"The first cases of Pneumocystis carinii(jirovecii) pneumonia among young men, which were subsequently linked to HIV infection, were reported in the MMWR on June 5, 1981 (1). At year-end 2019, an estimated 1.2 million persons in the United States were living with HIV infection (2)."
Bosh, K. A., Hall, H. I., Eastham, L., Daskalakis, D. C., & Mermin, J. H. (2021). Estimated Annual Number of HIV Infections ─ United States, 1981-2019. MMWR. Morbidity and mortality weekly report, 70(22), 801–806.