Skip to main content
THIS PRESENTATION WAS
PRESENTED AT APOLLO INTERNATIONAL
FORUM ON INFECTION CONTROL
(AIFIC’ 2013), CHENNAI
The presentation is solely meant for Academic purpose
ROLE OF MICROBIOLOGY LABORATORY   IN
        INFECTION CONTROL
ROLE OF MICROBIOLOGIST                 IN ORGANIZING
THE LAB
    Lab results form an integral part of the complex
    decision making process and may influence upto
                 70% of medical diagnosis
    To ensure the same, the lab has to issue quality reports
    Quality of report relies on quality of clinical specimen
    submitted
    To avoid pre-analytical errors, lab has to putforth
    Specimen acceptance & Rejection criteria
    Specimen to be submitted with relevant clinical details
    Open and free communication between Clinicians &
    Microbiologist / Micro Lab essential
   Facility to access patient records preferred (healthcube)
CRITERIA FOR REJECTION                  OF    SPECIMEN

      Problem                             Action
Improper or no label   Telephone the nurse or physician , process the
                       specimen but do not issue the report

Prolonged transport    Alert the concerned staff & request a repeat
                       specimen

Improper container     Do not process & request a repeat specimen

Leaking container      Do not process & request a repeat specimen.
                       Protect the laboratory staff

Oropharyngeally        Do not report or process. Indicate the
contaminated           discrepancy & request another specimen

Obvious foreign        Alert the concerned staff & request a repeat
contamination          specimen
Problem                            Action
Duplicate specimens       Refrigerate the specimen, contact the
submitted on same day     concerned staff. Culture on request only
for same request

Specimen unsuitable for   Contact the concerned staff, indicate the
culture request e.g.,     discrepancy, request a proper specimen
anaerobe request with
aerobic transport

Quantity not sufficient   For blood: if < 5ml for an adult, inform
                          the concerned staff, request another
                          specimen. Process but add note on report
                          For other specimens: if quantity not
                          sufficient for multiple requests, call the
                          physician and determine the priority of
                          request
Specimen Collection, Transport and Processing:


      General Instructions for collection of culture specimens
   Select the correct anatomic site
   Collect the specimen using proper technique & supplies
   Package the specimen in appropriate container
   Transport promptly to the lab within 2 hrs of collection


Conditions of transport & storage of samples


      Profound influence on their usefulness
   Follow standard techniques to process samples


   Fulfill quality control requirements
   Quality Control check for media and stains
   Potency testing for antibiotic disk
   Sterility check for collection containers
   Identify causative organism to species level
    Use of automation helps speedy isolation &
    identification
                 - Automated blood culture systems
                  Automated ID & sensitivity systems


   Interpret results judiciously
   Differentiate commensals / colonizers from
    pathogens
   Perform quantitative cultures wherever required
ANTIBIOTIC SENSITIVITY TESTING
Kirby-Bauer Disk Diffusion Method – Points to remember :
    McFarlands Standard for inoculum preparation
    Depth of the media and pH
    Proper storage of antibiotic disk
    Proper placing of the disk- use template
    16 – 18 hrs of incubation
    24hrs for Staph and Entero
     - Oxacillin & Vancomycin
Selection of Anti microbial disk :
   Based on type of organism & source of isolate
   Formulate Inhouse Antibiotic Policy with reference to
international guidelines
   Use 1st line of antibiotics for out patient isolates
   2nd line to be used if resistance noted to 1st line & for
isolates from critically ill patients
   Use of E-strips for fastidious organisms / CSF isolates /
    Ciprofloxacin to Salmonella


Interpret according to International Guidelines
SMF Antibiotic Policy – Restrictive Policy
1ST & 2ND LINE ANTIBIOTICS FOLLOWED AT SMF
1st line of Antibiotics    2nd line of Antibiotics
                           (Restricted)

Penicillin-G               Amikacin
Ampicillin                 Ceftazidime
Cephalexin                 Cefotaxime
Ciprofloxacin
Ofloxacin                  Cefepime
Nitrofurantoin             Piperacillin/tazo
Nalidixic acid             Cefaperazone/sul
Gentamycin                 Imipenem
Tobramycin                 Meropenem
Azithromycin               Ertapenem
Norfloxacin
Cotrimoxazole              Aztreonam
Ofloxacin                  Vancomycin
Amoxy/clav                 Linezolid
Cefuroxime                 Teicoplanin
Cefixime                   Polymixin-B
Ceftriaxone (Salmonella)   Colistin
Clindamycin
Looking for Resistance patterns: (to guide
    antibacterial therapy)
Lab to detect common resistant mechanisms
   β-lactamase detection with Cefinase disk
   Screening for ESBL & Amp 'C' β-lactamase with
    Cefpodoxime & Cefoxitin disk
   Performing DDPT for phenotypic confirmation of ESBL
   Can be performed while testing 2nd line of antibiotics
   Oxacillin & Cefoxitin disk for Staph. isolates
   Look for Inducible Clindamycin resistance in Staph isolates
    - D Test
   Quinolone resistance in Salmonella
    - Nalidixic Acid disk as marker
    - E-strip to Ciprofloxacin
   Detection of Carbapenamase
    - Modified Hodge test
    - EDTA disk synergy test


Other methods for resistance detection
    - Automated ID & Sensitivity System (Vitek 2)
    - Molecular methods
Infection Control Critical Values (Early Warning Systems)
   Micro lab to inform ICN on a daily basis:
     - MDR GNB, MRSA, VRE
     - Sputum AFB + cases
   Microbiologist to note suspected HAI in HAI chart
   Convey to ICN for data collection in surveillance form
   Inform notifiable diseases to MRD     Chennai Corporation
     - Dengue
     - Typhoid
     - Chikungunya
     - Malaria
     - Swine flu
Role of Microbiology lab in Hospital Infection
 Control


   Identifying outbreaks early- Pseudo or true outbreak
   Conveying information to ICT & concerned ward/unit
   Charting down action plan, control measures
   Implementation through ICT
   Monitoring effectiveness of control measures
   Stock isolates from patients & suspected source
   Source identification using phenotypic & molecular
    methods
    Designing the HIC Plan in accordance with
    infrastructure & consensus of user departments
    Monitoring key infection control measures along with
    ICN
     - Hand hygiene practices
     - Standard & Isolation precautions
Compiling Culture & Sensitivity Data of hospital
  isolates
   Periodical review of culture & sensitivity patterns
   Analyze sensitivity pattern of isolates from :
     - Out patients & inpatients separately
     - Pediatric age group and adults separately
     - Resistant isolates from that of sensitive isolates
   Prepare a chart at the end of the year
   To help Clinicians
     - to know the common pathogens &
      their sensitivity pattern
     - to formulate Empirical Antibiotic of Choice
OCCUPATIONAL EXPOSURES – REPORTING
& POST EXPOSURE PROPHYLAXIS
Needle Stick Injuries – Reporting Protocol
  Reported immediately to ER Medical Officer
 Assess injury & takes action


  Enter details in Occupational Exposure Form
  Inform ICN & Microbiologist
  Source (if known) & Staff evaluation for viral
  markers
  Micro lab to process samples as Stat
  Reports conveyed to Microbiologist & ICN
  Counseling done
Post Exposure Prophylaxis:

   If source negative for viral markers - only counseling
   If source positive       consult ID & initiate PEP
   If employee vaccinated for HbsAg         assess
    AntiHBs titres
   If titre low    booster dose
   If negative          Re vaccination
   If source unknown         Anti HBs tires for Staff &
follow up
Employee Health:

   Pre employment health check up
   Staff in direct patient care tested for :
       - HBsAg
       - HIV        at entry time
       - HCV
   Vaccination details collected
    Vaccination for Hepatitis B (3 doses)      if not
    vaccinated
   Canteen & Dietary staff – Typhoid, Hepatitis A & B
   Maintenance staff - Typhoid, Hepatitis B
   Bio Medical staff - Hepatitis B
   Lab staff – Hepatitis B, Microbiology – Typhoid
   Influenza vaccine if there is outbreak
   Food handlers health check up once in a year
   Anti HBs titres checked after vaccination
Bio Medical Waste management:

   ICT to educate hospital staff on waste segregation
   Included in the induction training for House Keeping,
    Nursing & other para medical staff
   Re-education as & when required
   ICN monitors segregation on a daily basis
   HK Supervisor ensures safe transportation
   Handing over to Central facility
   Records maintained by HK Supervisor
Thank
You