Did HIV Infections Really Increase 50% From 2005?
March 28th, 2008
News reports are breaking that the Centers for Disease Control and Prevention’s 2006 HIV/AIDS Surveillance Report (PDF: 2.6 MB/55 pages) shows a whopping 50% increase in the number of those who are infected with the HIV virus from the previous year. (This figure includes those who are infected with HIV, but who are not yet diagnosed with AIDS.) Regular readers of Box Turtle Bulletin may remember that we reported last November that the CDC had changed how they determined this statistic, and that this new methodology is resulting in a higher estimate than before. We reported:
Before the new regulations took effect, the CDC’s methods for estimating the HIV infection rate was based on actual AIDS diagnoses. But HIV infection and AIDS are two different things: HIV is the virus which leads to an AIDS diagnosis some ten years after infection on average. What the CDC used to do to estimate the rate of HIV infections was to take the actual count of AIDS diagnosis and work backwards from there to arrive at an estimate of HIV infections.
But with the average ten year latency period between infection and AIDS, along with the fact that Highly Active Anti-Retroviral Therapy (HAART) has lengthened this latency period for many people with HIV infection, the estimate has become grossly inaccurate. So now that states are required to report HIV infections as well as AIDS diagnosis, the CDC is getting a much better look at the actual rate of HIV infection.
So far, the CDC doesn’t believe these new numbers represent a significant increase in actual HIV infections.
Page 9 of the 2006 report shows that 52,878 people are reported to have HIV (not AIDS) in 2006. The 2005 report pegged that number at 35,537. However, several large states (California and Illinois, for example) are participating in the names-based reporting system for HIV (not AIDS) diagnoses for the first time. The CDC acknowledges that much of the increase is due to the dramatic rise in the number of states participating in the surveillance program:
CDC officials were emphatic that the higher number of HIV cases reported “do not represent an increase in the epidemic.”
“Instead, it’s more about our surveillance system than any increase,” CDC spokesperson Jennifer Ruth said Friday.
The CDC only recently tied HIV reporting to the amount of money states receive to fight HIV, meaning new numbers are beginning to come in as more states report HIV cases in compliance with CDC standards. In 2005, the CDC’s HIV/AIDS surveillance report included data from 38 states and territories, compared to the 50 states and areas that contributed data to the 2006 surveillance report.
Georgia, which was one of the last states to conform to CDC’s confidential name-based system for reporting HIV cases, ranked eighth in the number of HIV cases reported in 2006, according to the surveillance report.
Data from these new states were not included in the 2005 report.
Other data, specifically the number of actual AIDS diagnoses by year, seems to suggest that the actual prevalence of HIV is not rising nearly so dramatically, if at all. The number AIDS diagnoses has held relatively steady or even slightly downward for the past eight years even as the overall population continues to grow.
There are two ways to interpret this. First, more effective HIV medication may be forestalling the progression of HIV infection to full blown AIDS. But it also suggests that the number of HIV infections leading to those diagnoses may have been fairly stable through the 1990’s. If the number of yearly AIDS diagnoses continues to hold relatively steady over the next several years, then that should validate the belief that there has not been an actual spike in HIV infections.