjusted probabilities (presented as risk ratios with 95% CIs).

RESULTS

A total of 154 post-mpox and 201 no-mpox participants were enrolled. The proportion of participants reporting increased psychobehavioral symptoms was generally similar between groups. Fifty-eight percent (89 of 154) of post-mpox participants had at least 1 persistent sequela; 56% (86 of 154) were appearance related, of which 51% (44 of 86) occurred at 2 or fewer sites. Thirteen percent (20 of 154) of post-mpox participants had functional sequelae, of whom 50% (10 of 20) and 35% (7 of 20) had ongoing anorectal and urinary dysfunction, respectively.

LIMITATIONS: Participants may not be representative of mpox-affected and susceptible populations. Findings may over- or underestimate frequency or severity of severe mpox sequelae.

CONCLUSION

Post-mpox sequelae frequently persisted 11 to 18 months after acute mpox, with limited body distribution or physical morbidity but with continued social and sexual effects.

PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention.