Healthcare-Associated Infections - Nosocomial Infections

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Topics

Indications for Testing

  • Clinical deterioration and/or new onset fever in a hospitalized patient

Laboratory Testing

  • Initial testing – CBC, urine, and blood culture
  • Specific site testing based on clinical situation – refer to CDC/NHSN Surveillance Definitions for Specific Types of Infections publication
    • Use of CDC definitions may be helpful in defining patient healthcare-associated infections (HAI)
  • Bacterial strain characterization – aid in identification of outbreak source to optimize infection control and prevention efforts

Imaging Studies

  • Chest x-ray – rule out pneumonia
  • Further imaging may be necessary based on clinical presentation

Healthcare-associated infections (HAI) develop as a result of a stay in a hospital or healthcare facility and are often caused by organisms resistant to standard antibiotic/antifungal therapies. Outbreaks in hospitals and extended-care facilities may spread to the general community and can cause substantial morbidity and mortality.


  • Prevalence – 5-10% of patients admitted to U.S. hospitals develop HAI (CDC, 2014)
  • Incidence – >700,000 cases annually (CDC, 2014)
  • Transmission – acquisition of HAI may occur from poor hand hygiene, prosthetic devices, inadequate decontamination of fomites (eg, doorknobs, handrails)

Distribution of Infections (CDC, 2014)

  • Adults
    • Urinary tract – 13%
    • Surgical site – 22%
    • Lung – 22%
    • Bloodstream – 10%
    • Gastrointestinal illness – 17%
    • Other – 16%
  • Children
    • Higher rates of bloodstream, viral, and lower respiratory tract infections than in adults
    • Lower rates of catheter-related urinary tract infections, ventilator-associated pneumonia, and surgical-site infections

Clinical Presentation

  • Nonspecific
    • Worsening clinical condition with no distinct symptoms; fever or hypothermia
  • Site-specific  symptoms
    • Pneumonia – new infiltrates on chest x-ray; worsening oxygenation
    • Meningitis – altered consciousness, irritability, seizures
    • Site infections – purulent drainage, site pain


Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

CBC with Platelet Count 0040002
Method: Automated Cell Count

Urine Culture 0060131
Method: Culture/Identification


Gram stain is performed by request only; results indicate colony count plus identification of significant isolates

For invasively or straight catheter collected urine specimens, order the urine culture with invasive collection

Blood Culture 0060102
Method: Continuous Monitoring Blood Culture/Identification


Testing is limited to only the University of Utah Health Sciences Center

Low volume will result in decreased recovery of pathogens

Bronchoscopy Culture and Gram Stain 0060700
Method: Quantitative Culture/Identification

Wound Culture and Gram Stain 0060132
Method: Stain/Culture/Identification


Anaerobe culture is NOT included with this order

Bacterial Strain Characterization by Pulsed-Field Gel Electrophoresis 0060182
Method: Pulsed-Field Gel Electrophoresis

Carbapenem-Resistant Organism Culture 2011418
Method: Culture/Identification

Antimicrobial Susceptibility - Carbapenemase Gene Detection by PCR 2014277
Method: Qualitative Polymerase Chain Reaction


CDC/NHSN Surveillance Definitions for Specific Types of Infections. Centers for Disease Control and Prevention. Atlanta, GA [Modified Apr 2015; Accessed: Feb 2017]

Hooton TM, Bradley SF, Cardenas DD, Colgan R, Geerlings SE, Rice JC, Saint S, Schaeffer AJ, Tambayh PA, Tenke P, Nicolle LE, Infectious Diseases Society of America. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis. 2010; 50(5): 625-63. PubMed

Horan TC, Andrus M, Dudeck MA. CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting. Am J Infect Control. 2008; 36(5): 309-32. PubMed

Mermel LA, Allon M, Bouza E, Craven DE, Flynn P, O'Grady NP, Raad II, Rijnders BJ, Sherertz RJ, Warren DK. Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2009; 49(1): 1-45. PubMed

General References

Amin A, Kollef MH. Health care-associated pneumonia. Hosp Pract (1995). 2010; 38(3): 63-74. PubMed

Attridge RT, Frei CR. Health care-associated pneumonia: an evidence-based review. Am J Med. 2011; 124(8): 689-97. PubMed

Carey AJ, Saiman L, Polin RA. Hospital-acquired infections in the NICU: epidemiology for the new millennium. Clin Perinatol. 2008; 35(1): 223-49, x. PubMed

Chopra I, Schofield C, Everett M, O'Neill A, Miller K, Wilcox M, Frère J, Dawson M, Czaplewski L, Urleb U, Courvalin P. Treatment of health-care-associated infections caused by Gram-negative bacteria: a consensus statement. Lancet Infect Dis. 2008; 8(2): 133-9. PubMed

Doshi RK, Patel G, Mackay R, Wallach F. Healthcare-associated Infections: epidemiology, prevention, and therapy. Mt Sinai J Med. 2009; 76(1): 84-94. PubMed

Healthcare-associated Infections (HAI). Centers for Disease Control and Prevention. Atlanta, GA [Last updated May 2016; Accessed: Dec 2016]

Hsu V. Prevention of health care-associated infections. Am Fam Physician. 2014; 90(6): 377-82. PubMed

Kaul DR, Flanders SA, Beck JM, Saint S. Brief report: incidence, etiology, risk factors, and outcome of hospital-acquired fever: a systematic, evidence-based review. J Gen Intern Med. 2006; 21(11): 1184-7. PubMed

Kieninger AN, Lipsett PA. Hospital-acquired pneumonia: pathophysiology, diagnosis, and treatment. Surg Clin North Am. 2009; 89(2): 439-61, ix. PubMed

Kluytmans J, Struelens M. Meticillin resistant Staphylococcus aureus in the hospital. BMJ. 2009; 338: b364. PubMed

Lobdell KW, Stamou S, Sanchez JA. Hospital-acquired infections. Surg Clin North Am. 2012; 92(1): 65-77. PubMed

Tenover FC, Arbeit RD, Goering RV, Mickelsen PA, Murray BE, Persing DH, Swaminathan B. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol. 1995; 33(9): 2233-9. PubMed

Vidor C, Awad M, Lyras D. Antibiotic resistance, virulence factors and genetics of Clostridium sordellii. Res Microbiol. 2015; 166(4): 368-74. PubMed

Wenzel RP. Health care-associated infections: major issues in the early years of the 21st century. Clin Infect Dis. 2007; 45 Suppl 1: S85-8. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Jackson BR, Thomas A, Carroll KC, Adler FR, Samore MH. Use of strain typing data to estimate bacterial transmission rates in healthcare settings. Infect Control Hosp Epidemiol. 2005; 26(7): 638-45. PubMed

Medical Reviewers

Last Update: July 2017