Bakterielle hud- og bløtvevsinfeksjoner hos injiserende stoffmisbrukere i sykehus. : Forekomst, mikrobiologi og behandling.

Abstract

Skin and soft tissue infections (SSTIs) cause significant morbidity among intravenous drug users (IVDUs). Information about special features of SSTIs in IVDUs is essential for treatment.

We performed a retrospective cross-sectional study in a Norwegian university hospital. Using the ICD-10-classification, we selected admissions for abscess, cellulitis and erysipelas from two subsequent years and excluded non-IVDUs. From the patient charts we collected information about demographic data, anatomical localisations, microbiological findings and treatment.

192 admissions of 144 IVDUs were selected. IVDUs utilized 1/5 of hospitalisation days for SSTIs and 1/3 for abscesses. Most SSTIs were localized in the lower extremities and 15% had coexisting bacterial infections other than SSTIs. In abscesses, streptococci (42,9%), staphylococci (40,0%), gram-negative rods (8,6%) and anaerobic bacteria (6,4%) were the most commonly isolated strains. 1/4 had mixed cultures. In erysipelas and cellulitis, staphylococci (42,3%) and streptococci (19,2%) dominated. We found two strains of MRSA in one patient. Surprisingly, 8% of staphylococci were clindamycin resistant and clindamycin was commonly prescribed, raising concern about selection of resistant strains. 85% received effective antibiotics. There was compliance to guidelines for empirical antimicrobial therapy in 2/3 of cases, with most patients receiving dicloxacillin/cloxacillin or penicillin. Among non-compliant cases, a larger proportion of patients received ineffective and/or too broad-spectrum antibiotics. For abscesses, the use of antibiotics is generally controversial. Today’s guidelines for empirical therapy cover the most common pathogens in IVDUs. Our material was limited regarding erysipelas and cellulitis, but findings suggest that dicloxacillin/cloxacillin may be the better empirical treatment for IVDUs. In general, antimicrobial therapy was adjusted according to microbiological findings in only 50% of the cases in our study.