Identifying the Factors Associated With Spatial Clustering of Incident HIV Infection Cases in High-Prevalence...

Area of Science:

• Epidemiology
• Geospatial Analysis
• Public Health

Background:

• Incident HIV infection is a key epidemic indicator, especially in high-burden regions like Liangshan Yi Autonomous Prefecture, China, where prevalence exceeds 1% in four key counties.
• Identifying spatial clusters and drivers of recent HIV infections is crucial for targeted interventions, yet studies on incident HIV clustering drivers are limited, particularly in low-resource settings.

Purpose of the Study:

• To pinpoint spatial clusters of recent HIV infections within four key counties of Liangshan Yi Autonomous Prefecture.
• To investigate potential driving factors contributing to these recent HIV infection clusters.
• To inform the development of targeted intervention strategies for HIV prevention and control in the region.

Main Methods:

• Identified 246 recent HIV infection cases (4.42%) from 5555 newly diagnosed cases (Nov 2017-Jun 2018) using limiting antigen avidity assays or documented seroconversion.
• Analyzed spatial distribution of incident HIV cases using kernel density estimation.
• Employed spatial lag regression and Geodetector q-statistic to identify and quantify factors associated with clustering, including population density, HIV prevalence, elevation, urban proximity, and ART coverage.

Main Results:

• Significant spatial autocorrelation of recent HIV cases (Moran I=0.11; P<.01) was observed, with six spatial clusters identified near urban centers or major roads.
• Population density (β=0.59), HIV prevalence (β=0.02), distance to urban area (β=-3.10), SD of elevation (β=-0.15), and ART coverage (β=183.80) were significantly correlated with clustering.
• Population density and HIV prevalence showed the strongest interactive effect (q=0.69) in driving HIV clustering.

Conclusions:

• Incident HIV clustering in Liangshan is driven by urbanization factors (population density, urban proximity) and transportation accessibility, in addition to HIV prevalence.
• Higher antiretroviral therapy (ART) coverage was paradoxically associated with increased transmission, highlighting the need for integrated prevention strategies beyond ART expansion.
• A township-level geospatial approach is valuable for identifying transmission hotspots and tailoring interventions in global high-burden regions.