Injecting drug use related bacterial infections requiring hospital care in Gothenburg 2008-2011

Abstract

Master thesis, Programme in Medicine. TITLE: Injecting drug use related bacterial infections requiring hospital care in Gothenburg 2008-2011. AUTHOR: Olle Andersson. Background 14 million people world-wide is estimated to be active injecting drug users. In Gothenburg, this number is at least 922. Injecting drug users (IDUs) have higher incidence of infectious endocarditis (IE) (particulary right-sided) and skin and soft tissue infections (SSTIs) compared to the general population. Many of the risk factors for acquiring these diseases are hygienic, such as the usage of unsterile needles and syringes and needle sharing. Aim To estimate the incidence and describe the clinical features of IDUs requiring hospital care in Gothenburg, Sweden for bacterial infections, and to document the injection habits of IDUs in Gothenburg. Materials and methods A retrospective study of the Swedish quality register for infectious diseases and hospital records from several departments at the Sahlgrenska university hospital. 171 hospital stays treated for IE and 3468 hospital stays treated for 15 different SSTIs between 2008-2011 were reviewed. When IDUs were found in these groups, additional data from their hospital stays were recorded and analysed for differences between groups. IDU patients at the department of infectious diseases in Gothenburg were interviewed between February and April of 2014 on their injection habits.

Results IE incidence was 3.45 for IDUs vs. 0.08 / 1000 person-years for the general population and SSTI incidence requiring hospital care was 19.25 for IDUs vs 1.67 / 1000 person-years for the general population. IDUs were younger than controls and males dominated in the SSTI IDU group compared to the non-IDU group (p<0.05), but not in the IE groups. S.aureus was the most frequent cause of infection. Discussion / conclusions IDUss had high incidence of hospital care for bacterial infections, most commonly caused by S.aureus, and were dominated by men in their thirties. Contrary to previous studies, our IDU IE patients predominantly had a left-sided IE. None of the interviewees took hygienically precautions before injectional drug injections, all reused needles and all had been sharing needles.