Around 1.3 million people worldwide acquired HIV in 2024, according to UNAIDS. That number has been falling for over a decade but has plateaued in recent years, barely changing from 2023 to 2024. In the United States, an estimated 31,800 new infections occurred in 2022, the most recent year with complete data.
Global Numbers at a Glance
The 1.3 million new infections in 2024 represent real progress compared to the early 2000s, when annual infections were far higher. But the stall in recent years signals that existing prevention efforts aren’t reaching everyone who needs them. Sub-Saharan Africa remains the hardest-hit region by a wide margin. A person born there in 2021 had roughly an 8.7% lifetime probability of acquiring HIV, higher than in any other part of the world. At the same time, sub-Saharan Africa and South Asia have seen the largest drops in both new infections and deaths over the past decade, driven largely by expanded access to testing and treatment.
New Infections in the United States
The 31,800 estimated new HIV infections in the U.S. in 2022 represent a 12% decline from 2018. That downward trend is encouraging, but the virus continues to spread unevenly across the population.
People assigned male at birth accounted for 81% of new infections (about 25,900), while people assigned female at birth accounted for 19% (about 5,900). The age group hit hardest was 25 to 34, with roughly 12,700 new infections in that single bracket. Young adults in their late twenties and early thirties consistently carry the highest burden, likely reflecting a combination of sexual activity patterns and gaps in prevention access during a transitional period of life when many people change healthcare providers or lose consistent coverage.
Why Prevention Has Stalled Globally
The plateau at 1.3 million annual infections reflects a gap between what prevention tools exist and how widely they’re actually used. Effective options like daily preventive medication, condoms, and early treatment of people already living with HIV can dramatically reduce transmission. The challenge is delivering them at scale in the communities where risk is highest, particularly among young women in sub-Saharan Africa and among men who have sex with men, transgender people, sex workers, and people who inject drugs worldwide. Stigma, criminalization, and underfunded health systems all slow progress.
How Preventive Medication Is Changing the Picture
One of the clearest success stories in HIV prevention is PrEP, a daily pill (or now a long-acting injection) that prevents the virus from establishing an infection. In the United States, PrEP coverage rose from just 0.6% of people who could benefit from it in 2012 to 26.3% by 2022. Over that same period, the rate of new HIV diagnoses fell from 13.0 to 10.6 per 100,000 people.
The relationship between PrEP use and declining infections is dose-dependent. States that scaled up PrEP coverage the most saw the biggest drops. States in the top fifth of PrEP expansion saw a 4% decrease in diagnosis rates, while those in the second-highest fifth saw a 1.2% decrease. That pattern strongly suggests PrEP is directly preventing infections, not just correlating with other factors. Still, with only about one in four eligible Americans currently using it, there’s significant room for further impact.
Who Is Most Affected
HIV does not spread evenly. Globally, certain populations face dramatically higher risk due to a combination of biology, behavior, social marginalization, and limited healthcare access. In the U.S., gay and bisexual men and other men who have sex with men remain the group most affected, accounting for the majority of new infections year after year. Black and Hispanic communities are disproportionately represented in new diagnoses relative to their share of the population, reflecting deep-rooted disparities in healthcare access, housing stability, and economic opportunity rather than differences in individual behavior.
Geography matters too. In the U.S., the South consistently reports the highest number and rate of new infections. Globally, eastern and southern Africa carry the largest share of the burden, though the epidemic’s shape varies significantly from country to country.
The Gap Between Infections and Diagnoses
Not every new infection gets counted right away. A meaningful number of people living with HIV don’t know their status, which means they can unknowingly transmit the virus to others. This diagnostic gap is one reason new infections persist even in countries with strong healthcare systems. People who are diagnosed and start treatment quickly reach a point where the virus becomes undetectable in their blood, and at that point they effectively cannot transmit HIV to sexual partners. Closing the gap between infection and diagnosis, through routine testing, at-home test kits, and reduced stigma around getting tested, remains one of the most practical ways to bring annual numbers down further.