Emerging Infectious Diseases (Nov 2023)

Prevalence of Undiagnosed Monkeypox Virus Infections during Global Mpox Outbreak, United States, June–September 2022

  • Faisal S. Minhaj,
  • Vijay Singh,
  • Stephanie E. Cohen,
  • Michael Townsend,
  • Hyman Scott,
  • John Szumowski,
  • C. Bradley Hare,
  • Pallavi Upadhyay,
  • Jairus Reddy,
  • Barbara Alexander,
  • Nicolle Baird,
  • Terese Navarra,
  • Lalita Priyamvada,
  • Nhien Wynn,
  • William C. Carson,
  • Solomon Odafe,
  • Sarah Anne J. Guagliardo,
  • Emily Sims,
  • Agam K. Rao,
  • Panayampalli S. Satheshkumar,
  • Paul J. Weidle,
  • Christina L. Hutson

DOI
https://doi.org/10.3201/eid2911.230940
Journal volume & issue
Vol. 29, no. 11
pp. 2307 – 2314

Abstract

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Since May 2022, mpox has been identified in 108 countries without endemic disease; most cases have been in gay, bisexual, or other men who have sex with men. To determine number of missed cases, we conducted 2 studies during June–September 2022: a prospective serologic survey detecting orthopoxvirus antibodies among men who have sex with men in San Francisco, California, and a retrospective monkeypox virus PCR testing of swab specimens submitted for other infectious disease testing among all patients across the United States. The serosurvey of 225 participants (median age 34 years) detected 18 (8.0%) who were orthopoxvirus IgG positive and 3 (1.3%) who were also orthopoxvirus IgM positive. The retrospective PCR study of 1,196 patients (median age 30 years; 54.8% male) detected 67 (5.6%) specimens positive for monkeypox virus. There are likely few undiagnosed cases of mpox in regions where sexual healthcare is accessible and patient and clinician awareness about mpox is increased.

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