Nosocomial infection
A nosocomial infection, also called healthcare-associated or hospital-acquired infections, refers to an infection which was not present during the time of admission, that the patient has acquired in an institution like a hospital. A nosocomial epidemic is a nosocomial infection that affects two or more patients, and there is a connection between the cases.
Problems with nosocomial infections:
- Many people in small area
- Hospitalized people often have impaired immunity or condition
- Microorganisms in the hospital often have increased resistance to antibiotics
- Microorganisms in the hospital are often more virulent than microorganisms in the community
Although intensive care units (ICUs) account for fewer than 10% of total beds in most hospitals, more than 20% of all nosocomial infections are acquired in ICUs. ICU-acquired infections account for substantial morbidity, mortality, and expense. Most bacterial infections that occur on the ICU have some sort of anti-microbial resistance.
Primary and secondary factors
Primary factors:
- Source of nosocomial infection
- The patients themselves
- From commensal bacteria
- Other patients
- Staff
- Visitors
- Medical equipment
- Bedsheets
- The patients themselves
- Route of transmission
- Direct contact
- Indirect
- Airborne
- Waterborne
- Foodborne
- Objects, instruments
- Clothing
- Bedsheets
- Susceptible population
- High number of susceptible people
- Infants
- Elderly
- Immunocompromised
- Diabetes mellitus
- Cancer
- Polytrauma
- Surgical patients
Secondary factors:
- Crowded rooms
- Insufficient number of cleaning and nursing staff
- Lack of medical staff’s preventive approach
Types
Most common infections:
- Catheter-associated UTI
- Ventilator-associated pneumonia (VAP) – occurs > 48 hours after initiation of invasive ventilation
- Gram-negatives (pseudomonas, E. coli)
- S. aureus
- Catheter-related bloodstream infection (CRBSI)
Pathogens
Most problematic pathogens:
- Vancomycin-resistant enterococci (VRE)
- MRSA
- Pseudomonas aeruginosa
- Multidrug-resistant gram-negative bacteria
Risk factors
- Patients in poor condition
- Invasive interventions and devices
- Older age
- Comorbidities
- Long duration of hospitalization
- Antibiotic use
Prevention
- Risk stratification
- Avoid invasive procedures when possible
- Discontinue indwelling sources of infection when possible
- Reducing person-to-person transmission
- Disinfection of hands
- Before, during and after patient contact
- Disinfection = reduce the number of microorganisms, killing most harmful microorganisms
- Sterilization = kill all microorganisms
- Personal hygiene
- Protective equipment
- Disinfection of hands
- Preventing transmission from the environment
- Asepsis, antisepsis, isolation of patients
- Ensure sterility during procedures
- Sterilization of equipment
- Limit overuse of antibiotics
- Education and training of medical staff