Evaluating Spatially Targeted HIV Interventions and Harm Reduction Services Among People Who Inject Drugs in a...

Area of Science:

• Epidemiology
• Public Health
• Mathematical Modeling

Background:

• People who inject drugs (PWID) in India face high HIV incidence.
• Current HIV and harm reduction service coverage for PWID is suboptimal.
• Novel service delivery points are needed to improve HIV prevention.

Purpose of the Study:

• To evaluate the effectiveness of spatially focused HIV interventions at drug injection venues.
• To model HIV transmission dynamics among PWID in New Delhi.
• To identify optimal strategies for scaling up harm reduction services.

Main Methods:

• Developed an individual-based dynamic HIV transmission model.
• Utilized data from a sociometric study of 2512 PWID in New Delhi.
• Simulated HIV incidence under various spatial targeting and service coverage scenarios.

Main Results:

• Significant decreases in predicted HIV incidence were observed when interventions were deployed at frequently visited injection venues.
• Full service coverage at the most-visited venue reduced incidence from 6.8 to 2.7 cases/100 person-years.
• Targeting 12 most-visited venues reduced incidence to 1.3 cases/100 person-years.
• Prioritizing venues by spatial clusters, rather than overall popularity, reached more individuals and had a slightly larger impact.

Conclusions:

• Spatially focused HIV interventions at high-frequency drug injection venues are effective in reducing HIV incidence among PWID.
• Strategic expansion of services at spatially distinct venues with minimal overlap maximizes intervention impact.
• Modeling provides a valuable tool for optimizing resource allocation in HIV prevention programs for PWID.