Low incidence of subsequent bacteraemia or fungaemia after removal of a colonized intravascular catheter tip.

OBJECTIVES: We determined the frequency of subsequent bloodstream infection more than 2 days after removal of a catheter with positive tip cultures. METHODS: We conducted a nationwide, observational study on intravascular catheter (IVC) tip cultures in Switzerland from 2008 to 2015 using data from the Swiss Antibiotic Resistance Surveillance System (ANRESIS). An IVC tip culture was included in the analysis if at least one microorganism could be cultivated from it. We excluded all data from patients with concurrent bacteraemia with the same microorganism identified 7 days before to 2 days after IVC removal. Subsequent bloodstream infection was defined as isolating (from blood cultures performed more than 2 days up to 7 days after catheter removal) the same microorganism as the one recovered from the IVC. Data on antibiotic therapy were not available in this surveillance study. RESULTS: Over the 8-year period, 15 033 positive IVC tip cultures were identified. Our study population comprised 12 513 episodes of positive IVC tip cultures without concurrent bacteraemia. The frequency of sBSI was 1.8% (n = 219). Subsequent bloodstream infections were more frequently detected after identification of C. albicans (10/113, 8.8%), S. marcescens (9/169, 5.3%), and S. aureus (30/623, 4.8%) on a catheter tip. CONCLUSIONS: A very low incidence of subsequent bloodstream infection was observed if a microorganism was identified on a removed IVC tip without concurrent bacteraemia. The risk of subsequent bloodstream infection increased if C. albicans, S. aureus, or S. marcescens were identified in this context.

Characterizing non-linear effects of hospitalisation duration on antimicrobial resistance in respiratory isolates: an analysis of a prospective nationwide surveillance system.

OBJECTIVES: Our objective was to systematically study the influence of length of hospital stay on bacterial resistance in relevant respiratory tract isolates. METHODS: Using prospective epidemiological data from the National Swiss Antibiotic Resistance Surveillance System, susceptibility testing results for respiratory isolates retrospectively retrieved from patients hospitalised between 2008 and 2014 were compiled. Generalized additive models were used to illustrate resistance rates relative to hospitalisation duration and to adjust for co-variables. RESULTS: In all, 19 622 isolates of six relevant and predominant species were included. Resistance patterns for the predominant species showed a species-specific and antibiotic-resistance-specific profile in function of hospitalisation duration. The oxacillin resistance profile in Staphylococcus aureus isolates was constantly increasing (monophasic). The pattern of resistance to cefepime in Pseudomonas aeruginosa was biphasic with a decreasing resistance rate for the first 5 days of hospitalisation and an increase for days 6-30. A different biphasic pattern occurred in Escherichia coli regarding amoxicillin-clavulanic acid resistance: odds/day increased for the first 7 days of hospitalisation and then remained stable for days 8-30. In the adjusted models epidemiological characteristics such as age, ward type, hospital type and linguistic region were identified as relevant co-variables for the resistance rates. The contribution of these confounders was specific to the individual species/antibiotic resistance models. CONCLUSIONS: Resistance rates do not follow a dichotomic pattern (early versus late nosocomial) as suggested by current hospital-acquired pneumonia treatment guidelines. Duration of hospitalisation rather appears to have a more complex and non-linear relationship with bacterial resistance in hospital-acquired pneumonia, also depending on host and environmental factors.

Effectiveness of meticillin-resistant Staphylococcus aureus decolonization in long-term haemodialysis patients: a systematic review and meta-analysis.

BACKGROUND: Chronic haemodialysis patients are a high-risk population for meticillin-resistant Staphylococcus aureus (MRSA) colonization, which is a precursor of infection. AIM: To summarize the effect of nasal (± whole-body wash) MRSA decolonization in haemodialysis patients by means of a systematic review and meta-analysis. METHODS: We identified eligible studies using Medline, Embase, the Cochrane database, clinicaltrials.org, and conference abstracts investigating the success of MRSA decolonization in haemodialysis patients. For the statistical analysis, we used Stata 13 to express study-specific proportions with 95% confidence intervals. A likelihood ratio test was used to assess inter-study heterogeneity. FINDINGS: Six published prospective cohort studies and one study described in a conference abstract met our inclusion criteria. From 1150 haemodialysis patients enrolled in these studies, MRSA was isolated from nasal swabs of 147 (12.8%) patients. Six of the trials used mupirocin nasal ointment and combined it with chlorhexidine body washes for decolonization. The most widely used protocol was a five-day course of mupirocin nasal ointment application three times a day, and chlorhexidine body wash once daily. The pooled success rate of decolonization was 0.88 (95% confidence interval: 0.75-0.95). A likelihood ratio test of the fixed versus the random-effects model showed significant inter-study heterogeneity (P = 0.047). Four of seven studies determined subsequent MRSA infections in 94 carriers overall, two (2%) of which experienced infection. CONCLUSION: The use of mupirocin together with whole-body decolonization is highly effective in eradicating MRSA carriage in haemodialysis patients. The current literature, however, is characterized by a lack of comparative effectiveness studies for this intervention.