Starting today, some 20,000 leading HIV/AIDS researchers, policymakers and activists from 200 countries will fill the halls of the Walter E. Washington Convention Center and bring a voice to the experience of millions as the District hosts the International AIDS Society’s global conference, AIDS2012. As hundreds of journalists transmit the story of the conference to the far corners of the world, we in the District will bear witness to this historic gathering of similarly determined minds.

AIDS2012 occurs at a time when the dream of having the wind at our backs in the march against HIV/AIDS may soon become reality. And it is fitting that the District should host the first such conference on U.S. soil in 22 years at such a pivotal time. The region is home to key players in the global response to AIDS, including the Office of the U.S. Global AIDS Coordinator, the National Institutes of Health and the World Bank. AIDS2012 will be an opportunity for the leadership of those major institutions to connect with individuals on the front lines of the fight.

More specifically, though, our city has moved from the systemic failures of yesterday — characterized by waste, fraud and dysfunction — to today’s reality, in which we are cementing our reputation as the model of an aggressive and effective response to this deadly disease.

People in the District are living longer, healthier lives because they are making safer decisions. This is largely due to our work to expand knowledge about the disease in order to combat its spread. From a nationally recognized marketing campaign and a senior citizen peer-education program to new continuing medical education requirements specific to HIV/AIDS and a program that provides objective information on medications, we are creating and making use of new lines of communication to D.C. residents.

According to the recently released update of the D.C. HIV/AIDS, Hepatitis, STD and TB Epidemiology Report, the number of new HIV cases in the District is down 24 percent since 2006, and 76.1 percent of newly infected individuals are connected with care within three months of diagnosis, up from 58 percent in 2006. HIV-related deaths per year dropped from 237 in 2006 to 66 in 2010, and there were zero pediatric HIV diagnoses in 2010. The last figure is particularly impressive, considering that as recently as 2005 the District accounted for nearly 10 percent (six out of 68) of pediatric AIDS cases nationwide.

The annual report makes clear that we still have a tremendous amount of work to do. As reported by The Post, the infection rate among some high-risk/low-income heterosexual women nearly doubled from 2008 to 2010. Much of that increase is likely due to expanded free testing, 122,000 tests last year alone, and our improved reporting systems. But it is a stark reminder that we must continue to innovate and educate to ensure we reach all residents of our city.

There was a time when the District could not pay providers, failed to monitor grants and had no data with which to track the spread of the disease. We now monitor the disease with a name-based reporting system, hold grant recipients accountable for producing results and conduct an annual epidemiological report that guides our progress. Prior failings were a direct consequence of the lack of evidence with which to inform our response and an inability to understand the truth of our epidemic.

AIDS2012’s theme, “Turning the Tide Together,” resonates with our shared experience of HIV/AIDS. Only since we began to view the epidemic as a real threat to us all — black and white, gay and straight, young and old — have we taken the steps together to turn the corner on this deadly disease.

AIDS2012 will be an opportunity to show the world how the District’s data-driven approach is working. At the same time, the diverse experiences of other cities and nations will inform our efforts and enrich our perspective.

This spirit of collaboration — the recognition that people of dramatically different backgrounds are similarly threatened by the disease — and an emphasis on spreading knowledge are essential components of the District’s effective response and will ensure AIDS2012 is a success.

The writer (I-At Large) is chairman of the D.C. Council’s Committee on Health.