Injection drug use (IDU) puts people at risk for acquiring and transmitting HIV infection. An increase in IDU, attributed to the opioid epidemic, has placed new populations at risk for HIV. Analysis of geographic differences in HIV diagnoses, linkage to care, and viral suppression is important to identify gaps in HIV care for people who inject drugs (PWID).

Lyss et al. (2021) described differences in U.S. rural-urban trends in HIV infection among PWID between 2010 to 2014 and 2014 to 2018 [1]. Between 2010 and 2014, there was a significant overall decline in HIV diagnoses among PWID across all categories of metropolitan counties and micropolitan areas [1]. However, from 2014 to 2018, there was an increase in HIV diagnoses among PWID, particularly in small metro counties [1]. These recent changes across the rural-urban continuum have reshaped historical patterns, resulting in an increase in the proportion of HIV diagnoses among PWID that occurred outside large central metro counties. Exploring these trends is vital for targeting public health interventions more effectively and improving HIV prevention and treatment for PWID.

We describe regional and rural-urban trends in HIV diagnoses attributed to IDU and HIV care outcomes for PWID with HIV diagnosed from 2016 to 2022, using CDC’s National HIV Surveillance System (NHSS) data. Findings from this analysis will enhance our understanding of geographic trends in HIV diagnoses and HIV care outcomes among PWID and will help inform efforts to improve HIV care delivery for PWID.

Data reported to NHSS through December 2023 were used to determine rural-urban differences and regional trends in diagnoses and care outcomes among adults and adolescents (aged 13 years or older) with infection attributed to IDU from 2016 to 2022. Diagnoses, linkage to care within one month of diagnosis, and viral suppression within six months after diagnosis were examined in 40 jurisdictions with complete reporting of CD4 and viral load test results from 2016 to 2022 (Figure 1). To examine regional trends, data were categorized by U.S. Census Divisions as follows: the Northeast, covering New England (CT, MA, ME, NH, RI) and the Mid Atlantic (NY); the Midwest, including East North Central (IL, IN, MI, WI) and West North Central (IA, MN, MO, NE, ND, SD); the South, comprising South Atlantic (DC, DE, FL, GA, MD, NC, SC, VA, WV), East South Central (AL, MS, TN), and West South Central (LA, TX); and the West, encompassing the Mountain (CO, MT, NM, UT, WY) and Pacific (AK, CA, HI, OR, WA) regions.

Linkage to HIV care within one month of diagnosis was defined as having at least one CD4 or viral load test result with a specimen collection date within one month after HIV diagnosis. Viral suppression within six months of diagnosis was defined as having a viral load result <200 copies/mL with a specimen collection date within six months after diagnosis. Statistical adjustment using multiple imputation techniques were applied to account for cases with missing transmission category [2].

Findings were stratified by rural or urban residence at diagnosis. US Department of Agriculture Economic Research Service Rural-Urban Continuum Codes (RUCC) were used to define rural or urban residence at the county level [3]. RUCC defines metropolitan counties by the population size of their metro area, and nonmetropolitan counties by their degree of urbanization and adjacency to a metropolitan area. In this analysis, metro counties (RUCC 1 to 3) were referred to as “urban” and nonmetro counties (RUCC 4 to 9) as “rural”.

Urban and rural counties were further categorized based on the population size of the metro area within them. Large urban counties contained metropolitan areas with more than 1 million people (RUCC = 1). Medium urban counties had metropolitan areas with populations ranging from 250,000 to 1 million (RUCC = 2). Small urban counties included metropolitan areas with less than 250,000 people (RUCC = 3). Large rural counties had small urban centers with populations of 20,000 or more (RUCC = 4 and 5), medium rural counties had populations ranging from 2,500 to 19,999 (RUCC = 6 and 7), and small rural counties had populations with fewer than 2,500 people (RUCC = 8 and 9)(Figure 1).

Trends in diagnoses, linkage to HIV care, and viral suppression from 2016 to 2022 were assessed by calculating the estimated annual percentage change (EAPC). EAPCs and their 95% confidence intervals (CIs) were determined using Poisson regression. An EAPC was considered statistically significant if its 95% CI did not include zero. The year 2020 was excluded from the EAPC analysis due to the impact of the COVID-19 pandemic on HIV testing, care, and potential disruptions in reporting processes [4].

In large rural counties, HIV diagnoses attributed to IDU among adolescents and adults increased from 98 in 2016 to 126 in 2022 (EAPC: 4.86%, 95% CI: 0.92, 8.96) and remained stable in small and medium rural counties during the same period. HIV diagnoses attributed to IDU also increased from 193 to 265 (EAPC: 5.67%, 95% CI: 2.62, 8.81) in small urban counties and from 593 to 756 (EAPC: 4.95%, 95% CI: 3.19, 6.75) in medium urban counties (Table 1). In contrast, diagnoses declined in large urban counties, from 2,084 in 2016 to 1,797 in 2022 (EAPC: −2.46%, 95% CI: −3.48, −1.43).

Linkage to HIV care within one month of diagnosis remained stable in all rural counties and in small and medium urban counties from 2016 to 2022 but increased in large urban counties, from 72.8% to 79.3% (EAPC: 1.21%, 95% CI: 0.66, 1.76) (Table 1). Viral suppression within six months also remained stable in all rural counties, small urban counties, and medium urban counties, while increasing in large urban counties from 50.4% to 58.4% (EAPC: 2.00%, 95% CI: 1.17, 2.84) (Table 1).

Regionally, HIV diagnoses attributed to IDU increased in rural counties of the West North Central division in the Midwest and the East South Central division in the South, from 23 to 39 (EAPC: 8.21%, 95% CI 0.50, 16.51) and from 16 to 46 (EAPC: 16.15%, 95% CI 7.12, 25.94), respectively (Table 2). Urban counties in these divisions also saw an increase in IDU-related diagnoses, from 100 to 127 (EAPC: 5.50%, 95% CI: 1.79, 9.35) in West North Central and from 88 to 177 (EAPC: 12.28%, 95% CI: 8.11, 16.60) in East South Central (Table 2). In contrast, urban counties in the New England, Mid Atlantic, and Mountain divisions experienced a decline in HIV diagnoses attributed to IDU, decreasing from 179 to 121 (EAPC: −6.70%, 95% CI: −9.50, −3.81), 278 to 203 (EAPC: −4.64%, 95% CI: −4.64, −1.61), and 130 to 70 (EAPC: −6.31%, 95% CI: −9.95, −2.52), respectively (Table 2).

From 2016 to 2022, linkage to HIV care within one month of diagnosis increased in urban counties in the West South Central and Pacific divisions, from 70.0% to 79.2% (EAPC: 1.50%, 95% CI: 0.24, 2.77) and from 73.5% to 80.5% (EAPC: 1.63%, 95% CI: 0.74, 2.53), respectively (Table 2). Viral suppression within six months of diagnosis increased in urban counties in the New England, East North Central, and South Atlantic divisions, from 57.6% to 66.0% (EAPC: 2.96%, 95% CI: 0.59, 5.38), 47.7% to 61.6% (EAPC: 3.44%, 95% CI: 0.91, 3.42), and 46.0% to 54.8% (EAPC: 1.94%, 95% CI: 0.48, 3.42), respectively (Table 2). In contrast, linkage to care and viral suppression in rural counties across nearly all U.S. census divisions did not experience a significant annual percent change and remained stable, except in the West South Central division, where viral suppression increased from 39.3% to 61.6% (EAPC: 5.69%, 95% CI: 0.09, 11.61) (Table 2).

This analysis highlights significant trends in HIV diagnoses attributed to IDU across the United States from 2016 to 2022. There was an increase in IDU-related HIV diagnoses in large rural, small urban, and medium urban counties, and a decline in large urban counties. Regionally, the West North Central and East South Central divisions saw significant increases in rural and urban areas, while there was a decline in diagnoses in urban areas of the New England, Mid Atlantic, and Mountain divisions.

Various factors could contribute to the increase in HIV diagnoses attributed to IDU in rural areas, including a lack of infrastructure and resources to prevent and treat HIV, as well as HIV- and substance use-related stigma (4). The current opioid epidemic experienced in the United States has significantly increased opioid-related overdose deaths and the number of individuals injecting opioids, especially in rural areas [5]. Innovative strategies are needed to reach individuals in rural areas, especially those experiencing multiple layers of stigma due to their HIV status and drug use. The decrease in diagnoses in large urban areas could be an indicator of reduced transmission or it could be driven by continued low testing rates after the pandemic in these areas.

While linkage to care and viral suppression increased in large urban areas, no significant improvements were observed in rural and small and medium urban jurisdictions. Regionally, some divisions saw urban improvements, but largely no improvements in rural areas. Rural county residents experience higher rates of poverty, less access to healthcare and transportation, and are less likely to have health insurance [6]. These factors pose major barriers for those seeking care after receiving a HIV diagnosis. Many rural counties lack harm reduction services and drug treatment providers, including access to medications for opioid use disorder, which are critical for engaging people who use drugs to prevent the spread of infectious diseases and educate them on the impacts and consequences of drug use [7]. Additionally, many rural communities lack healthcare providers specializing in HIV care or substance use disorders [7]. Due to the low availability and lack of funding for these services, individuals in need of care are forced to travel long distances for HIV-related care, including prevention services or treatment following diagnosis, leading to increases in diagnoses and decreases in linkage to care and viral suppression. Therefore, lack of transportation is a major barrier to obtaining preventative care and treatment services [5]. Due to these access barriers, PWID in rural areas experience a higher risk of HIV infection and other drug-use associated consequences [5].

Individuals with diagnosed HIV attributed to IDU experience multifaceted impacts of stigma. They are at higher risk of encountering both internalized and perceived stigma from their HIV status and drug use, and some may also face additional stigma related to factors such as race/ethnicity or sex [8]. Those with multiple stigmatizing characteristics often suffer more frequent negative encounters, which are associated with poorer health outcomes [8]. PWID residing in rural counties often experience stigma in healthcare settings, affecting their healthcare choices. Limited healthcare options in these areas can make it difficult to find non-stigmatizing care, which may reduce their willingness to discuss risky behaviors or seek treatment [8, 9].

Limitations of this analysis included that data were restricted to 40 jurisdictions with complete reporting of HIV-related laboratory data to CDC during the period analyzed; excluded jurisdictions consisted of 643 counties, 65.9% of which would be classified as rural [3]. Additionally, the rural-urban classification was at the county level, the smallest geographic unit available in NHSS data during the analysis period. County-level definitions of rural-urban may mask variations within counties, especially in areas on the fringe of metropolitan regions. Census tract-level rural-urban definitions should be considered in future analysis to enhance accuracy. The absence of comprehensive data on the total population of PWID prevented adjustments in the EAPC for population growth among PWID, thus limiting our ability to standardize trend data by PWID population size. Lastly, data from 2020 were excluded from the EAPC calculations due to significant disruptions in HIV testing services during the COVID-19 pandemic, which likely resulted in the underreporting of diagnoses to NHSS.

These findings highlight the importance of implementing and expanding innovative methods to reach and prioritize PWID in rural and small to medium urban areas for HIV prevention and treatment services, particularly in the East South Central and West North Central divisions. This could include the implementation of telemedicine services for HIV prevention and care provided by a culturally competent and trained healthcare workforce. Expanding telemedicine to provide services like pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), and linkage to care will positively impact rural residents by addressing transportation barriers, enabling HIV-related care from home, and minimizing access challenges by building the medical workforce’s capacity to deliver and promote PrEP adherence [10]. A review of multiple telemedicine applications in rural populations showed increased acceptability, satisfaction, and convenience, lower direct and indirect costs, and improved access to care [11]. Overall, removing barriers to linkage to care and viral suppression among all persons with diagnosed HIV attributed to IDU, with a particular focus on barriers experienced by those residing in rural or smaller urban communities, could improve outcomes.