Technology Reveals Higher Number of New U.S. HIV Infections

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Public Health - October 2008


Tex Med . 2008;104(10):45.

By  Crystal Conde
Associate Editor

New laboratory technology developed by the Centers for Disease Control and Prevention (CDC) shows that an estimated 56,300 HIV infections occurred in the United States in 2006. That estimate differs from the agency's previous estimate of 40,000 because CDC now uses a more precise method for estimating annual HIV incidence.

"These data … provide the clearest picture to date of the U.S. HIV epidemic, and unfortunately we are far from winning the battle against this preventable disease," said CDC Director Julie Gerberding, MD, MPH. "We as a nation have to come together to focus our efforts on expanding the prevention programs we know are effective."

The new estimate comes from the first national surveillance system of its kind based on direct measurement of new HIV infections and builds on a new laboratory test - the BED HIV-1 Capture Enzyme Immunoassay - that can distinguish recent from long-standing HIV infections. The CDC's prior annual HIV incidence estimate used indirect and less precise methods available at the time.

A separate CDC historical trend analysis suggests that the number of new infections was likely never as low as the previous estimate of 40,000 and has been roughly stable overall since the late 1990s.

"It's important to note that the new estimate does not represent an actual increase in the number of new infections, but reflects our ability to more precisely measure HIV incidence and secure a better understanding of the epidemic," Kevin Fenton, MD, director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, said. "This new picture reveals that the HIV epidemic is - and has been - worse than previously known and underscores the challenges in confronting this disease."

CDC's new surveillance system also provides more precise estimates than previously possible of new infections in specific populations. The HIV burden is greatest among gay and bisexual men of all races and African-Americans. 

In 2006, men who have sex with men accounted for 53 percent of those with new infections (28,700), heterosexuals for 31 percent (16,800), and injection drug users for 12 percent (6,600). Infection rates among blacks were seven times as high as whites (83.7/100,000 people versus 11.5/100,000 people) and almost 3 times as high as Hispanics (29.3/100,000 people), a group also disproportionately affected.

"Too many Americans continue to be affected by this disease," Dr. Fenton said. "These new findings emphasize the importance of reaching all HIV-infected individuals and those at risk with effective prevention programs."

In addition to the 2006 estimates, CDC conducted a separate, historical analysis that provides new insight into HIV incidence trends over time, both overall and for specific populations. Results confirm dramatic declines in the number of new HIV infections, from a peak of about 130,000 in the mid-1980s to a low of roughly 50,000 annual infections in the early 1990s.

However, findings indicate that new infections increased in the late 1990s, but have remained roughly stable since that time (with estimates ranging between 55,000 and 58,500 during the three most recent periods analyzed).

"Prevention can and does work when we apply what we know," said Richard Wolitski, PhD, acting director of CDC's Division of HIV/AIDS Prevention. "While the level of HIV incidence is alarming, stability in recent years suggests that prevention efforts are having an impact. In this decade, more people are living with HIV and living longer than ever before due to advances in treatment. Even though this could mean more opportunities for transmission, the number of new infections has not increased overall."

For more information on HIV prevention, click here .

Crystal Conde can be reached by telephone at (800) 880-1300, ext. 1385, or (512) 370-1385; by fax at (512) 370-1629; or by-email at  Crystal Conde .


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