BACKGROUND: To reduce health disparities and improve the health of Americans overall, addressing community-level social and structural factors, such as social vulnerability, may help explain the higher rates of HIV diagnoses among and between race/ethnicity groups. METHODS: Data were obtained from CDC's National HIV Surveillance System (NHSS) and the CDC/ATSDR social vulnerability index (SVI). NHSS data for Black, Hispanic/Latino, and White adults with HIV diagnosed in 2018 were linked to SVI data. To measure the relative disparity, rate ratios (RRs) with 95% CIs were calculated to examine the relative difference comparing census tracts with the lowest SVI scores (quartile 1, Q1) to those with the highest SVI scores (quartile 4, Q4) by sex assigned at birth for age group and region of residence. Differences in the numbers of diagnoses across the quartiles were analyzed by sex assigned at birth and transmission category. RESULTS: There were 13,807 Black, 8747 Hispanic/Latino, and 8325 White adults who received a diagnosis of HIV infection in the United States in 2018-with the highest HIV diagnosis rates among adults who lived in census tracts with the highest vulnerability (Q4). For each race/ethnicity and both sexes, the rate of HIV diagnoses increased as social vulnerability increased. The highest disparities in HIV diagnosis rates by SVI were among persons who inject drugs, and the highest within-group RRs were typically observed among older persons and persons residing in the Northeast. CONCLUSION: To reach the goals of several national HIV initiatives, efforts are needed to address the social vulnerability factors that contribute to racial and ethnic disparities in acquiring HIV and receiving care and treatment.

We examined the association between social vulnerability and HIV diagnoses, linkage to HIV medical care, and viral suppression among adults in the Southern U.S. Data from CDC's National HIV Surveillance System (NHSS) were used to determine census tract-level HIV diagnosis rates and percentages of persons linked to care within one month and with viral suppression within six months of diagnosis among Black/African American, Hispanic/Latino, and White adults aged ≥ 18 years residing in the Southern U.S. in 2018. Census tract-level social vulnerability data were obtained from the 2018 CDC Social Vulnerability Index (SVI). Rate and proportion ratios were used to determine the difference between the lowest quartile of SVI scores (Q1) and the highest quartile (Q4) by age group, transmission category, and region of residence and stratified by sex assigned at birth. Areas with the highest social vulnerability (Q4) had the highest rates of HIV diagnoses (Black: 56.5, Hispanic/Latino: 27.2, and White: 10.3). Those in Q4 also had the lowest percentages of adults linked to care (Black: 76.1%, Hispanic/Latino: 81.2%, and White: 77.8%), and the lowest percentages of adults with viral suppression (Black: 59.8%, Hispanic/Latino: 68.4%, and White: 65.7%). This ecological study found an association between social vulnerability, HIV diagnoses, and poorer care outcomes among Black/African American, Hispanic/Latino, and White adults. Tailoring interventions and improving access for persons residing in areas with the highest social vulnerability is necessary to reduce HIV transmission and improve health outcomes in the Southern U.S.