Evolving epidemiology of injecting drug use‐associated infective endocarditis: A regional centre experience

and Aims Injecting drug use ( IDU ) is a major risk factor for infective endocarditis ( IE ). An understanding of the epidemiology of IE and IDU is vital for delivery of health care for this disease. Our aim was to examine the rates of IDU ‐associated IE ( IDU ‐ IE ) in a single centre over the last 12 years. Design and Methods Retrospective analysis of two cohorts of consecutive patients ( n  = 226) admitted with IE from 2002 to 2013. Numbers of cases and rates of IE were compared between two cohorts (2002–2006 and 2009–2013). Rate ratios were calculated using P oisson distributions. P oisson regression was used to examine relationship over time. Results One hundred thirty cases of endocarditis were seen in the first observation period (6 IDU ‐ IE ) and 96 in the second observation period (15 IDU ‐ IE ). The estimated incidence rate of IE had fallen from 10.1 to 6.45 per 100 000 person‐years [rate ratio 0.64, 95% confidence interval ( CI ) 0.48, 0.85]. In contrast, the estimated incidence rate of IDU ‐ E has risen from 0.48 to 0.79 per 100 000 person‐years (rate ratio 1.65, 95% CI 0.59, 4.57). Incidence rate regression suggests that the number of IDU ‐ IE cases is expected to increase by a factor of 1.25 (95% CI 1.09–1.44) for each increase of 1 year. Discussion and Conclusions Over the last decade, there has been a decrease in incidence rate and total number of cases of IE but a rise in rate and number of cases of IDU ‐ IE . This may indicate increasing IDU or increased rates of endocarditis in intravenous drug users in this region. This finding may inform health‐care planning in the area. [Tung MKY, Light M, Giri R, Lane S, Appelbe A, Harvey C, Athan E. Evolving epidemiology of injecting drug use‐associated infective endocarditis: A regional centre experience. Drug Alcohol Rev 2015;34:412–417]