nosocomial infection
Summary
A nosocomial or healthcare-associated infection is one acquired in a hospital or healthcare setting, conventionally defined as arising more than forty-eight hours after admission. The commonest are urinary catheter-associated infection, surgical site infection, pneumonia, and bloodstream infection.
Detail
Site predicts organism, and the associations are heavily examined. Catheter-associated urinary tract infection is most often Escherichia coli, then Proteus and Candida. Central line-associated bloodstream infection is dominated by coagulase-negative staphylococci, especially Staphylococcus epidermidis, which adheres via biofilm-forming glycocalyx, then S. aureus and Candida. Ventilator-associated pneumonia is caused by Pseudomonas aeruginosa, Staphylococcus aureus including MRSA, Klebsiella, Acinetobacter, and Enterobacter. Surgical site infection is usually S. aureus. Antibiotic-associated diarrhoea and pseudomembranous colitis are caused by Clostridioides difficile, spread by spores that resist alcohol hand rub and require soap-and-water handwashing and sporicidal cleaning. Water sources point to Legionella and Pseudomonas; contaminated respiratory equipment to Burkholderia. Prevention is bundle-based: hand hygiene above all, chlorhexidine skin preparation, maximal sterile barriers and prompt removal of lines and catheters, head-of-bed elevation and sedation interruption for ventilated patients, and antimicrobial stewardship.
Sources
- Harrison's Principles of Internal Medicine
- Levinson Medical Microbiology and Immunology
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