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Hospital acquired infection.pptx

  2. HOSPITAL ACQUIRED INFECTION(HAI) ➜Hospital acquired infection can be defined as— ➜ the infections acquired in the hospital by a patient admitted for a reason other than the infection in context, ➜ the infection should not be present or incubating at the time of admission, and ➜ the symptoms should appear at least after 48 hours of admission.
  3. HOSPITAL ACQUIRED INFECTION(HAI) ➜This also include: ➜ Infections that are acquired in the hospital but symptoms appear after discharge ➜Occupational infections among staff of the healthcare facility (e.g. needle stick injury transmitted infections) ➜Infection in a neonate that results while passage through the birth canal (in contrast to congenital infections due to transplacental transmission, which are not HAI).
  4. BURDEN OF HAI ➜HAIs are one of the most common adverse events in the health care delivery system.  According to World Health Organization (WHO), on average at any given time 7% of patients in developed and 10% in developing countries acquire at least one HAI.  Mortality from HAI occurs in about 10% of affected patients. Treatment of these HAIs adds a huge economic burden to the hospital.
  5. Factors Affecting HAI ➜ Immune status ➜ Hospital environment ➜ Hospital organisms ➜ Diagnostic or therapeutic interventions ➜ Poor hospital administration
  6. Sources of Infection  Endogenous Source The majority of nosocomial infections are endogenous in origin, i.e. they involve patient’s own microbial flora which may invade the patient’s body during some surgical or instrumental manipulations.
  7. CONT…  Exogenous Source : are from the hospital environment, healthcare workers (HCW), or patients. Environmental sources Include inanimate objects, air, water and food in the hospital. Inanimate objects in the hospital are medical equipment (endoscopes, catheters, etc.), bedpans, surfaces contaminated by patients’ excretions, blood and body fluids  Healthcare workers May be potential carriers, harboring many organisms; which may be multidrug- resistant, e.g.nasal carriers of Methicillin-resistant Staphylococcus aureus (MRSA) Other Patients Other patients of the hospital may also be the source of infection.
  8. MICRO-ORGANISMS IMPLICATED IN HAIS  HAIs can be caused by almost any microorganism, but those which survive in the hospital environment for long periods and develop resistance to antimicrobials and disinfectants are particularly important.
  9. The ESKAPE pathogens:  They are responsible fora substantial percentage of nosocomial infections in the modern era and represent the vast majority of multidrug resistant isolates present in a hospital.
  10. The ESKAPE pathogens: ❑ Enterococcus faecium ❑Staphylococcus  aureus ❑Klebsiella pneumoniae ❑Acinetobacter  baumannii ❑Pseudomonas  aeruginosa ❑Other infections ❑ Escherichia coli ❑SARS-CoV-2 (COVID-19) ❑Nosocomially-acquired Mycobacterium tuberculosis ❑Legionella  pneumophila ❑Candida albicans ❑Clostridium difficile diarrhea
  11. Modes of Transmission  Microorganisms spread in the hospital through several modes such as contact, droplet and airborne transmissions.
  12. Major Healthcare-associated Infection Types  Though several types of HAIs exist, there are four most common types (listed below) which are often monitored to estimate the burden of HAI in a hospital. Out of these, the first three are together called as device associated infections (DAIs). 1. Catheter-associated urinary tract infection (CAUTI, 33%) 2. Central line-associated blood stream infection (CLABSI, 13%) 3. Ventilator-associated pneumonia (VAP, 15%) 4. Surgical site infection (SSI, 31%).
  13. Catheter-associated Urinary Tract Infection (CAUTI)  CAUTI is considered as the most common HAI worldwide, accounting for up to 40% of nosocomial infections. About 70–80% of healthcare–associated UTI are attributable to the presence of an indwelling urinary catheter.  Definition : Catheter-associated bacteriuria (CA-bacteriuria) has been defined as presence of significant bacteriuria in a catheterized patient.
  14. Catheter-associated Urinary Tract Infection (CAUTI)  It can be classified as: □ Catheter-associated UTI (CAUTI): Catheter Associated-bacteriuria with symptoms or signs referable to the urinary tract □ Catheter-associated asymptomatic bacteriuria (CA-ASB):  Catheter Associated-bacteriuria without symptoms or signs referable to the urinary tract
  15. MICROBIOLOGY  A broad range of bacteria can cause CAUTI, most of which are multidrug resistant.  In short-term catheterized patients: Most CAUTI are caused by the monomicrobial pathogens such as gram negative bacilli or enterococci.  E. coli is the predominant agent, although it is not as prevalent as in community-associated UTI
  16. MICROBIOLOGY Other gram-negative bacilli such as Klebsiella, Pseudomonas and Acinetobacter and gram-positive cocci such as Enterococcus account for most of the other infections.  In long-term catheterized patients, CAUTI is usually polymicrobial. In addition to the pathogens of short term catheterization, other organisms such as Proteus, Providencia and Morganella are also encountered.
  17. CENTRAL LINE ASSOCIATED BLOODSTREAM INFECTION (CRBSI)  It refers to the development of bloodstream infections (BSI) in hospitalized patients which is attributed to the presence of a central line as a source of infection and is not associated with any other secondary cause of BSI.  There is another related terminology called CLABSI (central line- associated bloodstream infection), which is strictly used only for surveillance purpose.
  18. CENTRAL LINE ASSOCIATED BLOODSTREAM INFECTION (CRBSI)  Central Line or Central Venous Catheter A central line (CL) is an intravascular device that terminates in the great vessels. It is needed for various purposes such as central venous pressure monitoring and administration of drugs, total parenteral nutrition, etc. and for hemodialysis access (hemodialysis catheters)
  19. Cont.  Central line can be classified in various ways depending up on: □ Its intended life span, e.g. temporary or short-term (<72 hrs) versus permanent or long-term (≥72 hrs) □ Its site of insertion (e.g. subclavian, femoral, internal jugular and peripheral veins) □ Its pathway from skin to great vessel (e.g. tunneled versus non- tunneled).
  20. VENTILATOR -ASSOCIATED PNEUMONIA  Ventilator-associated pneumonia (VAP) is the second most common nosocomial infection (after CAUTI) and accounts for 15–20% of the total HAIs. □ It is the most common cause of death among HAIs, with a mortality rate of up to 40% and is the primary cause of death in ICUs □ The VAP rate varies from 1.0 to 46.0 per 1000 mechanical ventilation (MV) days, depending up on the ICU facility and the hospital.
  21. Microbiology  VAP can be divided into early- and late-onset. □ Early-onset VAP: It occurs during the first 4 days of mechanical ventilation. It is caused by typical community organisms such as pneumococcus, H. influenzae, methicillin susceptible S. aureus (MSSA), etc. □ Late-onset VAP: It develops ≥5 days after mechanical ventilation and is commonly caused by typical multidrug resistant hospital pathogens—P. aeruginosa, Acinetobacter baumannii, E.coli, Klebsiella and methicillin resistant S. aureus (MRSA).
  22. Microbiology  It is associated with high attributable mortality.  Here, the source of infection may be: □ Endogenous, i.e. patient’s own oropharyngeal microbial flora transmitted to lungs by aspiration □ Exogenous, e.g. hospital environmental sources like air, water, reusable equipment, nebulized medication, etc. contaminated with environmental
  23. Surgical site infections (SSI) Surgical site infections are defined as infections that develop at the surgical site within 30 days of surgery (or within 90 days for some surgeries such as breast, cardiac and joint surgeries including implants). □ SSIs can cause significant morbidity and mortality as well as economic burden if left untreated □ SSI affects up to one third of patients who have undergone a surgical procedure, incidence is higher following abdominal operations □ In India, several studies reported SSI rate ranging from 4 to 11 per 100 surgeries.
  24. Microbiology  The type of etiological agents implicated in SSI depends upon the site of surgical procedure and the source of infection from which they are acquired. □ Endogenous source such as the patient’s own flora present on - Skin: S. aureus (the most common organism causing SSI), coagulase negative staphylococci (CoNS) - Mucosa (from opened viscus such as GIT, respiratory or genitourinary): Consists of predominantly aerobic gram-negative bacilli (E.coli, Klebsiella), grampositive cocci (Enterococcus) and anaerobes such Bacteroides, and others
  25. Microbiology Exogenous source from contact with the operative room personnel or instruments or environment: S. aureus and gram-negative bacilli including nonfermenters such as Pseudomonas and Acinetobacter.  The inoculum load and the virulence of the microorganism can determine the risk of SSI □ Inoculum of bacteria: Surgical procedures involving the sites (e.g. bowel, vagina) which are heavily colonized with bacteria have a higher risk of developing SSI as large inoculum of bacteria lodge into the wound during surgery □ Virulence of bacteria: Higher is the virulence of infecting organism, more is the risk of development of SSI.
  26. Prevention of Device-associated Infections  The majority of device-associated infections (DAIs) encountered in hospital are CAUTI, CLABSI and VAP.  Care Bundle Approach  Healthcare facilities must adhere to care bundle approach for the prevention of DAIs. □ Care bundle comprises of 3 to 5 evidence-based elements with strong clinician agreement; each of the component must be followed during the insertion or maintenance of the device □ Compliance to the care bundle is calculated as all or-none way, i.e. failure of compliance to any of the component leads to non-compliance to the whole bundle