Big Racial Difference in HIV Diagnosis Nov. 17, 2005 -- Federal officials reported Thursday that the number of Americans diagnosed with human immunodeficiency virus (HIV) declined slightly between 2001 and 2004, though blacks continue to bear the brunt of infections in the U.S.

HIV, the virus that causes AIDS, was diagnosed in 38,685 people in 33 states reporting data to federal officials through the end of 2004. The figure was down slightly from 41,207 diagnoses reported in 2001.

The numbers don't actually reflect the number of new infections across the country because some people who are newly diagnosed may have been infected for years while hundreds of thousands of others are infected but have never been diagnosed.

But the figures give what public health officials say is their best picture yet of the number of Americans who are tested and diagnosed with HIV, a key step to entering treatment and preventing further transmissions.

Overall, officials estimate that approximately 40,000 Americans contract HIV each year, a figure that has not changed substantially for close to a decade despite efforts to track the virus and promote prevention.

Thursday's report shows that HIV diagnosis rates among blacks dropped about 5% per year between 2001 and 2003. But despite the declines, blacks remained more than eight times more likely than whites to test positive.

In all, blacks accounted for 51% of HIV diagnoses during the three years covered in the report though they make up just 13% of the U.S. population, says Lisa Lee, an epidemiologist in the division of HIV/AIDS at the CDC.

Men remain nearly three times as likely as women to test positive for HIV. Researchers also recorded an 8% rise in HIV diagnoses among men who have sex with men -- also known as MSMs -- who comprise the largest single group affected by AIDS.

"HIV continues to exact a tremendous toll on MSM of all races," says Ronald O. Valdiserri, MD, acting director of HIV, STD, and TB prevention at CDC. Agency officials last week reported rising levels of syphilis among men who have sex with men, suggesting that unsafe sex practices may be on the rise in that group.