HIV incidence, or yearly new infections, in the U.S has declined about 73% since peaks in the mid-1980s, according to estimates from the Centers for Disease Control and Prevention (CDC).
The report released Thursday resulted from modeling applied to data in the National HIV Surveillance System to determine the number of new annual HIV infections from 1981 to 2019. The agency estimated 2.2 million new HIV infections during the decades-long study period, with about 1.2 million Americans living with HIV infection in 2019.
Results suggest annual HIV incidence increased from about 20,000 infections in 1981 to a high of some 130,400 infections in 1984-1985, before leveling off in 1991-2007 with up to 58,000 infections and dropping to about 34,800 infections in 2019.
"HIV incidence decreased by 73% from the highest annual number of infections (130,400 in 1984 and 1985) to 34,800 in 2019," the report reads.
The CDC says male-to-male sexual contact continues to account for most of infections, making up 63% in 1981 and 66% in 2019, though the proportion of infections tied to heterosexual contact has risen over time, from 2% in 1981 to 22% in 2019. Transgender women also face heightened risks, with a recent CDC report indicating four in 10 transgender women across seven major cities in the U.S. have HIV infection.
Findings also highlight racial and ethnic health care disparities; while HIV infections fell among White people (56% in 1981 to 25% in 2019), the proportion of infections among Black individuals has increased over time from 29% to 41%, in 1981 vs 2019, respectively, and among Hispanic/Latino individuals from 16% in 1981 to 29% in 2019.
Black persons comprised 41% of infections in 2019, but comprised just 12% of the population, and Hispanic/Latino persons made up 29% of infections, and represent 17% of population.
Additional increases were seen among females, with the proportion of infections rising from 8% in 1981 to 18% in 2019.
Results also suggest people who inject drugs account for the largest drop in infections, plummeting 93% from a high in 1988-1990 (34,500 to 2,500 in 2019). The report attributed persistent incidence in the last decade in part to the opioid epidemic, and while syringe service programs helped to drive down HIV infections tied to injection drug use, these programs are not fully available, the CDC said.
"Despite the lack of a cure or a vaccine, today’s HIV prevention tools, including HIV testing, prompt and sustained treatment, preexposure prophylaxis, and comprehensive syringe service programs, provide an opportunity to substantially decrease new HIV infections," CDC researchers wrote. "Intensifying efforts to implement these strategies equitably could accelerate declines in HIV transmission, morbidity, and mortality and reduce disparities."
The agency attributed the decline in incidence over time to boosted availability of diagnostics, routine screening and therapy irrespective of status, use of pre- and postexposure prophylaxis and other tools.
While there is no cure for HIV, antiretroviral therapy (or a preventative medication taken before exposure) was reported with over 99% efficacy in preventing infection and is hoped to further drive down incidence. But, the report noted low percentages in its uptake; just 23% of people were using preexposure prophylaxis in 2019, compared to all those who could benefit from it, with significant racial and ethnic disparities. While White people comprised 63% of prescriptions for preexposure prophylaxis, versus those who could benefit, Black persons made up just 8%, and Hispanic/Latino comprised 14%.
The CDC says the HIV epidemic will not end until health disparities and systemic barriers are addressed.
"Equitable implementation of prevention tools to diagnose HIV infection early, treat persons with HIV to rapidly achieve viral suppression, and link persons to preventive services to reduce new transmissions will hasten the decrease in HIV incidence," the report reads.