Evaluation of Public Health Contact Tracing for Mpox Among Gay, Bisexual, and Other Men Who Have Sex With Men-10 US Jurisdictions, May 17-July 31, 2022

Abstract

Objectives. To examine the potential impact of contact tracing to identify contacts and prevent mpox transmission among gay, bisexual, and other men who have sex with men (MSM) as the outbreak expanded. Methods. We assessed contact tracing outcomes from 10 US jurisdictions before and after access to the mpox vaccine was expanded from postexposure prophylaxis for persons with known exposure to include persons at high risk for acquisition (May 17-June 30, 2022, and July 1-31, 2022, respectively). Results. Overall, 1986 mpox cases were reported in MSM from included jurisdictions (240 before expanded vaccine access; 1746 after expanded vaccine access). Most MSM with mpox were interviewed (95.0% before vaccine expansion and 97.0% after vaccine expansion); the proportion who named at least 1 contact decreased during the 2 time periods (74.6% to 38.9%). Conclusions. During the period when mpox cases among MSM increased and vaccine access expanded, contact tracing became less efficient at identifying exposed contacts. Public Health Implications. Contact tracing was more effective at identifying persons exposed to mpox in MSM sexual and social networks when case numbers were low, and it could be used to facilitate vaccine access. (Am J Public Health. 2023;113(7):815-818. https://doi.org/10.2105/AJPH.2023.307301).

FIGURE 1—

Number and Proportion of Mpox Cases Reported and Interviews Conducted Among Gay, Bisexual, and Other Men Who Have Sex With Men in (a) May 17‒June 30, 2022, and (b) July 1‒31, 2022: 10 US Jurisdictions Note. The proportion’s denominator is the total reported for each time period. The 10 jurisdictions were CO, DC, FL, HI, ID, MI, New York City, NC, SC, and WI. ^aNamed contact refers to a close contact in the 21 days after symptom onset for whom the interviewed patient provided sufficient contact information for the health department to initiate a contact tracing investigation. ^bNamed sexual contact refers to a named contact with whom the interviewed patient engaged in sex or close intimate contact.