Characterizing Non-linear Effects of Hospitalization Duration on Antimicrobial Resistance in Respiratory Isolates: A Retrospective Analysis of a Prospective Nationwide Surveillance System.
Publisher DOI
PubMed ID
28559001
Abstract
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 of respiratory isolates retrospectively retrieved from patients hospitalized between 2008-2014 were compiled. Generalized additive models were used to illustrate resistance rates relative to hospitalization duration and to adjust for co-variables.
RESULTS
19,622 isolates of six relevant and predominant species were included. Resistance patterns for the predominant species showed a species and antibiotic resistance specific profile in function of hospitalization 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 five days of hospitalization 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 seven days of hospitalization 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 vs. late nosocomial) as suggested by current hospital-acquired pneumonia treatment guidelines. Duration of hospitalization rather appears to have a more complex and non-linear relationship with bacterial resistance in hospital-acquired pneumonia, also depending on host/environmental factors.
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 of respiratory isolates retrospectively retrieved from patients hospitalized between 2008-2014 were compiled. Generalized additive models were used to illustrate resistance rates relative to hospitalization duration and to adjust for co-variables.
RESULTS
19,622 isolates of six relevant and predominant species were included. Resistance patterns for the predominant species showed a species and antibiotic resistance specific profile in function of hospitalization 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 five days of hospitalization 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 seven days of hospitalization 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 vs. late nosocomial) as suggested by current hospital-acquired pneumonia treatment guidelines. Duration of hospitalization rather appears to have a more complex and non-linear relationship with bacterial resistance in hospital-acquired pneumonia, also depending on host/environmental factors.
Date Issued
2018-01
Publication Type
Article
Subjects
Antimicrobial Resistance Nosocomial Pneumonia Respiratory Tract
Language(s)
en
Author(s)
Additional Credits
Journal
Clinical microbiology and infection
Publisher
Elsevier
ISSN
1198-743X
Access(Rights)
restricted