New areas of concern include transmissions among people experiencing homelessness and severe cases in immunocompromised persons.
Agam K. Rao, MD, with the Poxvirus and Rabies Branch of the Centers for Disease Control and Prevention, updated the global picture during an annual scientific meeting on infectious diseases: As of Oct. 14, the confirmed worldwide cases number 73,288, with more than one-third of them (27,317) in the United States. Case counts in the United States, however, have been decreasing since early August.
Cases have been most commonly found in men who have sex with men (MSM), though monkeypox has also been diagnosed in cisgender and transgender women, children, and men who do not report recent sex with other men.
Shift away from White men
Dr. Rao described a demographic shift in infections from White, non-Hispanic men early on to non-Hispanic Black and Hispanic men.
“There’s a lot of emphasis right now at CDC to try to understand these spreads, whether they are household [transmission] or another contact. We know that some of the women have had sexual contact with men who were diagnosed with monkeypox,” Dr. Rao said.
In children under age 12, direct skin-to-skin contact with household members seems to be the source, she said. In adolescents, as in adults, the main source seems to be male-male consensual sex.
“And just as in adults, Black and Hispanic children have been disproportionately affected,” she said.
No sustained spread outside MSM
Dr. Rao said that so far there has been no sustained spread detected beyond the MSM community. A CDC study of inmates in Cook County Jail in Chicago at the end of September, she noted, found no secondary cases.
However, health care workers are another group that was suspected to be at higher risk given close contact with patients, although there have been only three confirmed exposures. Sharps injuries from unroofed lesions are tied to some of those confirmed or suspected cases.
“We do not recommend unroofing lesions,” she said. “We’re getting very good samples from just rigorous swabbing of the lesions.”
She said that the CDC is also monitoring “a few hundred” cases, some of them severe, among people experiencing homelessness.
“We are working to try to understand the exposures that have occurred to those individuals and whether transmission has occurred person-to-person,” Dr. Rao said.
Severe cases among immunocompromised
Also of concern are people with compromised immune systems owing to advanced HIV or organ or stem cell transplants.
Among immunocompromised persons, Dr. Rao said, “we’re seeing large necrotic lesions affecting a large percentage of body surface, lesions that continue to develop over weeks.”
Boghuma Titanji, MD, PhD, MSc, a physician-scientist at Emory University in Atlanta, and an emerging-disease specialist, addressed the difference in presentations between immunocompromised and immunocompetent patients.
She said the main distinction is the extent of the lesions. Patients with AIDS and very low CD4 counts, for instance, are presenting with more lesions and have a longer course of illness.
Dr. Rao said in an interview, “It’s really important to understand someone’s immune status and understand whether they are severely immunocompromised. If there is a concern that a person has monkeypox, also testing for HIV concurrently may be important. It could be a missed opportunity to evaluate for it, especially given the fact that these can occur together.”
Assessing the size and appearance of the lesions is important to understanding whether patients could develop severe infection, she said.