The most common cause of nosocomial infection is?

SGPGI Nursing Officer-2022

Applied Microbiology & Infection control

Easy

Appeared in: SGPGI Nursing Officer-2022

Explanation

Staphylococcal bacteria, specifically Staphylococcus aureus, are the leading cause of nosocomial infections when all types are considered collectively.
This organism is a major pathogen in several high-risk HAIs, including surgical site infections (SSIs), central line-associated bloodstream infections (CLABSIs), and ventilator-associated pneumonia (VAP).
Its presence as normal flora on the skin and in the nose provides a ready source for infection, particularly in patients with compromised skin integrity or invasive devices.
Methicillin-resistant Staphylococcus aureus (MRSA) is a particularly challenging drug-resistant strain that contributes significantly to the burden of HAIs.

Option A: While E. coli is a major pathogen in HAIs, it is not the most common cause overall. Its primary association is with urinary tract infections.
Option C: Hepatitis C is a bloodborne virus. It is not a common cause of general nosocomial infections, which are typically bacterial and spread through contact, respiratory, or device-related routes.
Option D: Similar to Hepatitis C, Hepatitis B is a bloodborne virus. It is transmitted via blood and body fluids and is not a leading cause of the most common types of HAIs like pneumonia, SSIs, or UTIs.

Clinical Relevance

Nursing practice connection: Knowing Most common causative agent of nosocomial (hospital-acquired) infections helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the most common pathogens in HAIs is critical for nurses to implement targeted infection control measures, such as meticulous hand hygiene and aseptic technique, especially when caring for patients with invasive devices.
Nurses play a key role in HAI prevention bundles, including daily assessments for the continued need for devices like urinary catheters and central lines, to reduce the risk of infection from organisms like S. aureus and E. coli.
Knowledge of common pathogens guides empiric antibiotic therapy. When a patient shows signs of an HAI, treatment often starts with drugs effective against likely organisms like S. aureus before culture results are available.

How to Approach the Question

First, identify the core of the question: it asks for the 'most common cause' of 'nosocomial infection' (hospital-acquired infection).
Evaluate each option based on your knowledge of microbiology and infection control.
Recognize that E. coli is very common, but primarily in one type of HAI (UTIs).
Recall that Staphylococcus is a versatile pathogen causing many types of HAIs, including SSIs, bloodstream infections, and pneumonia.
Dismiss Hepatitis B and C as they are bloodborne viruses and not typical causes of general HAIs.
Conclude that while E. coli causes the most frequent type of HAI, Staphylococcus is often cited as the most common single organism across all HAIs combined.

Concept Tested & Keywords

Concept Tested: Most common causative agent of nosocomial (hospital-acquired) infections.
Stem keywords: nosocomial infection, most common cause
Lead-in keywords: most common

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