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									   Infection Control Practice in Laboratory

● Routes      of Lab Acquired Infection
  1-Oral - eating, drinking, and smoking. Mouth pipetting, transfer microorganisms
    to the mouth by contaminated fingers or articles

 2. Skin - injuries by needles, sharp instruments, or glass. Cuts and scratches

 3. Conjunctiva - splashes of infectious material into the eye, transfer of
    microorganisms to eyes by contaminated fingers.

 4. Lungs - inhalation of airborne microorganisms

● Microbiology cultures offer the opportunity for infection during sub culturing of
  plates or blood culture bottles, as well as mixing, vortexing, and centrifuging
  infectious material.

● Lab-   Acquired Infectious Agents
- Hepatitis A, B ,C virus [ MAJORITY]         - Influenza, Adeno, and Mumps

- Polio and coxsackie viruses                 - HIV / Rabies / Arboviruses [ RARE]

- Shigella /Salmonella spp.                   - N. meningitides

- M. tuberculosis                             - Brucella spp/ B. anthracis

- Clostridium botulinum                      - Yersinia pestis

- Leptospira spp.                            - Histoplasma /

- Coccidioides immitis

Page 1                                                            Dr.Gihan EL-Batouti
● Containment defines the safe methods for controlling infectious agents where they
  are being handled.

● Purpose:

  To reduce exposure to, and to prevent the escape into the environment of,
  potentially hazardous agents.

● Elements: they are 3

1-Laboratory practice and techniques

2- Safety equipment

3- Facility design

1. Laboratory Practice and Techniques
  Laboratory Biosafety Plan
  A documented plans that:

  a- Identifies potential hazards

  b- Specifies practices and procedures

  c- Includes required equipment and facilities designed to eliminate or to minimize
      employee exposure to infectious agents or hazardous material.

   Important to:

  a- Adhere strictly to standard microbiological and infection prevention and control
     practice and procedures.

 b- Ensure that lab personnel are properly trained in lab techniques, safety
    procedures, and hazards associated with handling potentially infectious agents.

2. Safety Equipment
 - Provides the primary barriers between the infectious agent and the worker.

 - It includes Biological safety cabinets [preferably Class II], safety centrifuge cups and
   PPE that must be used whenever:

 1. Procedures with a potential for creating infectious aerosols or splashes.

Page 2                                                             Dr.Gihan EL-Batouti
2. High concentrations or large volumes of infectious agents are used.

                         Aerosol Production
● These    include:
 a- centrifuging / grinding/ blending

 b- Vigorous shaking or mixing [magnetic stirrer]

 c- Opening containers of infectious materials [test tubes /culture tubes/ vials /


 d- Pipetting

 e- Syringe and needle

 f- Freeze-dried samples

 g- Vacuum-sealed ampoules

 h- Heated inoculating loop

 i- Separating funnel

● Minimizing Aerosol           Production
1. Use BSC or fume hood.

2. Keep tubes screw capped when vortexing or centrifuging.

3. Allow aerosols to settle for 1-5 minutes before opening centrifuge blender, or tubes
   that have been mixed.

4. Place a cloth soaked with disinfectant over the work surface to deactivate possible
   spills or droplets of biohazard agents.

5. Reconstitute or dilute contents of an ampoule slowly.

6. When mixing two solutions, discharge the secondary fluid down the side of the
   container as close as possible to the surface of the primary one.

7. Allow inoculating loop or needle to cool before touching biological specimen

8. Wrap the relevant item with disinfectant – soaked gauze when:

 - Removing needles from the rubber stoppers of the test tubes or vials.

 - Breaking the cap on an ampoule.

 - Removing stoppers or plugs from tubes.

Page 3                                                            Dr.Gihan EL-Batouti
 - Expelling air or surplus solution from the syringe.

A- Mix a solution by flushing with pipette or syringe.

B- Use a syringe as a substitution for mechanical pipetting devices when transferring
   infectious fluids

Design Issues for Laboratories
- Dedicated toilets for the patients should be located next to the receiving area.

- A separate room should be affiliated to the lab for reprocessing glassware,
  instruments and chemical disposal. An autoclave should be present in this area.

Laboratory facilities
1- Provide lockable doors for labs that hold restricted microbiologic agents.

2- The laboratory is designed so that it can be easily cleaned, including furniture. Do
   not place carpets and rugs in labs.

3- Bench tops should be impervious to water, resistant to moderate heat, organic
   solvents, acids, alkalis, and chemicals used to decontaminate the work surfaces and

4- Accessible spaces between benches, cabinets, and equipment for cleaning.

5- Chairs and other furniture should be covered with a non-fabric material that can be
   easily wiped and decontaminated.

6- Adequate Storage space.

Page 4                                                            Dr.Gihan EL-Batouti
Cleaning and Decontamination
A- Decontaminate all potentially contaminated equipment with appropriate
   disinfectant. [Interiors of incubators, hot air ovens, autoclaves refrigerators ].

   - ALCOHOL:      [antiseptic/disinfectant]

  - CHLORINE:      [in presence of organic matter]

  - PHENOLS:        [inactivated by wood /plastic/rubber]

B- Equipment must be completely decontaminated prior to being sent for routine
   maintenance or repair.

C- Use closed leak- proof containers to transport instruments that are to be sterilized
   at a site away from the lab.

Automated equipment
1) The probes should be shielded to avoid splashing. Effluent should be collected in
    closed bottles or discharged at least 25 cm into the waste plumbing system.

2) The effluents from automatic apparatus are unlikely to be very hazardous since
   microorganisms are likely to have encountered to chemicals on their way through
   the machine

1) Perform adequate decontamination before washing or disposing waste [Media,
   reagents, samples, cultures] by autoclaving or soaking in chlorine bleach solution for
   10-20 min. before disposal in the biohazard waste bags to be sent for incineration.

2) Provide discard jars for contaminated glassware, pipettes and their tips

Discard Jars
a- Should be robust and autoclavable.

b- Glass jars should not be used because they are easily broken. Polypropylene

  Beakers or wide-mouth screw capped jars are preferred.

c- They are left open on the bench but are closed at the end of the working session.

d- It is important that discard jars are filled frequently with chlorine solution [changed

Page 5                                                             Dr.Gihan EL-Batouti
e- Should be washed with hot water before re-use. It is better to autoclave the jar
   before washing.

Basic spill kit should be available including:
- Disinfectant [diluted chlorine bleach]

- Package of disposable paper towels/      sponges

- LATEX disposable gloves

- Forceps or dust bin for broken glass

Serious spillages
a- Cultures dropping on the floor and breaking, resulting in a considerable amount of
   aerosol dispersal.

b- Lab workers should not bend down to inspect the damage.

c- Instead, all people in the room should hold their breath and leave.

d- Any possibly contaminated clothing should be removed, or the affected area should
   be sponged with a disinfectant-detergent.

e- Hypochlorite should not be used because it will bleach the fabric.

Pipetting Precautions:
1- Avoid rapid mixing of liquids by alternate suction and expulsion.

2- Do not forcibly expel material from a pipette.

3- Do not bubble air through liquids with a pipette.

4- Prefer pipettes that do not require expulsion of last drop of liquid.

5- Drop material having pathogenic organisms as close as possible to the fluid or agar

6- Do not place contaminated pipettes on the bench top. Place contaminated pipettes
   in a container having suitable disinfectant [ prepared daily] for complete

7- Broken and chipped pipettes should be discarded.

8- Use plastic disposable ones.

Page 6                                                             Dr.Gihan EL-Batouti
General Biosafety Practices
1- Wear coats and PPE.

2- Keep nails short and trimmed. Do not wear any jewelers while on duty.

3- Long hair should be bound back neatly away from shoulders

4- Keep fingers, pencils, bacteriological loops etc. out of your mouth.

5- Mechanical pipetting, not mouth pipetting, must be used for the manipulation of all
   liquids in the laboratory

6- Eating, drinking, smoking is prohibited in the laboratory.

7- Do not drink from laboratory glassware.

8- Do not store food in lab refrigerators.

9- There should be a separate designated area.

10-Do not lick labels with tongue (use tap water).

11-Any accidents as skin punctures or splashes to the face, must be reported
   immediately. As a rule, affected sites must be cleaned or washed thoroughly with
   running water.

12-Immunize the laboratory workers against vaccine-preventable diseases such as
   hepatitis B, meningococcal meningitis, rabies, etc.

13-Keep doors closed

14-Keep doors locked when vacant

15-Allow entry of authorized personnel only

16-Limit access to the lab during procedures involving biohazardous agents

17-As far as possible children and pregnant women visitors should not enter the
   microbiological laboratories.

Page 7                                                           Dr.Gihan EL-Batouti
a- Infectious material may be dispersed by a centrifuge through broken or opened

b- Take care that the centrifuge tubes are not cracked.

c- Tubes should not be more than three-quarters full, especially if angle centrifuges
   are used.

d- Tubes should be capped.

e- Buckets should be sealed and balanced carefully to avoid vibration which may lead
   to breakage

Transfer of Specimen to the Lab
● It is Responsibility of Lab technician

● Precautions:

 1. Wear gloves.

 2. Avoid contact with the content of the container.

 3. Use secondary leak-proof containers or bags when transporting samples and

 4. Label containers indicating contents. Use biohazard label.

 5. Place specimens in special holders or boxes

Handling of Specimen
1. Wash hands before collecting each specimen and wear gloves.

2 . Cultures, tissues, specimens, body fluids are placed in screw capped leakage proof
    labeled containers during collection, handling, processing, storage, transport, or

3. Follow aseptic techniques when collecting samples. [Sharps safety]

Page 8                                                           Dr.Gihan EL-Batouti
4. Keep the outside of the container clean. Wipe gently with disinfectant if

 5. Samples should not be collected inside the lab.

Page 9                                                           Dr.Gihan EL-Batouti

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