Nearly all participants of the study were men who injected drugs twice a day on average (representative picture). Credit: Krisanapong Detraphiphat/ Moment/ Getty Images

Implementing strategies at select sites could dramatically reduce HIV transmission among people who inject drugs (PWID) in New Delhi1. Study data show that interventions at just one location could reduce transmission in five other locations.

The findings may help to devise ways to efficiently interrupt HIV transmission among PWID, says an international research team.

Globally, HIV epidemics hit PWID hard, yet HIV transmission in these communities is still poorly understood, particularly in low- and middle-income countries.

Using deep learning methods and social network analysis, scientists analysed 2,512 injection partners and 181 injection venues spread over 20 km in New Delhi. They found that nearly all participants were men who injected drugs twice a day on average. Of these, 51% reported sharing drug paraphernalia in the six months before the study.

The team, which included researchers at the YR Gaitonde Centre for AIDS Research and Education in Chennai, found that the most commonly injected drugs were buprenorphine and heroin. HIV prevalence at baseline was 37%. Among participants who tested positive for HIV antibodies, 8% had HIV RNA less than the lower limit of quantification, and 6% self-reported ever taking antiretroviral therapy.

Of 159 people with HIV who visited 158 venues, 74% were directly connected to at least one participant with a detectable viral load, and all were within one degree of separation from a participant with detectable HIV.

The researchers say their findings highlight how network analysis and deep learning can pinpoint optimal points of intervention to interrupt HIV transmission among PWID.