LAUSR

BACKGROUND The Ending the HIV Epidemic: A Plan for America initiative aims to reduce new infections by 2030. Routine assessment of incident and prevalent HIV by transmission risk is essential for monitoring the impact of national, state, and local efforts to end the HIV epidemic. METHODS Data reported to the National HIV Surveillance System were used to estimate numbers of incident and prevalent HIV infection attributed to sexual transmission in the United States in 2018. The first CD4 result after diagnosis and a CD4 depletion model were used to generate estimates by transmission category, sex at birth, age group, and race/ethnicity. RESULTS In 2018, there were an estimated 32,600 (50% CI: 31,800, 33,400) incident and 984,000 (50% CI: 977,000, 990,900) prevalent HIV infections attributed to sexual transmission in the United States. Male-to-male sexual contact comprised 74.8% and 69.1% of incident and prevalent HIV infections, respectively. Persons aged 25-34 years comprised 39.6% (12,900; 50% CI: 12,400, 13,400) of incident infections; however, the number of prevalent infections was highest among persons 55 years and older [29.3%; 288,300 (50% CI: 285,600, 291,000)]. There were racial/ethnic differences in numbers of incident and prevalent infections among both men who have sex with men (MSM) and persons with HIV attributable to heterosexual contact. CONCLUSIONS In 2018, most incident sexually transmitted HIV infections occurred in MSM and the burden was disproportionate for persons aged 24-35 years, and Black/African American and Hispanic/Latino adults and adolescents. Efforts to increase use of effective biomedical and behavioral prevention methods must be intensified to reach the goal to end the HIV epidemic in the United States.