Hospital-Acquired Infections - PowerPoint

					Hospital-Acquired Infections

           Dr. A.O. Onipede
  Department of Medical Microbiology. O.AU.


   The primary role of an infection-control
    program is to reduce the risk of HAI,
    thereby protecting patients, employees,
    health care students, and visitors.

   Infection prevention and control (IPC) is a
    process of developing and implementing
    safe, evidence-based practice towards
    improving quality health care.              2

   Nosocomial infections are those that
    originate or occur in a hospital or hospital-
    like setting.
       Hospital-acquired infections (HAIs)
       Health care associated infections
   Infections that do not originate from a
    patient's original admitting diagnosis.


   Infections that become clinically evident
    after 48 hours of hospitalization are
    considered HAI.
   Infections that occur after the patient's
    discharge from the hospital can be
    considered to have a nosocomial origin if
    the organisms were acquired during the
    hospital stay.
         Consequences of HAI:

   Prolong hospital stay (extra 4days)
   serious illness or death
   2.5 million infections /year
   250, 000 death/year

        Consequences of HAI:

   Adds > 4.5 billion $ to US NH care cost
   Additional antimicrobial therapy
   Patient becoming a source or reservoir
   HAI:5-15% all admission in the US (CDC)


   Nosocomial infections are estimated to
    occur in 5% of all acute-care
    hospitalizations; the incidence rate is 5
    infections per 1,000 patient-days.
   HAIs result in an additional 26,250 deaths
    (range 17,500-70,000) and an added
    expenditure in excess of $4.5 billion. (US)

    Reasons for increase in HAI:
   New cutting edge diagnostic & therapeutic
    technologies for prolonging life
   Population ages
   Compromised defenses
       high prevalence of pathogens
       high prevalence of compromised hosts
       efficient mechanisms of transmission from
        patient to patient * chains of transmission .

                   Burden of HAI
   Cost to Patient & Family
       Loss of physical function & mental aguish
       Loss of earnings
       Cost of alternative labour in the home
   Cost to state/country
       Loss of tax from earned income
       May pay hospital expenses
       Increased capital expenses for additional facilities

                 Burden of HAI

   Cost to the hospital directly from
    increased use of:
       Dressings
       Antibiotics
       Medical and nursing time
       Prolonged bed occupancy
       Indirect cost from laboratory, theater, CSSD,
        isolation and IC services

      Emergence of Nosocomial
Nosocomial agents        Period
Streptococcus pyogenes   World war 1
S. Aureus                1940-1950
GNB                      1970-1980
MRSA                     1985-
CoNS, Entrococcus spp    1990-
Vancomycin-resistant     1995-
Enterococci (VRE)x
         Nosocomial pathogens

       are primarily caused by opportunists ,
         Enterococcus spp.
         Escherichia coli
         Pseudomonas spp.
         Staphylococcus aureus

The sites of nosocomial infections,

   urinary tract
   surgical wounds
   respiratory tract
   skin (especially burns)
   blood (bacteremia)
   gastrointestinal tract
   central nervous system
         Nosocomial pathogens
       Tend to acquire antibiotic resistance factors .
       Normal flora:
         tend to become incorporated into the normal flora
          of hospital workers
         Nosocomially acquired, opportunistic infections thus
          tend to be both:
            very available for transmission to patients
            and not easily treated once infections are under way

Distribution of pathogens in HAI
   90% due to bacteria
   10% (others: virus, fungi, protozoal etc)
   Most common pathogens isolated from any HAI:
       S. aureus (13%)
       E. coli (12%)
       CoNS (11%)
       Enterococci (10%)
       Pseudomonas (9%)

Distribution of pathogens in HAI

   Most common isolated pathogens also
    depends on site of infection
       UTI (E. coli-24%)
       SSI (S. aureus-20%)
       BSI (CoNS-31%)
       LRI (S. aureus 19%, Pseudomonas 17%)

      Patient / Host risk factors:
   compromised host
   Immunodepression
   severity of illness,
   Broken skin and mucous membranes
    immuno
   Aggressive medical & therapeutic interventions
   length of stay

Organizational /Environmental risk
   Hospital environment promote spread of
    microbial pathogens
   Contaminated:
       air-conditioning systems,
       water systems,
   Staffing and physical layout of Hosp facility
    nurse-to-patient ratio,
   open beds close together.
   Presence of construction / renovation

           Iatrogenic risk factors

   Pathogens on the
       hands of medical personnel,
       Failure to follow basic infection controls
       invasive procedures (eg, intubation and
        extended ventilation, indwelling vascular lines,
        urine catheterization), and
       Misuse of antibiotics and prophylaxis.
       Acquired antibiotic resistance

          Chain of transmission
       The movement of pathogens from individual
        to individual via various routes is referred to
        as chains of transmission
       Many sick under one roof:
         The purpose of a hospital is to gather together the
          sick and injured into one place in order to efficiently
          transmit pathogens to and between them ?
       chains of transmission: childbirth fever during
        the 19th century.

       More subtle transmission:

     As a consequence of either accidental or deliberate
     disregard of established protocols designed to
     minimize transmission between patients or from
     hospital workers to patients.
    Direct person-to-person transmission between:
       an infected patient, staff member, or visitor and
        noninfected patients;
    indirect transmission through:
        equipment, supplies, and hospital procedures;
        and transmission through air are most common
        in hospitals."


   HAIs do not have a discernible sex
    predilection. However, in the
    neonatal period, low birth weight and
    male sex (male-to-female ratio is
    1.7:1) are associated with an
    increased risk of HAIs.


   Among bacterial HAIs, bacteremias
    and surgical site infections were
    more common in infants younger
    than 2 months than in older children.
    However, urinary tract infections
    (UTIs) were reported more
    frequently in children older than 5
    years than in younger children.

   Chain of transmission
       Direct contact transmission from hospital staff
        to patient and from patient-patient
       Indirect contact transmission: formites


   Three factors are important in the establishment
    of HAI:
       Microorganisms in the hospital environment
            Major reservoir of variety of pathogen
                  S. aureus (11%), Enterococcus (10%), GNB (>40%)
                  Pesudomonas (9%), Candida albican (10%)
            Source from normal flora of visitors., staff & contaminated
             hospital environment
       Compromised/weakened host
             broken skin/mucous membrane and suppressed immune


   Within hours of admission, colonies of hospital
    strains of bacteria develop in the:
       patient's skin,
       respiratory tract, and
       genitourinary tract.
   Risks factors for the invasion of colonizing
    pathogens can be categorized into 3 areas:
    iatrogenic, organizational, and patient-related.

     Major Nosocomial Infections

   UTI
       50% of all HAI
       Usually CAUTI
   Surgical & Obstetrics wound Infection
       25% of all HAI
       5-12% of all surgeries develop post-op SSI

     Major Nosocomial Infections

   Pneumonia
       12% of all HAI
       High mortality
   Blood stream Infection
       6% of all HAI
       IV Catheter implicated
   Others: Diarrhea, skin and soft tissues etc

    Major Nosocomial pathogens

   GNB: E.coli, Pseudomonas aeruginosa,
    other MDR-GNBs
   Legionella
   GPBs- CoNS, S. aureus, E. faecalis.
   Clostridium difficile
   Fungi: Candida albicans, Aspergillus

 Control of Nosocomial Infections:

The ultimate goal is to :
 improve patient care,

 reduce hospital stay;

 reduce health care related costs

 1/3 of HAI can be prevented by well run
  infection control program

               Goals of IPC

   The main objective of IPC is to prevent
    harmful pathogens from reaching
    anatomical sites where they may cause
    disease, outbreaks of such disease or
    mortality among the population
   The goals are:

                Goals of IPC

   To gather evidence, from local sources or
    from further afield, to support sound
   To develop a set of policies or guidelines
    which protect patients and health care
    workers while ensuring the best possible
    standard of care.

                Goals of IPC

   To create awareness of pathogens and
    their impact on health care workers,
    patients and the environment
   To create barriers (interventions) that
    reduce the transmission of infective
   To assist health care managers to provide
    cost-effective health without compromise
    of quality                               33
         Functions of a hospital
     epidemiology control program
   Surveillance
   Outbreak investigation,
   Education
   The health of health care employees
   The monitoring and management of institutional
    antibiotic utilization
   The development of infection-control policies
    and procedures, and new-product evaluation

      Components of a good ICP

   A trained ICP
   1 ICN ?250 beds
   A computerized surveillance system
   A system of reporting infection rates of
    hospitalized patients to practicing
    physicians and surgeons.

    Control of Nosocomial Infections-
   Reduce the number of pathogens to which
    patients are exposed by:
       Aseptic techniques for all procedures
       Careful handling of contaminated materials
       Strict and proper handwashing techniques
       Isolation rooms and wards for some
        dangerous cases


   HAI are caused by:
       viral,
       bacterial, and
       fungal pathogens.
       These pathogens should be investigated
        in all febrile patients who are admitted
        for a non -febrile illness.


   During hospital stay, patients may acquire any
       Bacterial and fungal infections are common in the
        tropics viral less common.
   Nosocomial bacterial and fungal pathogens
    usually occurs secondary to invasive supportive
    measures such as:
       intubation
       intravascular lines and
       urinary catheters.
   Fungal infections likely to arise from:
       patient's own flora; occasionally, or
       contaminated solutions (eg, those used in parenteral
             Physical Examination

   Note systemic signs and symptoms of
    infection (eg,
       fever,
       tachycardia,
       tachypnea,
       skin rash,
       general malaise),

              Physical Examination

   Source of HAIs may be suggested by:
   the instrumentation used in various procedures:
       an endotracheal tube may be associated with
        sinusitis, otitis, tracheitis and pneumonia;
       an intravascular catheter may be the source of
        phlebitis or line infection; and
       a Foley catheter may be associated with a candidal
   A detailed physical examination and review of
    systems most likely reveal the involved organs
    or systems

                   Lab Studies

   Investigation should focus on these
    abnormal areas.
   Studies should center on infections in the:
       bloodstream,
       UTI, and pneumonia,
       unless an obvious source (eg, surgical-site
        infection) is readily identified.

           Bloodstream infections
   Obtain quantitative blood cultures with samples
    from the intravenous line and peripheral vein to
    aid in differential diagnosis of line-associated
   Fungal cultures should be obtained.
   Immunocompromised patients may require
    special studies e.g:
       Nocardia
       atypical mycobacteria,
       Cytomegalovirus cytomegalovirus antigenemia

   Radiography, oxygenation, and
    hemodynamic status determination are
    required in the evaluation of nosocomial

   Examination of the sputum, endotracheal
    aspiration material, and pleural effusion
    fluid with Gram staining and culturing may
    be useful.

   Rapid diagnostic testing may be useful in
    specific cases e.g.:
       direct fluorescent antibody test for Legionella
        organisms or for organisms that cause pertussis;
       immunofluorescence tests for influenza, respiratory
        syncytial virus, which is transmitted by contact, and
       Pneumocystis jiroveci; and modified acid-fast stains
        for mycobacteria.

            Urinary tract infection
   UTIs are expected in patients who require
    indwelling urinary catheters.
   Diagnostic Challenge is to differentiate:
       colonization,
        cystitis, and
       frank pyelonephritis using urinalysis, urine Gram
        staining, and culturing.
    Early removal of the urinary catheter is always
    helpful in the treatment of catheter-associated

   A stool Gram stain should be performed to
    detect WBCs.
    Tests for C difficile toxins are useful in the
    workup for nosocomial fevers and loose
   Rotavirus spreads among susceptible
    infants during local epidemics.

        Other laboratory studies
   viral cultures from the throat and rectum if
   Acute and convalescent titers against viral
    agents can also be helpful.
   Antigen for Legionella pneumophila serotype 1
    can be detected in the urine.
   NAATs have been developed for a wide variety
    of infectious pathogens and permit rapid

             Imaging Studies

   Ultrasonography,
   CT scanning,
   MRI may be helpful in evaluating obscure-
    site infections.


   Symptomatic treatment of shock,
    hypoventilation, and other complications
    should be provided, along with the
    administration of empiric broad-spectrum
    antimicrobials, antifungals, and antivirals.

   MRSA requires treatment with different
    families of antibiotics.
           Bloodstream infections

   Line removal should be considered if the line is
    suspected in the cause of sepsis.
   Broad-spectrum antibiotics should be selected
    according to the local epidemiologic patterns of
    microbial susceptibility.
    Antifungals (eg, fluconazole, caspofungin,
    voriconazole, amphotericin B) are added to
    empiric antibiotics in some cases.
    Antivirals (eg, ganciclovir, acyclovir) could be
    used in the treatment of suspected disseminated
    viral infections.

    Change nasotracheal tubes to orotracheal
    tubes, if feasible.
   Broad-spectrum antibiotics are administered
    with guidance from the results of rapid
    examination of the sputum, endotracheal suction
    material, and bronchial lavage wash.
   Macrolide antibiotics are indicated in
   Antivirals for viral pneumonia if suspected.
         Urinary tract infection

   Indwelling catheters should be removed or
    changed if feasible.
   Empiric antibiotic and antifungal therapy is
    based on the preliminary results of
    urinalysis and urine Gram staining.

         Surgical-site infections
   These should be managed with a
    combination of surgical care and
    aggressive antibiotic therapy guided by
    the results of deep-tissue Gram staining
    and culturing.
   Fasciitis is of special concern because it is
    associated with mucoid group A
    streptococci and high morbidity and
    mortality rates.
         Surgical-site infections

   Surgical debridement is an integral part of
    management of surgical-site infections or
    super infected decubitus ulcers.

   Tissue sample should be processed using
    appropriate stains and cultures to identify
    the pathogen and its susceptibility.

             C difficile colitis:

   Management of C difficile colitis includes
    the discontinuation of the offending
    antibiotics and the use of oral
    metronidazole or vancomycin.
    Macrobiotics may be beneficial.


   Many patients with nosocomial infections
    require expert care from:
    Consultant Microbiologist,
   ICU team.
    Infectious disease specialists,
    burn care specialists, and
   surgical teams are usually involved in the
    care of complicated cases.

   Hospital based programs of Infection
    surveillance, surveillance, prevention, &
   Observe Universal precautions
   Surveillance:
       Collection, Collation, analysis and
        dissemination of data
       Outbreak investigation
     Universal precautions

   A set of procedures and guidelines
    designed to both prevent the
    infection of the health care worker
    and to break chains of transmission
    are together referred to as the
    universal precautions.
     Universal precautions
   Blood:
     In particular these procudures are
      employed to prevent the transmission of
      blood (and other body fluid)-borne
      pathogens such as HIV and hepatitis B
      virus. However, faithful following of
      these procedures will interfere with the
      trasmission of most pathogens.
     (p.

   Universal precautions

 "Universal Precautions apply to
 the following body fluids: blood,
 semen, and vaginal, tissue,
 cerebrospinal, synovial (joint
 cavity), pleural, peritoneal,
 pericardial, and amniotic fluids.

      Universal precautions
   The CDC has stated that Universal
    Precautions do not apply to feces, nasal
    secretions, sputum, sweat, tears, urine,
    and vomitus, as long as these do not
    contain visible blood.
   This is not to imply that no viruses are
    present in these fluids but rather that the
    risk of transmission is either very low or

        Universal precautions
       Generally, one:
         should avoid direct contact with patients, fomites, or,
          especially, body fluids
         should wear barriers such as gloves when contact is
          necessary or expected
         should avoid puncturing oneself with anything and therefore
          should minimize exposure to sharp instruments, especially
          body fluid-contaminated sharp instruments
         should not expose patients to the body fluids (or substances,
          e.g., "weeping dermatitis") of others, such as that of health
          care workers

    Preventing nosocomial infections

Methods of prevention of nosocomial infection (and
    breaking the chain of transmission ) include:
    observance of aseptic technique
    frequent hand washing especially between
    careful handling, cleaning, and disinfection of
    where possible use of single-use disposable
    patient isolation

Preventing nosocomial infections

   avoidance where possible of
    medical procedures that can
    lead with high probability to
    nosocomial infection
   various institutional methods
    such as air filtration within
    the hospital
Preventing nosocomial infections

   general awareness that
    prevention of nosocomial
    infection requires constant
    personal surveillance
   active oversight within the
            Surveillance systems

   NNIS (US) 1970
   Standardized protocol
       All patients (hospital wide)
       Adult /Pediatric intensive care unit (PICU)
       High Risk Nursery (HRN)
       Surgical procedures

        Outbreak investigation

   Data accumulated by ongoing surveillance
    allow the detection of Nosocomial

   A substantial role for the infection-control
    practitioner is to educate hospital personnel in
    the areas of communicable disease control,
    sterilization, disinfection, and institutional
    infection control policies.
   Blood-borne pathogen training
   Airborne-isolation-mask training and fit testing
   Handwashing training etc

         Hospital employee health

   Policies on:
       Post exposure prophylaxis of sharp injuries
       Management of exposures to communicable
       vaccination

        Antimicrobial utilization

   Nearly one half of hospitalized patients
    receive antimicrobial agents.
   Efforts should be made to optimize
    antimicrobial prophylaxis for operative

           Policy development

   The primary administrative function of the
    infection-control program is to develop,
    implement, and continually evaluate
    policies and procedures designed to
    minimize the risk of nosocomial infection


   New product evaluation
   Quality Assessment
       Monitoring data collection and analysis
       Interpretation,
       Remedial action to correct poor quality and
       Verification that remedial action have equally
        improved quality

           Medical/Legal Pitfalls

   Outbreaks of nosocomial invasive
    infections may become the subject of
    adverse publicity and legal suits against
    institutions and medical personnel.
   Many Hospitals have adopted educational
    courses that emphasize infection control,
    as well as strict enforcement and reporting
    of violation of hand-washing codes.
           Medical/Legal Pitfalls

   Many hospitals have reorganized the
    physical layout of hand-washing stations
    and have adopted patient cohorting to
    prevent the spreading of pathogens.
   They have also restricted or rotated the
    administration of many antibiotics that are
    used to combat nosocomial infections.

            Special Concerns

   Bacterial agents: Multiple-resistant
    organisms, such as vancomycin-resistant
    enterococci, glycopeptide-resistant S
    aureus, and inducible or extended-
    spectrum beta-lactamase gram-negative
    organisms, are a constant threat.

            Special Concerns

    Viral agents: The rapid spread of
    respiratory syncytial virus among pediatric
    patients during an epidemic poses a threat
    to susceptible children who require


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