> Table of Contents > Nosocomial Infections
Nosocomial Infections
Cheryl Durand, PharmD
Edward L. Yourtee, MD, FACP
image BASICS
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 (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.
EPIDEMIOLOGY
  • 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”)
Incidence
  • 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.
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 (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)
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 (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
image DIAGNOSIS
Consistent with nature of infection
PHYSICAL EXAM
Consistent with nature of infection; site-specific exam for infections of skin, catheter sites, wounds, signs of sepsis, or pneumonia
DIFFERENTIAL DIAGNOSIS
  • Community-acquired infection
  • Sepsis/SIRS
  • Other causes of infectious diarrhea
DIAGNOSTIC TESTS & INTERPRETATION
Specific to condition
  • CBC, blood culture
  • Wound culture
  • Urine culture
  • Chest x-ray
  • Stool culture
Test Interpretation
Consistent with underlying infection
image TREATMENT
GENERAL MEASURES
  • 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.
MEDICATION
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
ISSUES FOR REFERRAL
  • Failure to respond to initial therapy
  • Some emerging resistant gram-negative infections are resistant to nearly all antibiotics and require expert consultation for management.
SURGERY/OTHER PROCEDURES
  • 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].
INPATIENT CONSIDERATIONS
IV Fluids
As needed for hemodynamic support
Nursing
  • 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
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
Risk for recurrence is generally low in immunocompetent patients. Manage underlying comorbidities (risk factors).
PROGNOSIS
  • 99,000 deaths in 2002 in the United States (1)
  • Bloodstream infection mortality: 27%
  • Pneumonia mortality: 33-50%
  • SSI mortality: 11%
REFERENCES
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.
Codes
&NA;
ICD10
  • 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
&NA;
  • 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.