1. HOSPITAL ACQUIRED INFECTIONS

2. Department of Microbiology
Prepared by- Satish Kumar Mahapatra (83) Saurabh Pathania(84) Sawan Dalal(85) Sharmista Verma(86) Shiana Singh(87) Shreya Malhan(89) Shreya Singh(90) Siddharth SK(91) Simardeep Kaur(92)
Moderator:
Dr. Mohit Bhatia
Assistant Professor
Department of Microbiology
AIIMS, Rishikesh

3. DEFINITION ( Hospital Acquired Infections= Nosocomial Infections= Healthcare Associated Infections )
CDC defines HAI as a localized or systemic condition resulting from an adverse reaction to the presence of an infectious agent(s) or its toxin(s) without any evidence of its being present or in incubation at the time of admission.
An infection is attributed as HAI if date of event occurs on or after 3rd calendar day (CL) of admission where day of admission is counted as CL 1.

4. DEFINITION Cont. It also includes
infections appearing after discharge and
occupational infections among healthcare workers.
It does not include
colonization or
inflammation resulting from tissue response to injury or non‑infectious agents.

5. Most Common Sites

6. Factors Affecting HAIs
Immune status
Hospital environment
Hospital organisms
Diagnostic or therapeutic interventions
Transfusion
Hospital administration

7. SOURCES OF INFECTIONS SOURCE Endogenous Exogenous
Patient’s own microbial flora
Exogenous
Environmental sources
Healthcare workers (carriers)
Other patients

8. Microorganisms Implicated in HAIs
The ESKAPE pathogens : capable of ‘escaping’ the biocidal action of antibiotics and represent the vast majority of multidrug resistant isolates.
Enterococcus faecium
Staphylococcus aureus
Klebsiella pneumonia
Acinetobacter baumannii
Pseudomonas aeruginosa
Enterobacter species

9. Micro-organisms contd.
Other causative agents :
Escherichia coli
Nosocomially acquired Mycobacterium tuberculosis
Legionella pneumophila
Candida albicans
Clostridium difficile diarrhea
Blood borne infections

10. Modes Of Transmission Route Contact transmission Direct
Skin to skin contact
Indirect
Contact of susceptible host with contaminated objects
Inhalational mode
Droplet transmission
Droplets of size >5µm
(<3 feet)
Org causing bacterial meningitis, diphtheria, RSV
Airborne transmission
Droplets on size <5µm
Legionella, MTB, Measles, varicella - zoster
Vector borne transmission
Via mosquitoes, flies etc.
Common vehicle transmission
Like food, water, devices, equipments

11. Types of HAIs UTIs Pneumonia Blood stream infections
Surgical site infections
Viral Respiratory Infections: Pandemic Influenza
Nosocomial Diarrhoea
Chicken Pox
Tuberculosis
Group A Streptococcal Infections
Fungal Infections
Legionellosis
Organ-transplant related Infections

12. Urinary Tract Infections (UTIs)

13. Definition :
Urinary tract infection (UTI) is defined as a disease caused by microbial invasion of1he urinary tract extending from the renal cortex of the kidney to the urethral meatus.
Nosocomial urinary tract infection is defined as a UTI acquired in any healthcare institution or more generally related to patient management within 2 CL days of admission to the hospital.

14. Introduction : It is the most common hospital-acquired infection.
It accounts for 30-40% of nosocomial infections.
Itcontributes at most 15% to the prolongation of hospital stay.
Most nosocomial UTIs are associated with preceding instrumentation or indwelling bladder catheters.

15. Source of infection :
Pathogens of the peri-urethral space from the patient’s perineum or gastrointestinal tract. (the most common pathogenesis in women)
Intraluminal contamination of urinary catheters, usually due to cross-infection by caregivers.
Pathogens from inadequately disinfected urologic equipments. (occasionally)
Pathogens from contaminated supplies. (rarely)

16. Causative agents :
The causative organisms of nosocomial infections are
Escherichia coli
Nosocomial gram-negative bacilli
Staphylococci
Enterococci
Pseudomonas
Candida etc.
Escherichia coli is the most common organism causing nosocomial UTIs as a whole.
Candida is the most common pathogen in nosocomial UTIs among patients on intensive care units. (ICUs)

17. Risk Factors : Advanced age Female gender Pregnancy
Structural and functional abnormalities
Vesico-ureteric reflux
Placement of urinary catheter
Risk Factors :

18. Factors to reduce the incidence :

19. Diagnosis : Criteria Age Signs/Symptoms Culture Symptomatic UTI 1
(SUTI 1)
Any
Fever >38O C, Suprapubic tenderness/pain, Costovertebral pain/tenderness
Urgency
Frequency
Dysuria
Urine culture ≤2 species of
microorganisms and at least one of
them ≥105 CFU/mL
Symptomatic UTI 2
(SUTI 2)
<1 year
Fever(>38°C)/hypothermia (<36°C), Apnoea, Bradycardia, Lethargy, Vomiting, Suprapubic tenderness
Asymptomatic bacteraemic UTI
any
None
Urine culture
≥105 CFU/ml with ≤2
species of microorganisms
Blood culture
≥1 matching uropathogen

20. Management :
It is directed against the pathogen identified .

21. SURGICAL SITE INFECTIONS

22. Introduction : It is the 2nd most common HAI.
Wound infections account for 15-20% of nosocomial infections.
It contributes up to 7-10 extra post-operative hospital days depending on the operative procedure and pathogen(s) involved.

23. Source of infection:
Usually the patient's endogenous or hospital-acquired skin and mucosal flora
Occasionally airborne spread of skin squames that may be shed into the wound from members of the operating-room team

24. Causative agents :
The most common pathogens in postoperative wound infections are
Staphylococcus aureus
coagulase-negative Staphylococci
enteric and anaerobic bacteria
In rapidly progressing postoperative infections manifesting within 2 CL days of a surgical procedure, the level of suspicion regarding group A streptococcal or clostridial infection should be high.

25. Risk factors : Related to the surgeons’ technical skill
The patients’ underlying conditions (e.g. diabetes mellitus, obesity)
Advanced age
Inappropriate timing of antibiotic prophylaxis
Presence of drains
Prolonged preoperative hospital stays
Shaving of operative sites by razor the day before surgery
Long duration of surgery
Infection at remote sites (e.g. untreated UTI)

26. Diagnosis :
Careful assessment the surgical site in the febrile postoperative patient
Identification of the pathogens by microscopy, culture, serology and molecular methods
Diagnosis of deeper organ-space infections or sub-phrenic abscesses requires a high index of suspicion and the use of CT or MRI

27. Management :
Drainage or surgical excision of infected or necrotic material
Antibiotic therapy aimed at the most likely or laboratory-confirmed pathogens.

28. Factors to reduce incidence :
bundling preventive measures
operating-room asepsis
Reporting surveillance results to surgeons has been associated with reductions in infection rates

29. Pneumonia

30. Introduction :
Nosocomial pneumonia is currently the 3rd most common hospital-acquired infection.
It has accounted for % of nosocomial infections.
Ventilator-associated pneumonia (VAP) occurr in 1 to >4 patients per 1000 ventilator-days.
It is responsible for a mean of 10 extra hospital days.

31. Source of infection :
Most cases of bacterial nosocomial pneumonia are caused by aspiration of endogenous or hospital-acquired oropharyngeal (and occasionally gastric) flora.
Viral pneumonias are particularly important in pediatric and immunocompromised patients.

32. Causative Organisms : Early-onset nosocomial pneumonia
manifests within first 4 days of hospitalization
mostly caused by community-acquired pathogens such as
Streptococcus pneumoniae
Haemophilus species
Late-onset pneumonias
Mostly caused by
Staphylococcus aureus
Pseudomonas aeruginosa
Enterobacter species
Klebsiella pneumoniae
Acinetobacter.
Infection is polymicrobial in about 20-40% cases.

33. Events that increase colonization by potential pathogens (e. g
Events that increase colonization by potential pathogens (e.g.， prior antimicrobial therapy, contaminated ventilator circuits or equipments, or decreased gastric acidity)
Events that facilitate aspiration of oropharyngeal contents into the lower respiratory tract (e.g., intubation, decreased levels of consciousness, or presence of a nasogastric tube)
Events that reduce host defense mechanisms in the lung and permit overgrowth of aspirated pathogens (e.g., chronic obstructive pulmonary disease, extremes of age, or upper abdominal surgery) .
Risk Factors :

34. Mortality in nosocomial pneumonia :
Associated with more deaths than infections at any other body site.
Factors affecting mortality :
Other comorbidities,
Inadequate antibiotic treatment,
Involvement of specific pathogens (particularly Pseudomonas aeruginosa or Acinetobacter)
Surveillance and accurate diagnosis of pneumonia have been problematic in hospitals because many patients, especially those in the ICUs, have abnormal chest roentgenographs, fever, and leukocytosis potentially attributable to multiple causes.

35. Diagnosis :
Clinical criteria for diagnosis have high sensitivity but relatively low specificity.
Clinically selected patients undergo bronchoscopic or nonbronchoscopic procedures that yield lower respiratory tract samples protected from upper-tract contamination.
Quantitative culture of such specimens have diagnostic sensitivities of around 80%.
Clinical criteria includes fever, leucocytosis, development of purulent secretions, new or changing radiographic infiltrates, changes in oxygen requirement or ventilator settings.

36. Criteria : Criteria Respiratory cultures/Non-culture tests Criterion 1
Quantitative or semiquantitative respiratory cultures
(Purulent or Non-purulent)
Endotracheal aspirate, ≥105 CFU/ml
Bronchoalveolar lavage, ≥104 CFU/ml
Lung tissue, ≥104 CFU/g
Protected specimen brush ≥103 CFU/ml
Criterion 2
Culture without sufficient growth to meet criterion 1: Purulent respiratory secretions from any one of the following specimens Sputum, Endotracheal aspirate, Bronchoalveolar lavage, Lung tissue,
Protected specimen brush
Criterion 3
Any one of the following Organism identified from pleural fluid test positive for legionella, Respiratory secretions positive for influenza virus, respiratory syncytial virus, adenovirus, parainfluenza virus, rhinovirus, human metapneumovirus, coronavirus species

37. Management : It is directed against the identified causative agent.
The appropriate duration of therapy for nosocomial pneumonia is around 8 days with a longer duration ( around 15 days ) when the pathogen is Acinetobacter or Pseudomonas aeruginosa.

38. Factors to reduce incidence :
Frequent testing of readiness for extubation,
Remediation of risk factors in patient care (e.g., minimizing aspiration-prone supine positioning)
Aseptic care of respirator equipmentSelective decontamination of the oropharynx and gut with nonabsorbable antimicrobial agents and/or use of short-course postintubation systemic antibiotics
Placement of endotracheal tubes that provide channels for subglottic drainage of secretions
Non-invasive mechanical ventilation whenever possible
coated endotracheal tubes Use of silver
Factors to reduce incidence :

39. Blood Sream Infection

40. Introduction :
Nosocomial blood stream infections are the 4th common cause of HAIs.
Intravascular device-related bacteremias cause 10-15% of nosocomial infections and central vascular catheters (CVCs) account for most of these bloodstream infections.
It accounts for an excess mean length of hospital stay of 12 days.
One-third to one-half of these cases occur in ICUs.

41. The cutaneous microflora of the insertion site, with
Source of infection
The cutaneous microflora of the insertion site, with
Extraluminally to the catheter tip usually during the 1st week after insertion
Contamination of the hubs of CVCs or of the ports of "needle-less" systems may lead to intraluminal infection over longer periods, particularly with surgically implanted or cuffed catheters.
Intrinsic (during the manufacturing process) or extrinsic (on-site in a health care facility) contamination of infusate (rarely) most common cause of epidemic device-related bloodstream infection

42. Causative organisms : coagulase-negative staphylococci,
Staphylococcus aureus,
Enterococci,
nosocomial gram-negative bacilli,
Candida.

43. Risk Factors : Age (<1 year and >60 years) Malnutrition
Low immunity
Severe underlying diseases
Loss of skin integrity (burn or bed sore)
Prolonged hospital stay, especially in ICUs
Presence of intravascular catheters.
Risk Factors :

44. Diagnosis : Suspected on the basis of
the appearance of the catheter site or
the presence of fever or bacteremia without another source in patients with vascular catheters.
Confirmed
by the recovery of the same species of microorganism from peripheral-blood cultures (preferably two samples drawn from peripheral veins by separate venipunctures)
from semiquantitative or quantitative cultures of the vascular catheter tip.

45. Diagnosis cont. Less commonly used diagnostic measures include
differential (faster) time to positivity (>2 h) for blood drawn through the vascular access device than for a sample from a peripheral vein and
difference in quantitative cultures (a threefold or greater "step- up") for blood samples drawn simultaneously from a peripheral vein and from a CVC, which should show the step-up if infected.
When infusion-related sepsis is considered (e.g., because of the abrupt onset of fever or shock temporally related to infusion therapy), a sample of the infusate or blood-product should be retained for culture.

46. Criteria Criterion Age Signs/Symptoms Pathogen Comments LCBI-1 Any
None
Recognised pathogens
All elements of criteria must be met within the infection window period (IWP).
MBI-LCBI-1
Must be an intestinal pathogen
LCBI-2
>1 year
Fever (>38o C)
Chills
Hypotension
Common commensals
MBI-LCBI-2
-do-
Only Viridans group streptococci
LCBI-3
</=1 year
Apnoea
Bradycardia
Hypothermia
MBI-LCBI-3
LCBI= Laboratory Confirmed Blood stream Infection
MBI-LCBI= Mucosal Barrier Injury-Laboratory Confirmed Blood stream Infection
MBI-LCBI is applied for hematopoietic stem cell recipients and immunocompromised individuals.

47. Management :
Therapy for vascular access-related infection is directed at the pathogen recovered from the blood and/or infected site.
Various guidelines recommend catheter removal in most cases of bacteremia or fungemia due to nontunneled CVCs.
Antibiotic lock technique can also be used in addition to systemic antimicrobial therapy to salvage a potentially infected catheter.

48. Factors to reduce incidence :
Chlorhexidine-impregnated patch at the skin-catheter junction,
Daily bathing of ICU patients with chlorhexidine and water,
Application of semitransparent access-site dressings (for ease of site inspection),
Avoidance of the femoral site for catheterization because of a higher risk of infection (most likely related to the density of the skin flora)
Rotation of peripheral catheters to a new site at specified intervals (e.g., every hour), which may be facilitated by use of an IV therapy team,
Application of aseptic technique when accessing pressure transducers or other vascular ports
Factors to reduce incidence :

49. Standard (routine) precautions Specific precautions
Prevention of HAI
Standard (routine) precautions
Specific precautions

50. Standard(routine )precautions
Standard precautions are a set of infection control practices used to prevent transmission of diseases that can be acquired by contact with blood, body fluids, non-intact skin (including rashes), and mucous membranes.
These measures should be followed when providing care to:
• All individuals, whether or not they appear infectious/ symptomatic or not.
• All specimens (blood or body fluids) whether they appear infectious or not.
• All needles and sharps whether they appear infectious or not.

51. Personal protective equipments
Standard precautions
Hand hygiene
Personal protective equipments

52. Hand hygiene
Most important measure to avoid the transmission of harmful microbes and prevent healthcare-associated infections.
2 types i)Hand rub
ii)Hand wash
Hand Rub
() Alcohol based(70-80% ethyl alcohol) and chlorhexidine(2-4%) based
() Duration of contact seconds
() Advantage-after a period of contact it gets evaporated of its own,drying of hands not required separately
() Indication-routinely in wards or ICU;in all moments requiring hand hygiene ,except when the hands are visibly dirty or soiled, when it is ineffective

53. Hand Wash Antimicrobial soaps(liquid, gel,bars)
Even ordinary soaps can be used
Duration of contact seconds
Indications
• When the hands are visibly soiled with blood, excreta, pus, etc.
• Before and after eating
• After going to toilet
• Before and after shift of the duty

56. Personal Protective Equipments

57. Specific Protection Airborne Precautions Droplet Precautions
Contact Precautions

60. Precautions in patients having MDROs
The increased occurrence of multidrug resistant organisms (MDROs) is a major medical concern. The spread of MDROs such as multidrug resistant MRSA is usually by transient carriage on the hands of healthcare workers. The following precautions are required for the prevention of spread of epidemic of MRSA:
• Minimize ward transfers of staff and patients
• Ensure early detection of cases, especially if admitted from another hospital; screening of high risk patients may be considered
• Isolate infected or colonized patients in a single room, isolation until or cohorting in a larger ward
• Reinforce hand washing by staff after contact with infected or colonized patients
• Use gloves, gown or apron for handling MRSA contaminated materials, or infected or colonized patients
• Consider treating nasal carriers with mupirocin
• Consider daily wash or bath by antiseptic detergents for carriers or infected patients

61. Hospital infection control committee
A forum for multidisciplinary input and cooperation, and information sharing, required for hospital infection control and prevention
Terms of Reference of HICC
HAI surveillance: Maintains surveillance of hospital acquired infections. The four key parameters used for HAI surveillance are as follows:
I. CA-UTI (Catheter associated urinary tract infection)
2. CLABSI ( Central line associated bloodstream infection)
3. VAP (Ventilator associated pneumonia)
4. SSI (Surgical site infections)

62. Developing a system: identify,report,analyse,investigate,control
Antibiotic usage: policies, monitoring, advicing, recommends remedy
Policies : time to time reviews and updates of policies and procedures
Staff health
Outbreak management
Other depts.
Reviews
HICC settings

63. References :
Sastry A, K S. Hospital Acquired Infections. In: Sastry A, K S, Janagond A, ed. by. Essentials of MEDICAL MICROBIOLOGY. 1st ed. New Delhi: Jaypee Brothers Medical Publishers (P) Ltd; p
Weinstein R. Infections Acquired in Health Care Facilities. In: Kasper D, Faucy A, Hauser S, Longo D, Jameson J, Loscalzo J, ed. by. HARRISON'S PRINCIPLES OF INTERNAL MEDICINE. 19th ed. Mc Graw Hill Education; p
Gupta R, Sharma S, Parwez, Saxena S. Changing panorama for surveillance of device-associated healthcare infections: Challenges faced in implementation of current guidelines. Indian J Med Microbiol 2018;36:18-25