During the early 1980s, as many as 150,000 people became infected with HIV each year. by the early 1990s, this rate had dropped to approximately 40,000 each year, where it remains today.

Advances in Prevention and Treatment

• Drastic reductions in mother-to-child HIV transmission
• New drug combinations to treat HIV and delay the onset of AIDS
• Increased community involvement in HIV prevention efforts
• Better understanding of which communities are at high risk for HIV infection
• Behavioral interventions shown to be effective through randomized, controlled clinical trials

Well-designed and well-delivered HIV prevention programs have contributed to safer behaviors and have helped reduce the number of new infections.

Prevention effectiveness has been proven scientifically. Among those who have benefited are MSM, IDUs, heterosexual men and women at high risk, youth at high risk, and children born to HIV-infected mothers. These results reflect sustained, focused, and collaborative efforts among CBOs, federal agencies, foundations, prevention scientists, and state and local health departments.

Overall Decline in AIDS Cases

AIDS cases have declined dramatically in certain populations and regions. New AIDS cases in the United States increased rapidly during the 1980s, peaked in the early 1990s, and then began to decline dramatically in 1996. The peak in 1993 was associated with expansion of the AIDS case definition. Subsequent declines are most likely the result of improved HIV treatment.

Declines in AIDS Cases in Certain Risk Groups

MSM
It has been estimated that during the mid 1980s, nearly 50% of MSM in some major urban gay communities in the United States were infected with HIV. Although MSM continue to account for the largest number of people for whom a diagnosis of AIDS is made each year, new AIDS cases in this population declined dramatically before stabilizing and then increasing slightly.

IDUs
During the 1980s, injection drug use was another major route for HIV transmission in the United States. After more than a decade of prevention interventions—drug treatment programs, needle exchange programs, safer injection practices, peer support, street outreach, and counseling—new AIDS cases in IDUs declined.

Declines in AIDS Cases in Children

The estimated number of US children with AIDS declined 94% from 1992 (when the number of cases peaked) through 2003. This decline reflects the use of antiretroviral therapy to prevent HIV transmission from mother to child.

Declines in AIDS Cases in Geographic Regions

In most US regions, new AIDS cases were first observed to decline in 1996. More recently, from 2002 through 2003, the number of AIDS cases increased in the Northeast, South, and Midwest and decreased in the West.