Factors associated with skin and soft tissue infections among people who inject drugs in the United Kingdom: A comparative examination of data from two surveys

Background: People who inject drugs (PWID) are at high risk of injection-related skin and soft tissue infections (SSTI). If not treated promptly, these can lead to serious health complications, which are a considerable healthcare burden. Data from two community surveys, with different approaches, were used to assess SSTI prevalence and associated factors among PWID to inform intervention implementation. Methods: Data were analysed from two surveys, a national surveillance survey (n=2,874; 2017-18) of infections among PWID in the United Kingdom (UK) and an in-depth survey (n=455; 2018-19) of SSTI among PWID based in London, UK. Multivariable logistic regression models were constructed to ascertain the factors associated with self-reported SSTI. Results: High prevalence of SSTI were reported in both samples: 52 % of participants from the national surveillance survey reported having SSTI within the preceding 12 months and 65 % of the London sample reported a lifetime history of SSTI. The factors associated with SSTI in both surveys were similar, including older age; number of years injecting; number of attempts required to inject into the vein; injecting into the hands, feet, groin or neck and re-using or sharing needles/syringes. Conclusions: The number of PWID reporting SSTI in the UK is concerningly high. The two surveys used different recruitment approaches but found similar associations. We provide strong evidence of a relationship between venous access difficulty and SSTI. To stem the increase of SSTI and related complications in the UK, it is crucial that interventions attend to the underlying causes of venous damage among PWID.