Mpox Without Sex Between Men: Possible Exposures Among 52 Patients, 2022

The 2022 mpox outbreak hit gay, bisexual and other men who have sex with men hardest, but about 30 percent of U.S. patients did not report male-to-male sexual contact. How did they catch it? CDC and six health departments looked closely at 52 such patients diagnosed from November 1 to December 14, 2022.

The patients

The six jurisdictions were California (outside Los Angeles County), Georgia, Louisiana, New York City, Pennsylvania (outside Philadelphia) and Philadelphia. Of 932 mpox cases reported nationally in the period, 122 came from these places and met the first criteria; after excluding people who did not have mpox, those for whom male-to-male contact was reported or could not be ruled out, and those with no exposure data, 52 remained. Health workers reviewed their records and reinterviewed as many as they could.

• Median age 36 (range 18–70); disproportionately Black and Hispanic; about a quarter unemployed and more than 1 in 10 without secure housing.
• 48 of 49 with information had a rash, most often starting on the genitals (48 percent), then the legs, arms and trunk.
• 8 of 32 with known HIV status had HIV; 3 of 30 with known vaccination status had received at least one JYNNEOS dose.

A known exposure: 14 patients

Fourteen patients (27 percent) had been exposed to someone with suspected or confirmed mpox — eight through sex or other intimate contact, six through living in the same household.

A household cluster. A man (patient A) was arrested and held for five days in a jail cell with up to seven others, one of whom reportedly had typical mpox lesions on the arms and shared the cell, water fountain, bench and toilet with him for more than 10 hours. His symptoms began the day after his release. He had sex with his female partner (patient B), whose symptoms began a week later. The two shared a home with a woman (patient C) and a preschool-aged child, both of whom got mpox — patient C two weeks after patient B, and the child, whom patient C cared for, a week after that.

Other exposures reported by this group included:

• Caregiving. Patient D cleaned her son's home while he was in the hospital with mpox. She did not live with him and had no direct contact with him there, wore gloves only inconsistently after learning of his diagnosis, and later developed lesions on her hand.
• Work. Patient E, a property manager, had skin-to-skin and close face-to-face contact with a client who had mpox, and handled objects the client had shared or possibly contaminated; neither wore protective equipment.
• Close conversation. Patient F spent 1.5 hours within 6 feet of a friend with mpox at an indoor bar or restaurant, unmasked, though without touching or sharing food or drink. Whether the friend was acutely ill at the time is unclear.

No known exposure: 38 patients

The other 38 (73 percent) knew of no contact with anyone who had mpox. In the three weeks before falling ill:

Self-reported activities of the 52 patients, by whether they had a known exposure. Credit: CDC, Morbidity and Mortality Weekly Report.

Six of the 17 reported sex only with a partner or spouse who did not have mpox, so sex may not have been their source. Only one patient reported nothing but casual contact: living alone, going to a bar and using a rideshare, with no close contact with anyone. For most, the source could not be pinned down, and several had close contact with people who may have had unrecognized or undisclosed mpox — which can spread before symptoms appear.

What it means

Sex and other close skin-to-skin contact remained the main route of infection even for people who did not report male-to-male sex, but household spread, possibly through contaminated objects and surfaces, happens too. For people sharing or visiting a home with someone who has mpox, the advice is good hand hygiene, following cleaning and disinfection guidance, and not touching possibly contaminated surfaces or sharing bedding, clothing, towels or utensils. Anyone with close contact should watch for symptoms for 21 days, get vaccinated as soon as possible, and see a provider promptly about a new or unexplained rash. Vaccination and outreach should focus on the communities hit hardest, to limit health disparities.

Limits

Exposures were self-reported; the six jurisdictions may not represent others; and the sample was small, with much missing information.

Sources

Based on "Possible Exposures Among Mpox Patients Without Reported Male-to-Male Sexual Contact — Six U.S. Jurisdictions, November 1–December 14, 2022," by J. Danielle Sharpe, Kelly Charniga and colleagues (CDC and six state and local health departments), Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention; a work of the United States government in the public domain.