Description

• Health care–associated infections (HAIs)
• Infection must not have been present or incubating on admission to a health care facility.
• CDC categories:
  • Catheter-associated urinary tract infection (CAUTI)
  • Surgical site infection (SSI)
  • Ventilator-associated pneumonia (VAP)
  • Central line–associated bloodstream infection (CLABSI)
  • Clostridium difficile infection (CDI; C. diff, C. difficile, CDAD)
• The National Healthcare Safety Network (NHSN) at www.cdc.gov/nhsn monitors emerging HAI pathogens and their mechanisms of resistance to promote current prevention strategies.
• Medicare and Medicaid will not pay for the treatment of certain HAI including CAUTIs, CLABSIs, and SSIs.

Epidemiology

• CAUTI
  • 0.2 to 4.8 per 1,000 catheter days
  • Hospital stay increased by 1 to 3 days
  • Cost up to $600 per infection
• VAP
  • 10% of ventilated patients develop VAP.
  • Hospital stay increased by 11 to 13 days
  • Cost up to $40,000 per infection
• CLABSI
  • 41,000 infections annually
  • Hospital stay increased by 7 to 20 days
  • Cost up to $56,000 per infection
• SSI
  • Hospital stay increased by 7.3 days
  • Cost >$3,000 per infection
  • May not be apparent until 1 month after surgery
• CDI (see topic “Clostridium Difficile Infection”)

Incidence

• 1 of 25 inpatients in the United States has at least one HAI (1).
  • 722,000 HAIs in U.S. acute care hospitals (2)
  • UTI: 13% of HAIs (2)
  • Pneumonia: 22% of HAIs (2)
  • Bloodstream infection: 10% of HAIs (2)
  • SSI: 22% of HAIs (3)
  • C. difficile infection: 12% of HAIs (2). Infections caused by gram-negative rods resistant to almost all antibiotics are increasing. Up to 70% of nosocomial infections are resistant to at least one previously active antimicrobial.

Etiology and Pathophysiology

• Endogenous spread: Patient host flora causes invasive disease (most common).
• Exogenous spread: flora acquired from within health care facility
• Causative organisms
  • UTI: Escherichia coli, Klebsiella spp., Serratia spp., Enterobacter, Pseudomonas aeruginosa, Enterococcus spp., Candida albicans (2)
  • Pneumonia: aerobic gram-negative bacilli, Staphylococcus aureus, P. aeruginosa, Streptococcus spp. (2)
  • Bloodstream infection: Staphylococcus spp., Candida spp., Enterococcus spp., gram-negative bacilli (2)
  • SSI: S. aureus, gram-negative bacilli, Enterococcus spp., Streptococcus spp., Enterobacter spp., Bacteroides spp. (2)

Risk Factors

• Extremes of age
• Invasive surgical procedures (abdominal surgeries, orthopedic surgeries, urogynecologic surgeries, neurosurgery)
• Use of indwelling medical devices
• Chronic disease (including diabetes, renal failure, and malignancy)
• Immunodeficiency
• Malnutrition
• Medications (recent antibiotics, proton pump inhibitors, and sedatives)
• Colonization with pathogenic strains of flora
• Breakdown of mucosal/cutaneous barriers, including trauma and battle wounds
• Anesthesia
• Lack of attention to detail with universal precautions

General Prevention

• Prevention should target both patient-specific and facility-related risk factors.
• Hand hygiene—thoroughly wash hands (1)[B].
  • On entering and leaving any patient room (4)
  • After contact with blood, excretions, body fluids, wound dressings, nonintact skin, mucous membranes (4)
  • Before using and after removing gloves (gloves are permeable to bacteria)
  • When moving hands from contaminated to clean body site (4)
  • Alcohol-based products are satisfactory when hands are not visibly soiled (4).
  • Soap and water should be used when surfaces are visibly soiled or when contact with spores is anticipated.
• Antibiotic stewardship—appropriate selection of antimicrobial therapy includes the following:
  • Judicious use of antibiotics to reduce the emergence of multidrug-resistant organisms and the occurrence of CDI
  • Use of narrow-spectrum early-generation antibiotics when possible
  • Taking an antibiotic “time out” at 72 hours to review the patient’s clinical status and culture results and eliminate (“streamline”) any redundant or unnecessary antibiotics
  • Use shorter courses of antibiotics when appropriate.
• Hospital-based surveillance programs and antibiograms
• Infection control programs with specially trained employees (4)
• Employee education on prevention of HAIs (4)
• Disinfect hospital rooms with hydrogen peroxide vapor or UV irradiation in addition to standard cleaning reduces environmental contamination and the risk of infection with multidrug-resistant organisms.
• Minimize invasive procedures.
• Caregiver stethoscope cleaning
  • Stethoscope bacterial contamination is common. Regular cleaning with alcohol-based preparations reduces bacterial load. Evidence is lacking to confirm whether stethoscope contamination causes nosocomial infections.
• Isolation of known pathogen carriers (4)[A]
  • Contact precautions
    • Important for pathogens spread by direct contact including methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus (VRE), C. difficile, extended-spectrum β-lactamase–producing gram-negative rods, and carbapenemase-producing gram-negative rods
    • Glove when entering room (4)[B]
    • Gown if clothing will touch patient or environment (4)[B]
  • Droplet precautions
    • Infectious particles measure >5 μm.
    • Institute for pathogens shed via talking, coughing, sneezing, mucosal shedding, airway suctioning, and bronchoscopy. These include Neisseria meningitidis, influenza, Haemophilus influenzae, Corynebacterium diphtheriae, and Bordetella pertussis.
    • Mask when entering room (4)[B].
  • Airborne precautions
    • Infectious particles measure <5 μm.
    • Institute for pathogens shed via coughing including tuberculosis, varicella-zoster virus, and measles.
    • Fit-tested National Institute for Occupational Safety and Health (NIOSH)-approved ≥ N95 respirator on entering room (4)[B]
• Infection-specific measures
  • CAUTI
    • Employee education, training, and written guidelines on urinary catheters (indications, placement, maintenance) (5)[C]
    • Sterile catheter placement technique (5)[C]
    • Closed urine collection system (5)[C]
    • Use catheter only for necessary duration and remove as early as possible (5)[B].
    • Nurse-driven protocols for catheter removal
    • Document indication, date of insertion, name of person performing insertion, daily catheter checks, and justification for ongoing use (1)[C].
    • Do not confuse catheter-associated asymptomatic bacteriuria with CAUTI.
    • Do not screen for bacteriuria with routine urine culture at time of catheter removal.
  • VAP
    • Intubate only when necessary; use noninvasive positive pressure ventilation if possible (1)[A].
    • Perform oral decontamination with oral chlorhexidine (1)[B].
    • Minimize the need for sedation (1)[B] and provide daily interruption of sedation (1)[A].
    • Provide exercise and ambulation early (1)[B].
    • Elevate head to 30 to 45 degrees (1)[C].
  • CLABSI
    • Educate staff about appropriate use of IV catheters (indications, placement, maintenance) (1)[B].
    • Place catheters using sterile technique (including chlorhexidine prep (1)[A] and maximal barrier precautions) (1)[B].
    • Use order “bundles” to improve adherence to catheter insertion guidelines.
    • Daily chlorhexidine bath; chlorhexidine dressing for patients >2 months old (1)[A]
    • Promptly remove catheter when no longer clinically indicated (1)[B].
    • Hand hygiene/glove use
    • Regularly monitor catheter site (1)[A].
  • SSI
    • Proper surgical hand hygiene (1)[B]
    • Prophylactic antibiotic therapy when indicated (1)[A]; eliminate underlying infections before surgery if possible (1)[A].
    • Remove hair with electric clippers/depilatory agent prior to incision (1)[B].
    • Poor postoperative blood sugar control increases risk of infection (1)[B].
  • CDI
    • Gloves combined with hand hygiene with soap and water (Spores are resistant to alcohol-based products.) (1)
    • Continue contact precautions for at least 48 hours after diarrhea has resolved (6)[C].
    • Limit use of fluoroquinolones, cephalosporins, and clindamycin if possible (6)[B].
    • C. difficile is associated with the use of proton pump inhibitors: H₂ blockers are preferred for acid suppression (6).