“Experience shows that stigmatizing rhetoric can quickly disable evidence-based response by stoking cycles of fear, driving people away from health services, impeding efforts to identify cases, and encouraging ineffective, punitive measures,” Matthew Kavanagh, the deputy executive director of the Joint United Nations Programme on HIV/AIDS, recently said. And as public-health authorities investigate possible links to sexual or other close physical contact at a Pride event in the Canary Islands, a sauna in Madrid, and other gay venues in Europe, government officials are trying hard not to single out a group that endured terrible stigma at the height of America’s AIDS crisis. A disproportionate number of cases in the recent monkeypox outbreak have shown up among gay and bisexual men.