The majority of HIV cases in Atlanta are concentrated in one particular metropolitan area, according to researchers at the Emory Center for AIDS Research (CFAR).

The results, which were presented at the 17th Conference on Retroviruses and Opportunistic Infections in San Francisco last month, showed that 60 percent of cases in Atlanta are found in the downtown area. This “cluster,” or defined geographical area, is characterized by high rates of poverty and behaviors that are known to increase risk of disease, according to CFAR member and research co-author Brooke Hixson.

Data from a 2000 census also identified among the cluster a large population of black residents and a prevalence of drug use, particularly by injection.

Assistant Professor of Medicine at Emory School of Medicine and CFAR member Paula Frew, who authored and presented the research, said in a University press release that the distribution of HIV in Atlanta has not been studied in the past.

The project to examine geographic distribution of HIV in Atlanta began after a group of four researchers did a study on women’s behavioral health, funded by the National Institutes of Health (NIH), that required them to map where women were living and whether or not those areas yielded high HIV and high poverty levels.

“When I was mapping out the HIV prevalence in that study, [the number of HIV cases] seemed more widespread,” Hixson said of the particular cluster she was examining for the previous study. “From that project, we decided to do a statistical study to see if the trend was supported by other data.”

Frew, Hixson and CFAR members Saad B. Omer and Carlos del Rio found that 1.34 percent of people within the downtown cluster had the HIV virus. According to the World Health Organization, a “generalized epidemic” defines places where more than one percent of the population carries the virus.

Hixson said that this percentage is considerably large because outside of the cluster, 0.32 percent of the population are affected by HIV.

“This means that four times as many people inside the cluster have HIV than people outside the cluster,” she explained.

In addition to studying the demographics of the population, the research group also looked at prevention in the area.

Hixson said that although 42 percent of HIV service providers that offer voluntary testing are located in the cluster, the providers are not equally distributed through the area.

“Almost all of the service providers are located in the central downtown area or on the west side of the cluster,” Hixson said, noting that places like DeKalb County do not have many service providers.

Even those places that do have service providers are “overburdened,” she said, because of the high concentration of HIV cases in those areas.

With Georgia ranking ninth in the country for having the most number of HIV/AIDS cases, according to Kaiser State Health Facts, Frew said in the press release that more prevention efforts need to be taken.

“Prevention efforts targeted to the populations living in this identified area, as well as efforts to address their specific needs, may be most beneficial in curtailing the epidemic within this cluster,” Frew said.

This study is important to aid prevention, according to Hixson.

“If we don’t know where people acquiring HIV are living, then we don’t know where to target the services,” she said.

Hixson added that there are a number of ways to help prevent the spread of disease. She suggested that increased efforts such as funding, policy changes and needle exchange programs should be implemented.

“Just having an awareness in the community that HIV is still an issue is important,” Hixson said.

— Contact Alice Chen.