Injection Indicator Diseases: Bacterial and Viral Infections That Indicate Injection Drug Use in a Community Hospital Setting

Certain infections can be strongly suggestive of injection drug use and thereby used as markers of such behavior. A retrospective cohort study of patients admitted between September 2003 and May 2007 with a history of prior and/or current substance use was undertaken to determine whether findings in our inner city population differed from existing data. The 1799 patients had 2531 hospital admissions with evidence of cocaine and/or heroin use. The average age was 45 years, with an age range of 16-79 years old. Cocaine-only use was reported twice as frequently (n=906, 36%) as heroin-only use (n=456, 18%) and 190 (69%) of the heroin-only users injected whereas 96 (19%) of the cocaine-only users injected. Of the 882 injection drug users, 597 (68%) had one or more viral diseases, whereas 285 (32%) had none; 491 (55%) had Hepatitis C, 102 (11%) had Hepatitis B, and 304 (34%) had HIV. Suppurative back infections were found in 22 patients, 41 had endocarditis with or without septic emboli, 44 had deep abscesses not related to local injection or spinal infection, 12 had septic arthritis, and 144 had generalized bacteremia/ sepsis. In the setting of an inner city community hospital, the presence of injection drug use appears to represent the highest risk of associated viral and bacterial infections. These infections could be denoted as “Injection Indicator Diseases”.