The AIDS epidemic came to the U.S. in the early 1980s. And for most of the decade that followed, ignorance, fear, and stigma abetted its spread. First, people didn’t even know about the disease. Once they did, they singled out and ostracized the groups that were most obviously affected—gay and bisexual men, intravenous drug users, and members of some immigrant groups. In that environment, it was difficult to get the White House to even talk about the epidemic, let alone secure the resources necessary for research and outreach efforts.

As Michael Hobbes documented in these pages earlier this year, the slow response to the disease was one reason the mortality rate in the U.S. was so much higher than in other countries. But once science found a way to treat the disease, the mortality rate fell. The number of people living with HIV as a chronic condition rose, while the rate of new infections stabilized. Today, the public has a much better grasp of the disease—what it does, how it’s transmitted, what can be done to prevent it. Three consecutive administrations, one of them Republican, have made fighting HIV here and abroad a priority.

But the disease is still around, and it is spreading. About 50,000 people a year get it. And not all of them have easy access to life-sustaining drugs. Officials have proven strategies for slowing the epidemic’s spread and treating those who have it—everything from more widespread testing to establishing a well-structured “care continuum” of drugs and therapy. But for the strategies to work, public health workers must know where to deploy them. That’s why, in 2010, the Obama Administration embraced a new National HIV Strategy. Under this plan, public health officials are supposed to move away from broad, national prevention and treatment efforts—and focus instead on targeting efforts to the communities and people who most need it.

A few years ago, researchers at the Rollins School of Public Health at Emory University, working with Gilead Sciences, devised a way to assist this effort. Using data from the Centers for Disease Control, they developed online, interactive maps depicting where AIDS infections were most prevalent—and where new cases were cropping up most frequently. They called the project AIDSVu. Its principal researcher is Patrick Sullivan, an epidemiologist who worked at the CDC before coming to Emory. The main audience for the maps consists of the people on the front lines—elected officials, public health department leaders, and outreach workers who must make decisions about where to deploy resources and when. “This is powerful,” says Jennifer Kates, vice president and director of Global Health and HIV Policy at the Kaiser Family Foundation. “Maps like those from AIDSVu are a policy tool—something that can help policymakers at all levels understand what is happening in their communities, where they are doing a good job, where they need to do more.”

The latest edition of the maps, which Sullivan has shared with QED in advance of publication, paint a revealing picture of the epidemic—starting with its disparate impact on different regions of the country. The South has just 37 percent of the country’s population, Sullivan notes. But it has nearly 50 percent of the new HIV diagnoses. This isn’t so surprising: New infection rates correlate closely with poverty, and in the South people tend to be poorer than in other parts of the country.