> Table of Contents > Nosocomial Infections
Nosocomial Infections
Cheryl Durand, PharmD
Edward L. Yourtee, MD, FACP
image BASICS
  • 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 (C. diff, C. difficile, CDAD, CDI)
  • 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.
  • General
    • 13/1,000 patient-days in the ICU (1)
    • 7/1,000 patient-days in high-risk nurseries
    • 2.6/1,000 patient-days in nurseries (1)
    • Estimated cost of HAIs is $20 billion per year (2).
  • Infection specific
    • CAUTI
      • Hospital stay increased by 1 to 3 days.
      • Cost up to $600/infection
    • VAP
      • Hospital stay increased by 6 days.
      • Cost up to $5,000/infection
    • CLABSI
      • Hospital stay increased by 7 to 20 days.
      • Cost up to $56,000/infection
    • SSI
      • Hospital stay increased by 7.3 days.
      • Cost >$3,000/infection
      • May not be apparent until 1 month after surgery
    • C. difficile infection (see topic Clostridium difficile Infection”)
  • 1 out of 25 inpatients in the United States has at least one HAI (3).
    • 722,000 HAIs in U.S. acute care hospitals in 2011 (3)
    • UTI: 13% of HAIs (3)
    • Pneumonia: 22% of HAIs (3)
    • Bloodstream infection: 10% of HAIs (3)
    • SSI: 22% of HAIs (3)
    • 107,000 C. difficile cases in 2011(4)[A]
  • 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.
  • 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 (3)
    • Pneumonia: aerobic gram-negative bacilli, Staphylococcus aureus, P. aeruginosa, Streptococcus spp. (3)
    • Bloodstream infection: Staphylococcus spp., Candida spp., Enterococcus spp., gram-negative bacilli (3)
    • SSI: S. aureus, gram-negative bacilli, Enterococcus spp., Streptococcus spp., Enterobacter spp., Bacteroides spp. (3)
  • 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
  • Prevention should target both patient-specific and facility-related risk factors.
  • Hand hygiene—thoroughly wash hands (5)[C]
    • On entering and leaving any patient room (5)
    • After contact with blood, excretions, body fluids, wound dressings, nonintact skin, mucous membranes (5)
    • Before using and after removing gloves (gloves are permeable to bacteria)
    • When moving hands from contaminated to clean body site (5)
    • Alcohol-based products are satisfactory when hands are not visibly soiled (5).
    • 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 C. difficile infection (2).
    • 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 (5)[C]
  • Employee education on HAIs (5)[C]
  • Disinfection of 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 (5)[A]
    • Contact precautions
      • Institute for known pathogens spread by direct contact including methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus (VRE), C. difficile, extended-spectrum &bgr;-lactamase-producing gram-negative rods, and carbapenemase-producing gram-negative rods. Glove when entering room (5)[B]
      • Gown if clothing will touch patient or environment (5)[B]
    • Droplet precautions
      • Infectious particles measure >5 &mgr;m.
      • 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 (5)[B]
    • Airborne precautions
      • Infectious particles measure <5 &mgr;m.
      • Institute for pathogens shed via coughing including tuberculosis, varicella-zoster virus, and measles.
      • Fit-tested National Institute of Occupational Safety and Health (NIOSH)-approved ≥ N-95 respirator on entering room (5)[B]
  • Infection-specific measures
    • CAUTI
      • Employee education on urinary catheters (indications, placement, maintenance)
      • Sterile catheter placement technique (6)[C]
      • Closed urine collection system (6)[C] Use catheter only for necessary duration and remove as early as possible (6)[B].
      • Use of nurse-driven protocols for guidelinedriven catheter removal.
      • Do not confuse catheter-associated asymptomatic bacteriuria with CAUTI.
      • Do not screen for bacteriuria by routinely performing a urine culture when the catheter is withdrawn.
    • VAP
      • Intubate only when clinically necessary (7)[C]
      • Perform oral decontamination with oral chlorhexidine (8)[A].
      • Avoid nasotracheal intubation (7)[B].
      • Inline suctioning (7)[C]
      • Elevate head to 30 to 45 degrees (7)[C].
    • CLABSI
      • Educate staff about appropriate use of IV catheters (indications, placement, maintenance) (9)[A]. Place catheters using sterile technique (including chlorhexidine prep and maximal barrier precautions) (9)[A].
      • Use order “bundles” to improve adherence to catheter insertion guidelines.
      • Remove catheter promptly when no longer clinically indicated (9)[A].
      • Hand hygiene in addition to glove use (9)[A]
      • Regularly monitor catheter site (9)[A].
      • With introduction of these measures, CLASBI rates fell 46% between 2008 and 2011 (10)[A].
    • SSI
      • Proper surgical hand hygiene (2)[B]
      • Prophylactic antibiotic therapy when indicated (2)[A]; eliminate underlying infections before surgery if possible (2)[A].
      • P.721

      • Remove hair with electric clippers/depilatory agent prior to incision (2)[B].
      • Poor postoperative blood sugar control increases risk of infection.
    • C. difficile infection
      • Gloves combined with hand hygiene with soap and water (spores are resistant to alcohol-based products) (2)
      • Restrict use of fluoroquinolones, cephalosporins, and clindamycin when possible (2).
      • C. difficile is associated with the use of proton pump inhibitors: H2 blockers is preferred for acid suppression (11)[A].
      • Probiotics may reduce nonspecific antibioticassociated diarrhea; the effectiveness of probiotics for prevention of C. difficile is unclear (11).
    • Bloodstream infections
      • Use of chlorhexidine-impregnated washcloths to bathe ICU patients reduces bloodstream infections by 28% (12)[B].
      • Routine surveillance for systemic inflammatory response syndrome (SIRS) using established criteria
Consistent with nature of infection
Consistent with nature of infection; site-specific exam for infections of skin, catheter sites, wounds, signs of sepsis, or pneumonia
  • Community-acquired infection
  • Sepsis/SIRS
  • Other causes of infectious diarrhea
Specific to condition
  • CBC, blood culture
  • Wound culture
  • Urine culture
  • Chest x-ray
  • Stool culture
Test Interpretation
Consistent with underlying infection
  • Treat with appropriate antibiotics.
  • Order bundles improve adherence to sepsis guidelines and improves survival.
  • UTI: Remove urinary catheters.
  • CLABSI: Remove IV catheter.
  • C. difficile: Stop all antibiotics not being used to treat C. difficile infection.
First Line
  • Targeted antimicrobial therapy
  • Several agents have been recently approved for the treatment of antibiotic-resistant infections and should be considered for second-line therapy.
    • Daptomycin, telavancin, dalbavancin, ceftaroline, oritavancin, tedizolid, ceftolozane-tazobactam, and ceftazidime-avibactam
  • Failure to respond to initial therapy
  • Some emerging resistant gram-negative infections are resistant to nearly all antibiotics and require expert consultation for management.
  • Screening for nasal carriage and isolation reduce the nosocomial spread of MRSA.
  • Treating proven nasal carriers of Staphylococcus or MRSA with mupirocin prevents S. aureus nosocomial infections after surgery, as long as the prevalence of mupirocin resistance is low (13)[B].
IV Fluids
As needed for hemodynamic support
  • Hand washing should be performed on entering and exiting the patient room even when there is no direct contact with the patient.
  • Isolation precautions as indicated
Discharge Criteria
When infection has resolved or patient is stable and not an infectious risk
Patient Monitoring
Risk for recurrence is generally low in immunocompetent patients. Manage underlying comorbidities (risk factors).
  • 99,000 deaths in 2002 in the United States (1)
  • Bloodstream infection mortality: 27%
  • Pneumonia mortality: 33-50%
  • SSI mortality: 11%
1. Klevens RM, Edwards JR, Richards CL Jr, et al. Estimating health care-associated infections and deaths in U.S. hospitals, 2002. Public Health Rep. 2007;122(2):160-166.
2. Yokoe DS, Mermel LA, Anderson DJ, et al. A compendium of strategies to prevent healthcare-associated infections in acute care hospitals. Infect Control Hosp Epidemiol. 2008;29(Suppl 1):S12-S21.
3. Magill SS, Edwards JR, Bamberg W, et al. Multistate point-prevalence survey of health care-associated infections. N Engl J Med. 2014;370(13): 1198-1208.
4. Lessa FC, Mu Y, Bamberg WM, et al. Burden of Clostridium difficile infection in the United States. N Engl J Med. 2015;372(9):825-834.
5. Siegel JD, Rhinehart E, Jackson M, et al. 2007 guideline for isolation precautions: preventing transmission of infectious agents in health care settings. Am J Infect Control. 2007;35(10)(Suppl 2): S65-S164.
6. Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheterassociated urinary tract infection in adults: 2009 international clinical practice guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(5):625-663.
7. Tablan OC, Anderson LJ, Besser R, et al. Guidelines for preventing health-care associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR Recomm Rep. 2004;53(RR-3):1-36.
8. Chan EY, Ruest A, Meade MO, et al. Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis. BMJ. 2007;334(7599):889.
9. O' Grady NP, Alexander M, Burns LA, et al. 2011 Guidelines for the Prevention of Intravascular Catheter-Related Infections. www.cdc.gov/hicpac/BSI/01-BSI-guidelines-2011.html. Accessed 2011.
10. Centers for Disease Control and Prevention. 2013 National and State Healthcare-Associated Infections Progress Report. www.cdc.gov/hai/progress-report/index.html.
11. Surawicz CM, Brandt LJ, Binion DG, et al. Guidelines for diagnosis, treatment, and prevention of Clostridium difficile infections. Am J Gastroenterol. 2013;108(4):478-498.
12. Climo MW, Yokoe DS, Warren DK, et al. Effect of daily chlorhexidine bathing on hospital-acquired infection. N Engl J Med. 2013;368(6):533-542.
13. van Rijen M, Bonten M, Wenzel R, et al. Mupirocin ointment for preventing Staphylococcus aureus infections in nasal carriers. Cochrane Database Syst Rev. 2008;(4):CD006216.
  • T83.51XA Infect/inflm reaction due to indwell urinary catheter, init
  • T81.4XXA Infection following a procedure, initial encounter
  • J95.851 Ventilator associated pneumonia
Clinical Pearls
  • Nosocomial infections increase mortality, length of hospital stay, and cost of hospitalization.
  • Preventive efforts should address patient-specific and facility-related risk factors.
  • Proper hand hygiene, using an alcohol-based hand product or soap and water should be carried out before and after each patient encounter, even when gloves are used. Alcohol-based hand rubs are not effective for killing spores formed by C. difficile. Hand washing with soap and water is preferred in this situation.
  • Adherence to contact, droplet, or airborne precautions reduces the spread of infection.
  • The risk of developing a resistant nosocomial infection can be reduced by antibiotic streamlining, use of narrow-spectrum antibiotics, and frequent patient reevaluation to ensure the necessity of continuing antibiotics.