Risk, Proximity Influential Factors In Endemic Transmission Of HIV

A study led by researchers from the School of Public Health at Georgia State University has found that neighborhoods at high-risk and at low-risk for HIV transmission may have similar social networks but differ greatly in terms of residents’ risk behavior and geographic compactness.

“These results suggest that a ‘minimum’ network configuration may be required for maintenance of endemic transmission, but a particular prevalence level may be determined by factors related to risk, geography, and possibly other factors,” the researchers stated.

The study showed that while social networks in neighborhoods at high-risk for HIV transmission were very similar to those in low-risk neighborhoods, the high-risk neighborhoods had a higher proportion of residents engaging in multiple kinds of risky behavior with multiple others. The high-risk neighborhoods also showed greater geographic compactness and contiguity, meaning the distances between people in high-risk areas were smaller than in the low-risk areas.

The results of the study are published in Sexually Transmitted Diseases in the article “The Human Immunodeficiency Virus Endemic: Maintaining Disease Transmission in At-Risk Urban Areas.” The study’s lead author is Dr. Richard Rothenberg, Regents’ Professor of epidemiology and biostatistics at Georgia State University.

Richard Rothenberg, Regents Professor

Dr. Richard Rothenberg

To test how risk-taking, proximity and social networks contribute to HIV transmission in specific neighborhoods, the researchers interviewed 927 participants within several bordering zip codes in Atlanta between 2006 and 2011. The zip codes were sorted into a high-risk area and a low-risk area, sharing a geographic border of nearly 17 miles. Based on their HIV reporting history at the start of the study, the higher-risk area accounted for 10 times more reported cases than the lower-risk area.

The participant interviews allowed researchers to construct 30 social networks showing connections between the participants, such as how many people in common they had sexual contact or used drugs with. Researchers also measured the geographic distance between participants in the networks.

The high-risk and low-risk areas “differed appreciably with regard to risk and geographic cohesions,” the study stated. However, they were “substantially the same with regard to network properties.”

The data “should not be interpreted to mean that networks are not important,” the researchers stated. “Rather, they might indicate that a certain ‘minimum’ network is required to maintain endemicity,” that is, a state where the disease is regularly found in the population.

The study’s authors also include Dr. Dajun Dai, associate professor of geosciences at Georgia State; and Mary Anne Adams, MSW, and John Wesley Heath, MPH, with the School of Public Health at Georgia State.

111