CDC won't release HIV stats showing higher rates of infection

The official focus of the National HIV Prevention Conference, held Dec. 2-5 in Atlanta, was newly published research on HIV prevention, but the data that generated the most buzz at the conference was not anything on the official program. Days before the conference the Wall Street Journal and the Washington Post ran articles about the Centers for Disease Control and Prevention's (CDC) rumored revised estimate of the number of new HIV infections per year in the United States, an estimate as much as 50 percent higher than CDC's current estimate of 40,000 new infections per year. The Washington Blade first broke the story of CDC's revised estimate last month. But during a press conference Dec. 3 Kevin Fenton, director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, said that CDC would not release the numbers until after the estimate passes an independent scientific review.

Fenton said that the new estimate takes data on new HIV infections in part of the country and uses certain assumptions and mathematical models to extrapolate those numbers and estimate new infections in the country as a whole.

"Any modification to these assumptions during the scientific review will in fact affect the final estimate. ... Given the new and complex nature of the system we have a scientific and an ethical obligation that such a review takes place before the estimates are finalized," said Fenton.

According to the Post, which purports to have spoken with sources familiar with the new estimates, the new data shows that there are as many as 55,000 to 60,000 new HIV infections per year.

Some HIV/AIDS advocates have called on the CDC to release the new numbers immediately. Rebecca Haag, executive director of both the D.C.-based AIDS Action as well as the Massachusetts-based AIDS Action Committee, said the CDC has been using the new estimate privately for at least a year.

"The CDC has been talking about these numbers for a year in private conversation with various people across the country. ... It's been a buzz in the HIV community for about a year," said Haag.

In 2001 the CDC publicly announced an initiative to cut the domestic HIV infection rate in half, but the revised estimate, if as high as media outlets have reported, suggests that those efforts have been a complete failure. Haag criticized the Bush administration for failing to put in place effective HIV prevention policy.

"I think it's a failure on the part particularly of this administration to address the epidemic. The CDC budget has gone down. This administration has not fully funded the methods we know do work, and they have diverted dollars to abstinence-only programs which we know do not work," said Haag.

In terms of the published research presented at the conference, much of it focused on prevention among gay and bi men. Fenway Community Health's Kenneth Mayer presented a study looking at rates of unprotected sex among HIV-positive men in Boston (see "HIV/AIDS prevention gets back on track").

Greg Millett, a behavioral scientist at the CDC, spoke at the Dec. 3 press conference about an analysis he and colleagues did of 53 peer-reviewed studies on HIV infection to try to understand the cause of the disproportionate rate of infection among black men who have sex with men (MSM) compared to their white counterparts.

The review, which examined studies published between 1980 and 2006, found that risk factors alone did not explain the difference. Black and white MSM reported similar rates of unprotected sex, and black MSM in their teens and 20s were one-third less likely to engage in unprotected anal sex than young white MSM. Black MSM had fewer partners than white MSM, and they were less likely to use drugs like crystal methamphetamine thought to put people at higher risk for infection.

Millett said one factor that may explain the higher HIV infection rates among black MSM is related to sex practices during the early days of the epidemic.

"While no difference in rates of unprotected intercourse were seen between black and white MSM since 1990, black MSM were 60 percent more likely than white MSM to report unprotected anal intercourse in the 1980s, in studies that were published in the 1980s," said Millett. "The high prevalence of unprotected sex in the epidemic's early years may have shaped the current epidemic by creating a high HIV background prevalence among black MSM."

He said another factor may be that black MSM were more likely to be infected with a current STD than their white counterparts, which increases the likelihood of HIV transmission. Black MSM were also less likely to be on anti-retroviral therapy, which lowers the levels of virus in the blood and may decrease the likelihood of HIV transmission.