John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Ninety-two percent of new diagnoses occur in just a quarter of U.S. counties, and most of them are urban.
The American HIV epidemic isn't raging as fiercely as it once did, but it's far from being stamped out. That much is evident in the above map showing that in just the past few years, many people across the country were getting their first HIV diagnoses – especially in New York, Los Angeles, Washington, D.C., and all across the Southeast.
This recent assessment of HIV in the United States comes from AIDSVu, a disease-modeling collaboration between the Rollins School of Public Health at Emory University and Gilead Sciences, a provider of HIV treatments. Using newly released data from the CDC, the AIDSVu team created the map to show the "leading edge of the epidemic," says Patrick Sullivan, an epidemiology professor at Emory who helms the project. The eye-opening cartography, which represents new HIV diagnoses from 2008 to 2011, reveals that HIV is being heavily transmitted in certain geographic zones; more than 92 percent of the diagnoses occur in only a quarter of U.S. counties.
Here's the key to the map, which you can access by clicking the gray "New Diagnosis Data" tab at the left of this page:
Going over the entire list of hot spots would take forever, but here's a sampling of the burning ones: Los Angeles County (9,297 new diagnoses); the counties that comprise the Bronx, Brooklyn, and Manhattan (12,854); Cook County, the seat of Chicago (5,716); Baltimore City (2,476); San Francisco County (1,960); Prince George's County, Maryland (1,941); and Wayne County, seat of Detroit (1,504). In a broader sense, HIV continues to pop up all over the East Coast, particularly between Boston and Washington:
And all over Florida:
And is entrenched in Southern California:
What accounts for these trends? The more powerfully affected areas obviously have high population densities – as reported here earlier, 44 percent of AIDS cases over the past few decades centered in only 12 metropolitan regions. In Florida, for instance, the high HIV rate might be explained by large populations in places like Palm Beach, Fort Lauderdale, and Miami. (Before he helped create this map, says Sullivan, "I think I had underappreciated the impact of the epidemic in the Southeast.")
But the prevalence is likely due to a combination of things, including social determinants of health like level of education and ethnicity. "Communities of color, especially African Americans, are disproportionately impacted," says Sullivan. (The CDC has a list of reasons for why that is.) And then there's the all-important issue of money, or more accurately the lack of it.
"Poverty is probably a marker for a set of conditions that favor poor health, generally," Sullivan says. Having no cash means having a difficult time getting access to good healthcare and preventive services. It might also mean people can't pay for the care they get, or might not even have a vehicle to use to travel to a health center.
The takeaway from this fresh look at HIV isn't just that highly populated areas are struggling with the disease. It's that HIV "really has an impact on every part of country," Sullivan says. With luck, the next generation of these maps will be a lot less colorful, as people embrace regular doctor visits and health providers offer better access to HIV screenings. Once a diagnosis is made, folks can do a number of things to minimize the risk of transmission – change their sexual behaviors (like by wearing condoms), for instance, or starting antiretroviral therapy to suppress their viral load and by association their infectiousness.
Some medical professionals are even pushing to have HIV screenings included in routine check-ups, making them as common as testing for cholesterol. "It's an important thing that's coming," says Sullivan, adding that eliminating HIV "can't come soon enough."
Images courtesy of AIDSVu