HIV / STI
Geospatial injection venue attendance dynamics and HIV incidence among people who inject drugs in New Delhi, India from 2017-2025 Griffin Bell* Griffin Bell Bell Bell Bell Bell Bell Bell Bell Bell Bell Johns Hopkins University
HIV incidence among people who inject drugs (PWID) in New Delhi, India is among the highest globally. The SARS-CoV-2 pandemic disrupted harm-reduction services and forced relocations, but its effect on HIV transmission is unknown.
To examine spatiotemporal HIV incidence trends, we established a longitudinal cohort of New Delhi PWID. Recruitment, via injection partner referral, occurred in two waves: 2512 participants pre-pandemic (2017–2020) and 988 post-pandemic (2022–2025). Participants underwent rapid HIV testing and completed a behavioral survey at enrollment and up to 10 semi-annual visits. We compared HIV incidence, estimated through Poisson models with generalized estimating equations, over time and across geographic groupings of injection venues, termed “Areas.” Analyses accounting for differential loss to follow-up and death are in progress.
Incidence declined from a pre-pandemic rate of 21 (95% CI: 18-24) cases per 100 person-years (100PY) to a post-pandemic rate of 5 (3-6) per 100PY. Pre-pandemic incidence in a group of venues, “Area 8,” attended by 53% of the cohort was 39 (33-46) per 100PY overall, and 78 (57-107) per 100PY among those reporting needle-sharing. Post-pandemic, Area 8 experienced reduced attendance (53% to 9%), increased saturation of susceptible individuals (40% HIV prevalence pre-pandemic to 65-70% after 2021), and a reduction in incidence to 17 (7-40) per 100PY. Pre-pandemic incidence outside Area 8 was significantly lower at 8 (6-11) per 100PY, declining to 4 (3-6) per 100PY post-pandemic. Surprisingly, needle-sharing at baseline was higher post-pandemic compared to pre-pandemic (54% vs 47%).
HIV acquisition risk depends on individual behaviors, injection networks, and injection venue contexts. Reduced transmission post-pandemic may largely reflect reduced attendance, saturation of susceptible individuals, and behavioral changes at high-incidence venues. High levels of needle-sharing post-pandemic highlight ongoing vulnerability.