biohazard medlab
TRANSCRIPT
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Biological Hazards in Medical
and Research Laboratories
October, 2010
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This module gives an overview of how bacteria and virusescan cause injury, illness, or even death to medical laboratory
workers.
What You Will Learn
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Bacteria Exposure
The Centers for Disease Control (CDC)data indicates these bacteria have a high
exposure potential in labs:
Mycobacterium tuberculosis Bacillus anthracis
Bordetella pertussis
Brucella sp. Neisseria meningitis
Many labs also culture other types of dangerous bacteria.
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Bacteria Exposure
In the lab bacteria can become airborne by:
Removing vacutainer caps
Manipulation of cultures
Centrifuge, test tube fractures/cracks
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Bacteria Exposure - Tuberculosis
Present in sputum, gastric fluid, CSF, urine and
lesions of persons with active disease (not latent)
Bacilli survive in heat-fixed smears
Transmitted via airborne droplet from an infected
persons respiration, in preparation of frozen sections
and in preparation of liquid cultures.
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Tuberculosis
90% of all persons infected with TB will never develop active TB
TB infected or exposed people are NOT contagious
Only contagious if they have ACTIVE TB disease
Source: CDC
- Surveillance: PPD skin testing or blood assay based on laboratorys risk
level.
- Prior vaccination with BCG not considered when interpreting PPD skin test.It is impossible to differentiate between BCG mediated response and latent
infection.
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Bacteria Exposure - Anthrax
Present in blood, skin lesion exudate,CSF, pleural fluid, rarely in urine and
feces
Aerosolized during handling
Direct and indirect contact of intact or
broken skin with cultures and
contaminated lab surfaces
- Requires prompt diagnosis- Vaccine is available
Gram-positive anthrax
bacteria (purple rods) in
cerebrospinal fluid sample
http://en.wikipedia.org/wiki/File:Gram_Stain_Anthrax.jpg -
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An Anthrax Infection Incident
Lab in Texas was processing environmental samples
for anthrax in support of CDC bioterrorism
investigation.
A worker had cut his face shaving. The next day, he
was moving vials containing aliquots of confirmed
anthrax from the biological safety cabinet to a freezer
in the next room. The worker did not use gloves. He
washed his hands after handling the vials.
Within one day, his facial cut worsened on day 5, he
was admitted to the hospital and treated for cutaneous
anthrax.
Most likely source was the surface of the vials. No workers in the lab were immunized against anthrax.
From April 5, 2002 MMWR (Morbidity and Mortality Weekly Report from CDC)
Skin anthrax-source: CDC
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Pertussis (whooping cough):
Hazard is aerosol generation during
culture manipulation
Incidence on the rise see the latest
report
May be mild or classic in adults
Most lab cases in research labs
Source: CDC
- A pertussis vaccine is now
available for adults
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5926a5.htm?s_cid=mm5926a5_e%0d%0ahttp://www.cdc.gov/mmwr/preview/mmwrhtml/mm5926a5.htm?s_cid=mm5926a5_e%0d%0ahttp://www.cdc.gov/mmwr/preview/mmwrhtml/rr5517a1.htmhttp://www.cdc.gov/mmwr/preview/mmwrhtml/rr5517a1.htmhttp://www.cdc.gov/mmwr/preview/mmwrhtml/mm5926a5.htm?s_cid=mm5926a5_e%0d%0ahttp://www.cdc.gov/mmwr/preview/mmwrhtml/mm5926a5.htm?s_cid=mm5926a5_e%0d%0a -
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Brucellosis
One of the most commonly
reported lab-associatedbacterial infection
Present in blood, CSF, semen
and occasionally urine ofinfected persons
Transmitted through aerosols
generating procedures
- No vaccine for humans,treatment is with antibiotics
Reported cases of brucellosis - 2007
Source: CDC
CDC recommendations for brucellosis lab exposure
http://www.azdhs.gov/phs/oids/vector/brucella/pdf/CDC%20RECOMMENDATIONS%20FOR%20BRUCELLA%20LABORATORY%20EXPOSURES.pdfhttp://www.azdhs.gov/phs/oids/vector/brucella/pdf/CDC%20RECOMMENDATIONS%20FOR%20BRUCELLA%20LABORATORY%20EXPOSURES.pdf -
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N. Meningitis
Present in pharyngeal exudates,
synovial fluid, urine, feces, CSF
Aerosols from laboratory procedures
on isolates
Vaccine is available andrecommended for lab workers
routinely exposed.
Post-exposure antibiotics
o Rifampin or ciprofloxacin given orally; or
o Ceftriaxone given IM
The use of post-exposure antibiotics have prevented outbreaks.
Link to CDC webpage on meningitis
N. Meningitis bacteria
http://www.cdc.gov/meningitis/index.htmlhttp://www.cdc.gov/meningitis/index.html -
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Meningitis Exposure Incidents
Two microbiologists contracted meningitis, both died.
#1: 3 days before symptoms, the patient had prepared a gram stain
from the blood culture of a patient who was subsequently shown to
have meningococcal disease. The microbiologist had also handledand sub-cultured agar plates w/ CSF. At this lab, aspiration from
blood culture bottles was performed at an open lab bench.
#2: Microbiologist who worked at state public health lab and
worked on several n meningitides isolates performed slide
agglutination tests. Used BioSafety Level 2 precautions.
In 15 years, there were 16 cases of meningitis in lab personnel, of
which 50% were fatal.
From MMWR 2/22/02
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Other Possible Pathogen Exposures
Fungal agents:
Coccidioimycosis and Histoplasmosis
Hazard because spores are
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Other Possible Pathogen Exposure
Parasitic agents:
Intestinal (giardia, toxoplasmosis), tissue and
organs (trichinosis), blood (malaria)
Ingestion is primary hazard
Also can enter body through breaks in the skin
CDC webpage on parasitic diseases
CDC webpage in giardia
http://www.cdc.gov/ncidod/dpd/http://www.cdc.gov/ncidod/dpd/parasites/giardiasis/moreinfo_giardiasis.htmhttp://www.cdc.gov/ncidod/dpd/parasites/giardiasis/moreinfo_giardiasis.htmhttp://www.cdc.gov/ncidod/dpd/ -
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Other Possible Pathogen Exposure
Prions:
Transmissible spongiform encephalopathies Present in CNS of animals
Resistant to conventional inactivation
No known treatment
Includes Creutzfeldt-Jakob disease
Link to CDC Prion Diseases webpage
This tissue slide shows sponge-like lesions in the
brain tissue of a classic CJD patient. This lesion
is typical of many prion diseases.
http://www.cdc.gov/ncidod/dvrd/prions/index.htmhttp://www.cdc.gov/ncidod/dvrd/prions/index.htm -
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Other Possible Pathogen Exposures
Rickettsial Agents: Coxiella burnetti Q fever
o High risk of lab infection
oAerosol and parenteral exposures
Rickettsia species
o Typhus, reported in 57 lab-associated cases
o Rocky mountain spotted fever, in 1976, 63 lab
cases were reported, 11 were fataloAerosols and parenteral inoculation
CDC webpage on Q Fever CDC webpage on Rickettsia
http://www.cdc.gov/ncidod/dvrd/qfever/index.htmhttp://www.cdc.gov/ticks/diseases/other_spotted_fevers/http://www.cdc.gov/ticks/diseases/other_spotted_fevers/http://www.cdc.gov/ncidod/dvrd/qfever/index.htm -
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Virus Exposure
Some viruses are transmitted via aerosols
such as: Hantavirus lab infections have occurred
during rodent handling
Human herpes viruses Influenza
Various pox viruses
Herpes viruses are ubiquitous primarily an opportunistic infection. Rarely,
cytomegalovirus or Epstein-Barr may be transmitted in the lab. No documentation
that influenza has been contracted in the lab as it also is ubiquitous in season.
CDC lab management of agents associated with hantavirus
interim biosafety guidelines -1994
http://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdfhttp://www.cdc.gov/mmwr/PDF/rr/rr4307.pdf -
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Virus Exposure Blood/Body Fluids
Some pathogens are transmitted through
microorganisms contained in blood and other
body fluids.
Examples are:
Hepatitis B Virus (HBV)
Hepatitis C Virus (HCV)
Hepatitis D Virus (HDV)
Human Immunodeficiency Virus (HIV)
Link to Exposure to Blood brochure
http://www.cdc.gov/ncidod/dhqp/pdf/bbp/Exp_to_Blood.pdfhttp://www.cdc.gov/ncidod/dhqp/pdf/bbp/Exp_to_Blood.pdf -
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Virus Exposure Blood/Body Fluids
Blood includes:
Human blood
Human blood components, such as
packed cells and plasma
Products made from human blood, such
as:
Clotting agents for hemophilia
Immune globulins including Rh factor immune
globulins
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Potentially infectious body fluids include:
Virus Exposure Blood/Body Fluids
Semen
Vaginal secretions
Cerebrospinal fluid
Synovial fluid
Pleural fluid
Pericardial fluid
Peritoneal fluid
Amniotic fluid
Saliva in dental
procedures
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Virus Exposure Blood/Body Fluids
Other pathogens that can also be transmitted
through blood include:
Malaria
Syphilis
Brucellosis
Leptospirosis
Cruetzfeldt-Jakob Disease
Some fungi and ricketsii
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Virus Exposure
Hepatitis A and E:
Fecally transmitted
We hear about it in the news when infected
restaurant workers may expose a community
Although high virus titers may be present in blood
during the incubation period, lab transmission notreported
Hepatitis A virus
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Virus Exposure Blood/Body Fluids
Hepatitis B, C, and D
Transmitted via blood or other body
fluids
Causes liver inflammation and/or
damage - mild to fatal
Can live in a dry environment > 7 days,
such as on countertop
Highest risk of transmission through
hollow bore needle stick
Healthy human liver
Hepatitis C liver
Copyright1998
TrusteesofDartmouthC
ollege
http://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.htmlhttp://www.epidemic.org/rightsReserved.html -
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Virus Exposure Blood/Body Fluids
Hepatitis B, C, and D
Hepatitis B, active and passive vaccines available
Hepatitis C, no vaccine available
Hepatitis D, no vaccine available, however
immunization against hepatitis B also protects
against hepatitis D
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Virus Exposure Blood/Body Fluids
Human Immunodeficiency Virus (HIV) Attacks the human immune system
Can live in a dry environment for only
a few hours
No vaccine available
Antiviral post-exposure prophylaxis
effective in reducing risk
Reference: MMWR June 29, 2001/50(RR11);1-42
HIV - seen as smallspheres on the surfaceof white blood cells
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HIV Virus Exposure Routes
Parenteral Needlestick
Scalpel/glass cut
Mucous membrane
Mouth pipetting
Eating, drinking in lab area
Not wearing appropriate PPE
Non-intact skino Unguarded splash
o Contact with contaminated surfaces
o Not covering skin breaks
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HIV Virus Exposure
Occupationally acquired HIV :The CDC reports as of December 2001, 51 of the 57 cases
of occupationally acquired HIV infection involved sharps
injuries of which nearly half involved needles used in
phlebotomy or blood sampling from a vascular line, withvacuum- tube device needles accounting for the largest
number of these injuries.
Other sharps injuries included broken glass from blood
collection tubes and a needle for cleaning/dislodging debrisin laboratory equipment.
Reference: Surveillance of Occupationally Acquired
HIV/AIDS in Healthcare Personnel December, 2006
http://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.htmlhttp://www.cdc.gov/ncidod/dhqp/bp_hcp_w_hiv.html -
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Lab Practices & Biosafety Guidelines
The Centers for Disease Control (CDC) hasguidelines to describe combinations of:
Laboratory Practices and Techniques
o Standard Practiceso Special Practices
Safety Equipment
Laboratory Facilities
CDC Laboratory Guidelines and Standards webpage
CDC Biosafety Webpage includes a biosecurity online training course
http://wwwn.cdc.gov/dls/guidstd.aspxhttp://www.cdc.gov/biosafety/http://www.cdc.gov/biosafety/http://wwwn.cdc.gov/dls/guidstd.aspx -
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CDC Biosafety Guidelines
These guidelines are called:
Biosafety in Medical and Biomedical Laboratories(BMBL - 5th edition)*
The guidelines describe four laboratory hazard
levels or Biosafety Levels (BSL)
* Someof the information in this module is derived from this document
http://www.cdc.gov/biosafety/publications/bmbl5/index.htmhttp://www.cdc.gov/biosafety/publications/bmbl5/index.htmhttp://www.cdc.gov/biosafety/publications/bmbl5/index.htm -
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Biosafety Guidelines
Biosafety Levels 1- 4 provide:
Increasing levels of personnel and
environmental protection
Guidelines for working safely in
microbiological and biomedicallaboratories
Class I Biosafety Cabinet(from CDC publicationSelection,
Installation & Use of Biosafety Cabinets)
http://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdfhttp://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdfhttp://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdfhttp://www.cdc.gov/biosafety/publications/bmbl5/BMBL5_appendixA.pdf -
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Biosafety Levels (BSL)
The Four Biosafety Levels are:
BSL1 - agents not known to cause disease (B. subtilis, E. coli).
BSL2 - agents associated with human disease (hepatitis B,
Salmonellae, Toxoplasma)
BSL3 - indigenous/exotic agents associated with human disease
and with potential for aerosol transmission (M. tuberculosis, C.
burnetii).
BSL4 - dangerous/exotic agents of life threatening nature(Marbug and Ebola virus).
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DOSH Rules related to biological hazards
Occupational Exposure to BloodbornePathogensWAC 296-823
This rule provides requirements to protect
employees from exposure to blood or otherpotentially infectious materials, that may
contain bloodborne pathogens.
The rule covers anticipated exposure, even
if no actual incidents have occurred.
Link to Online Training course on Bloodborne Pathogens
http://www.lni.wa.gov/wisha/rules/bbpathogens/default.htmhttp://www.lni.wa.gov/Safety/TrainTools/Online/Courses/default.asp?P_ID=200http://www.lni.wa.gov/Safety/TrainTools/Online/Courses/default.asp?P_ID=200http://www.lni.wa.gov/wisha/rules/bbpathogens/default.htmhttp://www.lni.wa.gov/wisha/rules/bbpathogens/default.htmhttp://www.lni.wa.gov/wisha/rules/bbpathogens/default.htm -
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Other Related DOSH Rules & Directives
Protect Employees from BiologicalAgents 296-800-11045 refers toCDC guidelines
Personal Protective Equipment,
296-800-160
Tuberculosis - WRD 11.35
http://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/Safety/Rules/Policies/PDFs/WRD1135.pdfhttp://www.lni.wa.gov/Safety/Rules/Policies/PDFs/WRD1135.pdfhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-160.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htmhttp://www.lni.wa.gov/wisha/rules/corerules/HTML/296-800-110.htm