Epidemiology of Injection-Related Bacterial and Fungal Infections in PWID
Overview
This systematic review and meta-analysis synthesized data from 87 studies across 25 countries to estimate the prevalence and incidence of bacterial and fungal infections among people who inject drugs (PWID). Skin and soft-tissue infections were the most common, with lifetime prevalence reaching 47%, while severe infections like endocarditis and sepsis had lower but significant prevalence rates.
Background
Injection-related infections are a frequent and serious complication of injecting drug use, ranging from localized skin and soft tissue infections to severe systemic infections such as endocarditis and bloodstream infections. These infections result from the introduction of bacteria or fungi during injection and can lead to hospitalization, disability, and premature mortality. Despite their clinical importance, comprehensive epidemiological data on these infections among PWID have been limited. This review addresses this gap by providing updated pooled estimates of infection prevalence and incidence.
Data Highlights
Infection Type
Prevalence Period
Prevalence (%)
95% Confidence Interval
Number of Studies
Skin and Soft-Tissue Infections
Past month
13
9–19
11
Skin and Soft-Tissue Infections
Past 3–12 months
30
23–37
23
Skin and Soft-Tissue Infections
Lifetime
47
29–66
7
Endocarditis
Past month
2
1–3
4
Endocarditis
Past 3–12 months
2
2–3
5
Endocarditis
Lifetime
6
3–10
8
Sepsis and/or Bloodstream Infection
Past month
1
1–2
2
Sepsis and/or Bloodstream Infection
Past 3–12 months
7
4–13
3
Sepsis and/or Bloodstream Infection
Lifetime
8
3–19
5
Key Findings
Skin and soft-tissue infections are highly prevalent among PWID, affecting nearly half over a lifetime.
Endocarditis prevalence remains relatively low but clinically significant, with a lifetime prevalence of 6%.
Sepsis and bloodstream infections occur less frequently but carry substantial morbidity, with lifetime prevalence up to 8%.
Data were drawn from 87 studies spanning 25 countries, including low- and middle-income settings, enhancing generalizability.
Hospitalizations for injection-related infections are increasing, imposing significant healthcare costs and individual morbidity.
Clinical Implications
Clinicians should maintain a high index of suspicion for injection-related infections in PWID, particularly skin and soft tissue infections which are common. Early recognition and treatment are critical to prevent progression to severe systemic infections such as endocarditis and sepsis. Harm reduction strategies and targeted interventions are urgently needed to reduce infection incidence and associated healthcare burden.
Conclusion
Injection-related bacterial and fungal infections represent a substantial health burden among people who inject drugs, with skin and soft tissue infections being the most common. Comprehensive prevention and management strategies are essential to mitigate morbidity and healthcare costs.
