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Published on: February 23, 2014
Risk factors for methicillin-resistant Staphylococcus aureus in patients with community-onset and hospital-onset
1University of California, San Francisco, Department of Internal Medicine, USA. darcy.wooten@ucsf.edu
Objectives:
The risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia have not been fully characterized and are likely to be different depending on whether infection is acquired in the community or the hospital.
Methods:
We conducted a case-control study of 619 adults hospitalized between 2005 and 2010 with either MRSA or methicillin-sensitive S. aureus (MSSA) pneumonia. Patients with a respiratory culture within 48 h of hospitalization had community-onset pneumonia whereas patients with a culture collected after this time point had hospital-onset pneumonia.
Results:
Among patients with community-onset disease, the risk for MRSA was increased by tobacco use (OR 2.31, CI 1.23-4.31), chronic obstructive pulmonary disease (OR 3.76, CI 1.74-8.08), and recent antibiotic exposure (OR 4.87, CI 2.35-10.1) in multivariate analysis while patients with hospital-onset disease had an increased MRSA risk with tobacco use (OR 2.66, CI 1.38-5.14), illicit drug use (OR 3.52, CI 2.21-5.59), and recent antibiotic exposure (OR 2.04, CI 3.54-13.01). Hospitalization within the prior three months was associated with decreased risk (OR 0.64, CI 0.46-0.89) in multivariate analysis.
Conclusions:
This study suggests there are common and distinct risk factors for MRSA pneumonia based on location of onset. The decreased risk for MRSA pneumonia associated with recent hospitalization is unexpected and warrants further investigation.
Summary:
This case-control study showed that there are common and distinct risk factors associated with MRSA pneumonia depending on whether the infection onset is in the hospital or in the community. Recent hospitalization was unexpectedly shown to be associated with decreased risk for MRSA pneumonia and warrants further investigation.
Insights
Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia differ by community or hospital onset. Tobacco use, COPD, and antibiotic exposure are key risks, while recent hospitalization unexpectedly decreased MRSA pneumonia risk.
Area of Science:
- Infectious Diseases
- Pulmonary Medicine
- Critical Care Medicine
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia risk factors are not fully understood.
- Community-acquired and hospital-acquired pneumonia may have distinct risk profiles.
- Characterizing these factors is crucial for effective prevention and treatment strategies.
Purpose of the Study:
- To identify and compare risk factors for MRSA pneumonia based on the site of infection onset (community vs. hospital).
- To investigate the influence of various patient characteristics and exposures on MRSA pneumonia development.
Main Methods:
- A case-control study involving 619 adult patients hospitalized between 2005 and 2010.
- Patients were categorized by MRSA or methicillin-sensitive S. aureus (MSSA) pneumonia.
- Pneumonia onset was classified as community-onset (culture within 48 hours of admission) or hospital-onset (culture after 48 hours).
Main Results:
- For community-onset MRSA pneumonia, risk factors included tobacco use (OR 2.31), COPD (OR 3.76), and recent antibiotic exposure (OR 4.87).
- For hospital-onset MRSA pneumonia, risk factors included tobacco use (OR 2.66), illicit drug use (OR 3.52), and recent antibiotic exposure (OR 2.04).
- Recent hospitalization (within 3 months) was associated with a decreased risk of MRSA pneumonia (OR 0.64).
Conclusions:
- Common and distinct risk factors for MRSA pneumonia exist depending on community or hospital onset.
- Tobacco use, COPD, illicit drug use, and recent antibiotic exposure are significant risk factors.
- The finding that recent hospitalization decreases MRSA pneumonia risk is unexpected and requires further research.
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