Nosocomial Infections – Causes, Symptoms, Diagnosis, Treatment and Ongoing care

Basics

Description

Also known as health care–associated infections (HAIs)Infection must not have been present or incubating on admission to health care facilityCenters for Disease Control and Prevention (CDC) categories: Urinary tract infection (UTI)Surgical-site infection: Superficial or deep incisional-site infectionOrgan/space infectionPneumoniaBloodstream infectionBone and joint infectionCNS infectionCardiovascular system infectionEar, eye, nose throat, or mouth infectionGI system infectionLower respiratory system infection (excluding pneumonia)Reproductive tract infectionSkin and soft tissue infectionSystemic infectionThe National Healthcare Safety Network (NHSN) at www.cdc.gov/nhsn monitors the epidemiology of emerging HAI pathogens, HAI pathogens, and their mechanisms of resistance and evaluates alternative surveillance and prevention strategies.

Epidemiology

General: 13/1,000 patient-days in ICU (1)6.9/1,000 patient-days in high-risk nurseries (2)2.6/1,000 patient-days in nurseries (1)Estimated cost of HAIs is $20 billion per year (3).Infection-specific: UTI: Hospital stay increased by 1–3 daysCost up to $600 per infectionPneumonia: Hospital stay increased by 6 daysCost up to $5,000 per infectionBloodstream infection: Hospital stay increased by 7–20 daysCost up to $56,000 per infection (4)Surgical-site infection: Hospital stay increased 7.3 daysCost >$3,000 per infectionMay not be apparent until 1 month after surgeryClostridium difficile infection (see topic “Clostridium Difficile Infection”)

Incidence

Incidence of resistant Staphylococcus aureus and vancomycin-resistant Enterococcus has been increasing dramatically in the last 15 years.1.7 million HAIs in 2002 (1)5–10% of hospital stays are complicated by HAIs (3).HAIs are among the top 10 leading causes of death in the US (3).The majority of patients affected have a single-site infection.UTI: 36% of HAIs (1): 424,060 cases in 2002 in US (1)2.39/100 admissionsPneumonia: 11% of HAIs (1): 129,519 cases in 2002 in US (1)0.60/100 admissionsBloodstream infection: 11% of HAIs (1): 133,368 cases in 2002 in US (1)0.27/100 admissionsSurgical-site infection: 20% of HAIs (1): 244,385 cases in 2002 in US (1)3% of all surgeries (2)20% of emergency abdominal surgeries (2)Others: 22% of HAIs (1): 263,810 cases in 2002 in US (1)Resistance rates are increasing among several problematic gram-negative pathogens that are often responsible for serious nosocomial infections (5).In 2008, 70% of nosocomial infections were resistant to at least one antimicrobial drug that was effective previously (6).

Risk Factors

Extremes of ageChronic disease (including diabetes, renal failure, and malignancy)ImmunodeficiencyMalnutritionMedications such as antibiotics, antacids, and sedativesColonization with pathogenic strains of floraBreakdown of mucosal or cutaneous barriersAnesthesia

General Prevention

Prevention efforts should address both patient-specific and facility-related risk factors.Hand hygiene: Before direct patient contact (7)[B]After contact with blood, excretions, body fluids, wound dressings, nonintact skin, mucous membranes (7)[A]After contact with intact skin (7)[B]When hands will be moving from contaminated to clean body site (7)[C]Alcohol-based product: When hands are not visibly soiled (7)[A]Soap and water: When visibly soiled (7)[A]When in contact with spores (7)[C]Hospital-based surveillance programsInfection control programs with specially trained employees (7)[B]Employee education on HAIs (7)[B]Minimize invasive procedures.Isolation of known pathogen carriers (7)[A]: Contact precautions: Pathogens spread by direct contactGloves when entering room (7)[B]Gown if clothing will touch patient or environment (7)[B]Includes methicillin-resistant S. aureus (MRSA), vancomycin-resistant Enterococcus, C. difficile, extended-spectrum ß-lactamase-producing gram-negative rodsDroplet precautions: Infectious particles measure >5 µmMask when entering room (7)[B]Shed via talking, coughing, sneezing, mucosal shedding, airway suctioning, bronchoscopyIncludes Neisseria meningitis, influenza, Haemophilus influenzae, diphtheria, Bordetella pertussisAirborne precautions: Infectious particles measure <5 µmFit-tested National Institute of Occupational Safety and Health (NIOSH)–approved N-95 or higher respirator on entering room (7)[B]Shed via coughingIncludes tuberculosis, varicella-zoster virus, measlesInfection-specific measures: UTI: Employee education on catheters (8)[C]Sterile catheter placement technique (8)[C]Closed urine collection system (8)[C]Use of catheter only as necessary (8)[B]Removal of catheter as early as possible (8)[B]Pneumonia: Intubation only as necessary (9)[C]Perform oral decontamination with an antiseptic agent (10)[A].Avoidance of nasotracheal intubation (9)[B]In-line suctioning (9)[C]Head elevation of 30–45° (9)[C]Bloodstream infection: Employee education on catheters (4)[A] (e.g., indications, placement, maintenance)Sterile catheter placement technique (4)[A]Prompt removal of catheter (4)[A]Hand hygiene in addition to glove use (4)[A]Regular monitoring of catheter site (4)[B]Surgical-site infection: Proper surgical hand hygiene (3)[B]Prophylactic antibiotic therapy when indicated (3)[A]Elimination of underlying infections before surgery (3)[A]Hair removal with electric clippers or depilatory agent (3)[B]Postoperative blood sugar control

Pathophysiology

Endogenous spread: Patient’s own normal flora causes invasive disease (majority of cases).Exogenous route: Flora from within health care facility causes invasive disease.

Etiology

UTI: Escherichia coli, Klebsiella spp., Serratia spp., Enterobacter, Pseudomonas aeruginosa, Enterococcus spp., Candida albicansPneumonia: Aerobic gram-negative bacilli, S. aureus, P. aeruginosaBloodstream infection: Staphylococcus spp.Surgical-site infection: S. aureus, gram-negative bacilli

Diagnosis

Consistent with nature of infection

History

Exposure to health care facilityRecent surgeryHistory of invasive procedure: Urinary catheter placementIn-dwelling vascular catheterRecent intubation/mechanical ventilationPast infections (e.g., MRSA)

Physical Exam

Consistent with nature of infection

Diagnostic Tests & Interpretation

As appropriate for suspected infection

Pathological Findings

Consistent with underlying infection

Differential Diagnosis

Community-acquired infectionNoninfectious process

Treatment

Medication

As appropriate for specific nature of infectionSeveral agents have been approved recently for the treatment of antibiotic-resistant gram-positive infections: linezolid, daptomycin, telavancin, and tigecycline.

Additional Treatment

General Measures

Treat the underlying infection as indicated.

Issues for Referral

As appropriate

Surgery/Other Procedures

As appropriate for specific nature of infectionTreating proven carriers of S. aureus with mupirocin prevents S. aureus nosocomial infections after surgery. This screen-and-treat approach is cost saving as long as the prevalence of mupirocin resistance is low (11)[B].

In-Patient Considerations

IV Fluids

As needed

Nursing

As applicable

Discharge Criteria

When infection has resolved or patient is stable

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

As appropriate for specific type of infection

Prognosis

99,000 deaths in 2002 in US (1)Bloodstream infection mortality: 27% (12)Pneumonia mortality: 33–50% (13)Surgical-site infection mortality: 11% (1)

Complications

Related to specific nature of infection

References

1. Klevens RM, Edwards JR, Richards CL, et al. Estimating health care-associated infections and deaths in U.S. hospitals, 2002. Public Health Rep. 2007;122:160–6.

2. Barie PS, Eachempati SR. Surgical site infections. Surg Clin North Am. 2005;85:1115–35, viii-ix.

3. Society for Healthcare Epidemiology of America; Infectious Diseases Society of America. A compendium of strategies to prevent healthcare-associated infections in acute care hospitals. Infect Control Hosp Epidemiol. 2008;29(suppl 1):S1–S92.

4. O’Grady NP, et al. Guidelines for the prevention of intravascular catheter-related infections. MMRW Recommendations and Reports. 2002;51:1–32.

5. Slama TG. Gram-negative antibiotic resistance: there is a price to pay. Crit Care. 2008;12(Suppl 4):S4.

6. Carmeli Y. Strategies for managing today’s infections. Clin Microbiol Infect. 2008;14(Suppl 3):22–31.

7. 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:S65–164.

8. Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, Prevention, and Treatment of Catheter-Associated Urinary Tract Infection in Adults: 2009 International Clinical Practice Guidelines from the Infectious Disease Society of America. Clin Infect Dis. 2010;50:625–663.

9. Tablan OC, et al. Guidelines for preventing health-care associated pneumonia, 2003: Recommendations of CDC and the healthcare infection control practices advisory committee. MMWR Recommendations and Reports. 2004;53:1–40.

10. 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;334:889.

11. Van Rijen M, Bonten M, Wenzel R, et al. Mupirocin Ointment for Preventing Staphylococcus aureus Infections in Nasal Carriers. Cochrane Database Syst Rev. 2009;1:CD006216.

12. Wisplinghoff H, Bischoff T, Tallent SM, et al. Nosocomial bloodstream infections in US hospitals: analysis of 24,179 cases from a prospective nationwide surveillance study. Clin Infect Dis. 2004;39:309–17.

13. American Thoracic Society, Infectious Diseases Society of America. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med. 2005;171:388–416.

Additional Reading

Tacconelli E. Screening and isolation for infection control. J Hosp Infect. 2009.

Codes

ICD9

486 Pneumonia, organism unspecified599.0 Urinary tract infection, site not specified998.59 Other postoperative infection999.31 Infection due to central venous catheter

Snomed

19168005 nosocomial infectious disease (disorder)68566005 urinary tract infectious disease (disorder)425464007 nosocomial pneumonia (disorder)33910007 postoperative infection (disorder)431193003 infection of bloodstream (disorder)

Clinical Pearls

Nosocomial infections are associated with increased mortality, length of stay, and admission cost.Prevention efforts should address both patient-specific and facility-related risk factors.Proper use of an alcohol-based hand product should be carried out before and after each patient encounter, even when gloves are used.Contact, droplet, or airborne precautions should be employed when appropriate to reduce the spread of infection.The risk of developing a resistant nosocomial infection can be reduced with judicious use of antibiotics in the health care setting.