safety measures to be followed during handling of clinical specimens

1. Safety
measures in
clinical
laboratory
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2. Standard precautions
 In 1987, the CDC (Centre for Disease
Control) published guidelines known as
Universal Precautions, to reduce the risk of
HBV transmission in clinical laboratories
and blood banks. In 1996, these safety
recommendations became known as
Standard Precautions.
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3.  Do not eat, drink, smoke, or apply cosmetics (including lip balm).
 Do not insert or remove contact lenses.
 Do not bite nails or chew on pens.
 Do not mouth-pipette.
 Limit access to the laboratory to trained personnel only.
 Assume all patients are infectious to prevent skin and mucous membrane
exposure, including wearing gloves at all times and masks, goggles, gowns, or
aprons if there is a risk of splashes or droplet formation.
 Thoroughly wash hands and other skin surfaces after gloves are removed and
immediately after any contamination.
 Take special care to avoid injuries with sharp objects such as needles and
scalpels.
 The CDC's Standard Precautions should be followed for handling blood and
body fluids, including all secretions and excretions (e.g., serum, semen, all
sterile body fluids, saliva from dental procedures, and vaginal secretions)
submitted to the microbiology laboratory.
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4. Classification of infective
microorganisms by risk group
 As a laboratory worker is exposed to
many infectious microorganisms, the
knowledge of pathogenic property of
each microorganism is essential. This will
help to follow specific safety precaution in
handling such microorganisms.
 WHO has classified infective
microorganisms into four groups.
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5.  They are classified according to their
pathogenic potential, route of
transmission, consequence if the agent
escape from the laboratory and possible
hazard to the individual and public.
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6.  Risk group 1: No or very low individual and
community are at risk from such kind of
organisms. A microorganism that is unlikely
to cause human or animal disease. Simple
precaution should be taken to protect
from such organisms.
 Examples: Food spoilage bacteria,
common molds, yeasts.
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7.  Risk group 2: Moderate risk to lab workers, low
community risk. Organisms that may cause
human disease and may be a hazard to
laboratory workers but are unlikely to spread
to the community. Laboratory exposures may
cause serious infection, but effective
treatment and preventive measures are
available (vaccine and chemotherapy).
 Examples: Staphylococci, streptococci,
adenovirus, poliovirus, Toxoplasma,
Leishmania, enterobacteria.
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8.  Risk group 3: High individual risk, low
community risk. This group contains
organism that presents a high risk to the
laboratory worker but a low risk to the
community if they escape from the
laboratory. Effective treatment and
preventive measures are available.
 Examples: Mycobacterium tuberculosis,
Salmonella Typhi, Brucella, Histoplasma,
HIV.
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9.  Risk group 4: High individual and community
risk. The organism in this group cause severe
human disease and pose a serious risk to
laboratory workers. Disease is quickly
transmitted from one person to next and pose
a high risk of spread in the community.
Effective treatment and preventive measures
are not usually available.
 Examples: Virus of hemorrhagic fevers
including Marburg, Lassa and EBOLA.
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10. Classification of
laboratories/containment
levels:
 According to the organism handled and
processed from the above risk groups,
different laboratories require different
conditions to work with the infectious
organisms.
 There are four biosafety levels of
laboratory
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11. a. Biosafety level 1 (containment level 1)
b. Biosafety level 2 (containment level 2)
c. Biosafety level 3 (containment level 3)
d. Biosafety level 4 (containment level
4/maximum containment laboratory)
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12. a. Biosafety level 1: Normally harmless
microorganism from risk group 1 require general
setting of the laboratory.
b. Biosafety level 2: Most pathogens encountered in
clinical laboratories fall into hazard group 2 and
must be handled in cantainment level 2.
 Safety code of practice should be followed. There
should be good sanitary facility, should be
cleaned regularly and protective equipment
should be worn while working.
 An autoclave for sterilization of waste must be
available.
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13. c. Biosafety level 3: This type of laboratory is
required for working with risk group 3
organisms.
 There should be a HEPA filter and the
laboratory should have access to authorized
person only.
 As the laboratory handle infectious agent, it
should maintain good ventilation system for
managing aerosols.
 Work should be done with high precaution to
avoid laboratory escape of microorganisms.
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14. d. Biosafety level 4: This type of laboratory is
mainly designed to work with virus in Risk
group 4.
 As risk group 4 microorganisms are difficult to
cure and no medicine is available, their
spread in the community may cause great
human casulties.
 To avoid laboratory escape of such viruses,
the laboratory are build in separate buildings
with access to government official.
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15.  What comes in the laboratory and what
goes out are tightly regulated.
 Air passing out of the laboratory are
filtered twice and all effluents and
laboratory washings are decontaminated
before discharge into sewage system.
 One has to take shower before and after
coming out of the laboratory.
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16. Decontamination and safe
disposal of contaminated
materials
a. Autoclaving (sterilization)
b. Boiling (disinfection)
c. Incineration
d. Use of chemical disinfectant
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17. a. Autoclaving
 When performed correctly, autoclaving is
the most effective method of
decontamination because it is capable
of sterilizing infectious waste, i.e.,
destroying all bacteria, bacterial spores,
viruses, fungi and protozoa.
 A temperature of 121⁰C and holding time
of 15 minutes is used.
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18.  Materials and objects to be sterilized
should be loosely packed in the chamber
so that steam can circulate freely and air
can be removed easily.
 Plastic bags should be opened or steam
will not penetrate to their contents.
Materials suspected of 'Prions' require high
temperature and holding time.
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19. b. Boiling
 Heating in boiling water at 100⁰C for 20
minutes at normal altitude is sufficient to kill all
non-sporing bacteria, some bacterial spores,
fungi, protozoa, and all viruses including
hepatitis viruses and HIV.
 When autoclaving is not possible, reusable
syringes, needles, specimen containers and
contaminated glassware and plasticware
can be decontaminated by boiling in water
for 10-20 minutes.
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20. c. Incineration
 Incineration is a high-temperature dry
oxidation process that reduces organic
and combustible waste to inorganic,
incombustible matter and results in a very
significant reduction of waste volume and
weight.
 This process is usually selected to treat
wastes that cannot be recycled, reused
or disposed off in a landfill site.
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21.  Incinerators can range from extremely
sophisticated, high-temperature operating
unit to vary basic combustion unit that work
at low temperature.
 All types of incinerator, if operated properly,
eliminate pathogens from waste and reduce
the waste to ashes. Incinerators designed
especially for treatment of health-care waste
should operate at temperatures between 900
to 1200⁰C.
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22. d. Use of chemical disinfectant
1. Phenolics
2. Chlorine-releasing products
3. Aldehydes
4. Alcohols
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23. 1. Phenolics
 Phenolic disinfectants should be used at 2-5%
concentration (v/v).
 Dilutions should not be kept for more than 24
hours.
 Phenolics are non-corrosive and used for wiping
bench, surfaces and floors, discard jars, etc.
 They do not effectively kill spores and non-lipid
viruses.
 They are active against non-sporing bacteria
including mycobacteria.
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24. 2. Chlorine-releasing products
 These compounds give-off free chlorine in solution,
which is active against Gram positive, Gram
negative, HIV and hepatitis viruses. They are
corrosive to metal. Sodium hypochlorite, calcium
hypochlorite etc are used.
 0.1% (1g/L)=for routine disinfection of working
surfaces.
 1% (10g/L)=for treating spillages of infectious
material
 0.25% (25g/L)=for discard containers, pipettes, jars
etc.
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25.  Chlorine releasing products are used in
discard containers and for treating
spillages of blood. Chlorine products are
less effective for mycobacteria than
phenolics.
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26. 3. Aldehydes
 Formaldehyde generated by heating
formalin or paraformaldehyde is used for
decontaminating safety cabinet and may
also be used for decontamination of
different hospital premises.
 Formalin solution is toxic with an irritating
vapour, and may cause sensitivity
reactions. It is also a probable carcinogen
and should be used in a well ventilated
laboratory.
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27.  Gluteraldehyde is an excellent
disinfectant and is used for discarded jars,
surfaces, and for metals like autoclave,
centrifuge, where corrosive chlorine
products cannot be used. It rapidly
inactivates bacteria and viruses including
HIV and HBV.
 It is also active against mycobacteria.
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28. 4. Alcohols
 Ethanol and propanol at 70-80% v/v
concentration in water are useful for
disinfecting skin and surfaces.
 Alcohols are highly active against
mycobacteria, non-sporing Gram positive,
Gram negative bacteria, enveloped virus
including HIV, Hepatitis B and C viruses, which
are inactivated by alcohol treatment.
 Alcohols do not effectively act against non-
lipid (naked) viruses and bacterial spores.
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29. Biosafety precaution during
transportation of hazardous
materials
 In March 2005 the requirements for
packaging and shipping biologic material
were significantly revised in response to
the international community's desire to
ensure safe and trouble-free shipment of
infectious material.
 Packaging and shipping biological
materials should be safe and trouble-free.
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30.  Triple packaging for both diagnostic/clinical
or infectious substance in a pouch or a rigid
bottle should be done.
 Infectious specimens or isolates should be
wrapped with absorbent material and
placed within a plastic biohazard bag, called
a primary receptacle.
 The primary receptacle is then inserted into a
secondary container
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31.  After the secondary container is capped, it is
placed in an outer tertiary container
constructed of fibreboard.
 Shippers should note that some carriers have
additional requirements for coolant materials
such as ice, dry ice, or liquid nitrogen.
 Because of the distinction of risks between
infectious substances and diagnostic
specimens, there are variations to the
packaging, labeling and documentation
requirements.
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32. Basic triple packaging system
The system consists of three layers as follows;
1. Primary receptacle.
 A labelled primary watertight, leak-proof
receptacle containing the specimen.
 The receptacle is wrapped in enough
absorbent material to absorb all fluid in
case of breakage.
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33. 2. Secondary receptacle.
 A second durable, watertight, leak-proof
receptacle to enclose and protect the
primary receptacle(s).
 Several wrapped primary receptacles may
be placed in one secondary receptacle.
 Sufficient additional absorbent material must
be used to cushion multiple primary
receptacles.
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34. 3. Outer shipping package.
 The secondary receptacle is placed in an
outer shipping package which protects it and
its contents from outside influences such as
physical damage and water while in transit.
 Specimen data forms, letters and other types
of information that identify or describe the
specimen and also identify the shipper and
receiver should be taped to the outside of the
secondary receptacle.
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36. Thank you!!!
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