Last November, startling and conflicting statistics surfaced regarding the world prevalence and national incidence of HIV.
   
First, the Joint United Nations Programme on HIV/AIDS (UNAIDS) revised its estimate of the number of individuals worldwide living with HIV from 39.5 million to 33.2, an apparent 16% decrease. Later in the same month, numerous leaks of information from the U.S. Centers for Disease Control (CDC) revealed that their estimate for the annual number of new HIV infections in the United States could jump dramatically, from 40,000 to as many as 63,000, an increase of more than 50%. (The CDC report, which has not been released, is currently under extensive peer review.) 


   
In both cases, the new statistics are the result of expanded collection and better interpretation of data. 
   
In the developing world, home to the overwhelming majority of people living with or at risk of acquiring HIV, data is hard to obtain. Most HIV diagnoses occur inadvertently, in hospitals among women giving birth or individuals complaining of what turn out to be AIDS-related illnesses.
   
Even so, India and five sub-Saharan African nations, all among the hardest hit by HIV, recently increased their number of testing sites, which meant they had more data to contribute.  Then, when interpreting data, UNAIDS adjusted for the now apparent disparity between urban and rural rates of HIV infection. 
   
Similarly, in the United States, new federal law requires all states to adopt more precise names-based HIV testing. Also, a new method of blood analysis, called STAHRS, enables researchers to distinguish long-standing infections from recent ones. 
   
As a result, UNAIDS decreased its estimate for global HIV prevalence (the number of people living with the disease) and the CDC may increase its figure for national HIV incidence (the annual number of people newly diagnosed with it). However, the new numbers neither contradict each other nor indicate any trend.  They are simply more accurate than previous estimates. 
   
"Better numbers are always good.  But it is important to recognize that these numbers, while dramatic, only provide new benchmarks," said Judy Auerbach, Deputy Executive Director for Science and Public Policy at the San Francisco AIDS Foundation. "They cannot not be compared to previous figures, and so we'll have to wait several years to discern from them any trends in either global prevalence or national incidence of HIV."
   
Meanwhile, other world statistics remain alarming.  Treatment and prevention programs are still scarce in most of the world.  Since 2003, the President's Emergency Plan for AIDS Relief (PEPFAR) has provided nearly 1.5 million people access to needed HIV medication; but for every individual who has received it, three have gone without; and another three have become newly infected. 
   
President Bush recently proposed $30 billion for the next five years of PEPFAR.  "This represents flat funding for an extremely effective program," said Mark Cloutier, the San Francisco AIDS Foundation's Chief Executive Officer.  "To keep pace with HIV, we must get more people into treatment, improve effective prevention programs based on science, not ideology, and meet the needs of children orphaned by AIDS."
   
Thanks to the Ryan White Care Act and the federal AIDS Drug Assistance Program, half of HIV-positive Americans have access to antiretroviral medications.  However, the higher CDC estimate for annual HIV incidence in the United States underscores the fact that, every year, many thousands more will need them. 
   
"Far more important than the aggregate new number itself," said Auerbach, "is what it can tell us about who, exactly, is becoming infected. Our current statistics already indicate a frightening epidemic for African Americans, especially among men who have sex with men (MSM) and women. That's one area where, nationally, we ought to focus our immediate attention."
   
Under Auerbach's direction, the Foundation's next HIVision Forum on May 15th will convene national experts in San Francisco to discuss the pressing issue of HIV/AIDS in the African-American MSM community. 
   
Unlike UNAIDS and the CDC, the San Francisco Department of Public Health has announced no significant changes in HIV/AIDS statistics, since its surveillance of infectious disease is among the best in the nation. For instance, annual incidence of HIV in San Francisco has remained fairly constant in the last five years, at nearly 1,000 new infections a year.
   
"We're really confronting an endemic here, which poses new and in some respects even more difficult challenges," said Cloutier. "We must refine all our strategies and pilot new ones if we are to reduce the consistent number of new infections, and eventually eradicate HIV."
   
Cloutier highlighted Magnet and the Stonewall Project as laboratories for many of these new strategies. Both merged with the Foundation last June and now provide increased services to gay and bisexual men who comprise almost 90% of new HIV infections in San Francisco.
   
"The new UNAIDS and CDC numbers will provide a better snapshot of HIV and AIDS," said Cloutier. "We need to remember, though, that behind every number are millions of real people facing daily challenges, and too often stigma and suffering.  The revised HIV/AIDS statistics should only increase our dedication to alleviate that suffering, and to create a future without HIV disease."