Nearly 5 million people contracted HIV last year, the most infections in a single year since AIDS was discovered, in 1981, the U.N. said this week. “The epidemic is entering its globalization phase,” Peter Piot, director of UNAIDS, said. “The number of new infections is growing, the number of deaths is growing—there’s no real decline.” He urged the 15,000 health experts and researchers who are gathering in Bangkok for the 15th annual global AIDS conference to brainstorm prevention strategies for women and young people, the two fastest-growing segments of the AIDS population. Sub-Saharan Africa and Asia continue to be the source of most new cases.