Background: In light of the shift in bloodstream infections (BSIs) toward gram-negative bacteria described in Europe, we wanted to describe the epidemiology of BSIs comparing the frequency of selected pathogens in both community (CHs) and university hospitals (UHs).
Methods: Data on BSI from 2008 to 2014 were obtained from the representative Swiss antibiotic resistance surveillance system ANRESIS. Using descriptive statistics we compared pathogen prevalences over time in all participating acute care hospitals (n=26). We performed a subanalysis for community-acquired (CA) and hospital-acquired (HA) BSIs in CHs and UHs.
Results: We analyzed a total of 42'802 BSI episodes. The annual total of reported episodes increased over time (2008: 5'754, 2014: 6'934). The most common etiologies were E. coli (12'103; 28.3%), S. aureus (5'317; 12.4%) and polymicrobial BSI (4'893; 11.4%). The proportion of E.coli increased marginally from 27.5% (1'582) in 2008 to 29.6% (1'978) in 2014 (p=0.04). E. coli was more common in women (36.4% vs 22.5%, p<0.001) and older people (34.1% in >65 years vs 18.2% in 15-45 years), whereas S. aureus predominated among younger patients (21.3% in 2-15 years vs 11.9% >65 years). Compared to southwestern (SW) Switzerland, the northeastern part (NE) had more polymicrobial (12.8% vs 9.3%, p<0.001), Coagulase-negative Staphylococcal [CoNS] (11.9% vs 4.7%, p<0.001) and fungal (2.0% vs 0.8%, p<0.001) BSIs. Regarding departmental differences, polymicrobial BSI dominated in ICUs (18.6%), E. coli in outpatient (39.3%) and internal medicine-departments (25.4%).
According to hospital type, E. coli was more commonly reported from CHs (34.3% vs 22.7%, p<0.001). 50% (21'308) of episodes were CA, with E. coli again being more common in CHs (41.0% vs 32.4%, p<0.001), in contrast, polymicrobial (9.9% vs 5.6%, p<0.001) and CoNS (6.6% vs 3.4%, p<0.001) were more prevalent in UHs. We observed divergent trends in CA BSI among the two hospital types (cf. fig. 1 for CA-E.coli). Similar patterns/trends were observed in the HA subset of BSI.
Conclusion: E. coli's role as predominant pathogen in BSI in Switzerland has recently become more pronounced. There are distinct patterns and trends in CHs and UHs potentially influencing empiric antibiotic treatment.
A. Atkinson, None
A. Kronenberg, None