Since the beginning of the U.S. outbreak, the CDC data show that the vast majority of cases have remained in men. The rates of infection are also very high among transgender men and women. Meanwhile, only about 2% of cases have occurred in women.
Turns out, it takes more than just having sex to keep a monkeypox outbreak going.
In a study, published last month in the journal Science, researchers found that monkeypox spreads at very different rates in different groups of people – and that rate depends greatly on people's sexual activity. Researchers from Nagasaki University and London School of Hygiene & Tropical Medicine built a mathematical model of the global outbreak. Then they looked to see how the number of sexual partners alters the transmission of monkeypox in their network. Overall, monkeypox outbreaks were highly likely in only one particular type of sexual network: where a small number of people have a high number of sexual partners.