Bloodborne Pathogen Training for Laboratory Workers

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Bloodborne Pathogen Trainingfor Laboratory
Workers
Louisiana State University

• Safety precautions to prevent laboratory-acquired
  infections among research laboratory personnel.

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Application

• Handling human specimens or bloodborne pathogens
  must conform to federal regulations (OSHA
  Bloodborne Pathogen Standard, 29 CFR 1910.1030).
• The regulations cover all research with
• live human bloodborne pathogens (HIV, HBV, HCV,
  etc.)
• unfixed human tissues, blood, and body fluids

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Bloodborne Pathogens

• A bloodborne pathogen is any human pathogen that
  is transmitted to humans by perenteral contact
  with infected blood.
• Includes, but not limited to the following
• retroviruses HIV-1, HIV-2, HTLV-I, -II
• hepatitis viruses HBV, HCV
• arboviruses causing encephalitis, YF virus,
  Dengue virus, others
• other microbial pathogens Plasmodium spp.,
  Franciscella tularensis, Treponema pallidum,
  others

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HBV
HIV
YFV
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HIV Infection

• HIV viruses establish a chronic infection of
  human CD4 cells helper T-lymphocytes and
  macrophage.
• Currently there is no vaccine available and drug
  therapies are effective at limiting progression
  of disease but not curing infection.

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Transmission

• HIV is mainly transmitted by sexual contact with
  an infected person.
• sexual transmission can occur at genital or
  colonic mucosa
• virus is present in semen or vaginal fluids
• virus gains access to the bloodstream by passing
  through openings in the mucous membranes - the
  protective tissue layer that lines the mouth,
  vagina and rectum- and through breaks in the skin
  of the penis.

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Transmission

• Exposure to infected blood or blood products
• transfusions, mainly in the developing world
  today
• intravenous drug use, sharing of needles
• main transmission in eastern Europe and former
  Soviet Union states
• accidental needle-sticks or exposure of blood to
  open cuts or scrapes

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Transmission

• The third major route of infection is from mother
  to child
• mainly occurs during birth, when there is mixing
  of the blood
• can also occur before birth the virus can cross
  the placenta and invade the developing fetus
• virus is present in milk, but there is no
  evidence for transmission by breast-feeding

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Epidemiology of HIV in U.S.
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Early Signs / Symptoms of HIV infection

• Initial signs are mononucleosis-like
• swollen, tender lymph nodes
• fever
• sore throat, headache
• muscle aches
• rash, diarrhea may be present
• A vigorous immune response occurs
• virus levels in blood decline
• Sharp decline in circulating CD4 T-cells, then
  numbers recover

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HBV Infection

• HBV is a small DNA virus in the family
  Hepadnaviridae that causes both self-limiting and
  chronic infections of humans
• self limiting - resolve within 6 months
• most are sub-clinical
• some result in acute hepatitis
• persistent - a fraction of infections become
  persistent and may continue for many years or
  life.
• can lead to liver damage or hepatocellular
  carcinoma

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HBV Infection

• Clearance of HBV in infected persons is
  associated with development of immune responses
  to the product of the S gene, the major surface
  protein, HbsAg.

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Self-limiting Typical course of acute infections
with HBV
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Self-limiting Sub-clinical infection in HBsAg
negative individuals
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Typical course of persistent infections with HBV
HbsAg persists
No antibody to HbsAg
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Vaccine

• The vaccine for HBV is purified recombinant
  HbsAg.
• Series of three injections 0, 1 and 6 months.
• Duration of immunity is at least 15 years.
• Efficacy is 95 safety is excellent
• side effects are nearly always mild and occur at
  low incidence

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Transmission of HBV

• Humans are the only reservoir, and chronic
  carriers are the main source of new infections.
• HBV is present in and can be transmitted from
  contact with
• blood and serum
• saliva
• semen

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Transmission of HBV

• Virus is also present in
• feces
• cerebrospinal fluid
• bile
• breast milk
• sweat
• vaginal secretions
• mosquitoes and bedbugs
• Transmission is rare or not possible from the
  above fluids.

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Transmission of HBV

• Established routes of infection
• percutaneous transfer of blood
• mucous membrane contact with blood
• homosexual and heterosexual intercourse
• contact between mucous membranes or cuts and
  environmental surfaces contaminated with virus
• neonatal transmission is mainly at birth
• 5-10 of neonatal infections may be in utero

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HBV Epidemiology
Currently there are about 8800 new cases of HBV
reported each year estimated 80,000 total. Of
these, about 10 will become chronic
carriers. About 1.25 million people in U.S. have
chronic HBV infection.
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Exposure Control Plan

• Universal precautions
• Engineering controls
• Work practice controls
• Medical management

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Universal Precautions

• The universal precautions were developed in the
  early 1980s to protect health care workers from
  HIV infection.
• The philosophy of universal precautions is that
  all patients, samples, and specimens should be
  treated as if infected at all times.
• barrier and procedural protections are used when
  handling all samples or specimens.

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Strategies for Protection

• Strategies for protection against bloodborne
  pathogens include the following
• appropriate protective clothing and barriers
• minimizing the use of sharps
• practices that minimize the risk of infection are
  used in all manipulations
• appropriate safety equipment and supplies are
  used when handling infectious materials
• vaccination

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Personal Protective Equipment
Personal protective equipment (PPE) should be
used for all manipulations of blood, tissue,
infected cultures, or other potentially
infectious materials (OPIM).
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Personal Protective Equipment

• Gloves
• protection from direct skin contact
• some protective effect from needle
  -sticks
• required for any hand contact with
  blood, cultures, infected animals,
  potentially contaminated equipment
• use for all procedures, cleaning spills and
  handling wastes
• should use two layers when working with cultures
  or using sharps with infectious materials
• removed inside out for discard

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Personal Protective Equipment

• Protective outer clothing
• lab coats, gowns, or aprons are required
  at all times in a BBP lab
• solid-front, fluid-resistant gowns should be
  used for any procedure where splashes are
  possible
• as necessary, add hoods, caps, face protection
  and disposable shoe coverings
• all protective clothing must be removed before
  leaving the lab and either disposable, laundered
  on-site, or autoclaved before removal from site

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Personal Protective Equipment

• Eye protection
• eye protection should be worn at all times in the
  lab
• appropriate eye protection include safety glasses
  with side-splash protection, safety goggles or
  full face shield
• prescription eyeglasses are not a substitute
  safety glasses should be worn over eyeglasses

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Safety Engineered Materials

• Glassware should be avoided if possible and
  replaced with plastic tubes, flasks, etc.
• Capillary tubes, if used for micro-hematocrit
  measurements, should be made of unbreakable
  plastic or glass coated with plastic.

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Safety Engineered Materials

• If needles are used, safety needles should be
  substituted for standard if possible
• If other sharps are necessary, safety-engineered
  substitutes should be employed

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Biological Safety Cabinets

• A properly maintained and certified BSC must be
  used for all open work with infectious materials
  in a BBP research laboratory.

some procedures may not be feasible inside a
cabinet in such cases, extra PPE may substitute.
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Use of a BSC should not substitute for protective
clothing or eye protection.
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Work Practices

• BSL-2 practices apply
• no eating, drinking, smoking, storage of food or
  drinks, application of cosmetics or handling of
  contact lenses in lab
• procedures involving potentially infectious
  materials done in ways that minimize splashing or
  the production of droplets
• PPE is removed and replaced when contaminated,
  and removed before exiting the lab

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Mouth pipetting is not permitted.
Work surfaces should be kept free of potential
hazards.
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Vacuum tubes of blood and other potentially
infectious materials should be covered with
absorbent matting during opening.
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Handwashing is an effective way to prevent mucous
membrane exposures. It should be done 1)
whenever hands become visibly contaminated with
material 2) after completion of work with
infectious materials 3) after removal of
gloves 4) before leaving the laboratory
After leaving the lab, hands should again be
washed before 1) eating, drinking or smoking 2)
handling contact lenses
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Absorbent lab matting reduces the risk of
splashes if infectious materials are spilled on
work surfaces. Lab matting also helps
contain spills.
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Cleaning and disinfection of work surfaces
should be done after completion of each
procedure and at the end of each work day.
A variety of chemical agents are effective
against most bloodborne pathogens iodophors,
phenolics, alcohol, diluted bleach (10 v/v). The
presence of blood or other organic material can
limit the effectiveness of most chemical agents.
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Infectious Spill Management
1) Alert co-workers and use PPE. 2) Flood the
spill with an appropriate disinfectant bleach to
final 10 is a good choice. 3) If glass is
present, use tongs to pick up and discard in
sharps container. 4) Absorb the
spill/disinfectant mix with paper towels, lab
matting, or granular material. 5) Carefully
scrape up the absorbent materials and discard in
biohazard waste. 6) Clean and disinfect the area.
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Sharps Management
The use of sharps in bloodborne pathogen labs is
responsible for gt90 of researcher exposures
mainly needle-sticks.
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Sharps Management
1) Wear two pairs of gloves when working with
sharps and infectious materials. 2) Discard used
sharps immediately without recapping into
hard-sided, leak-proof disposal containers.
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Waste Management
1) Solid wastes should be collected into two
layers of autoclavable biohazard bags, placed
within leak-proof, labeled secondary
containers. 2) Collection bags should be removed
from secondary containers before overflowing and
only at the time of decontamination. 3) All
laboratory wastes should be autoclaved before
disposal into the waste stream (BSL-3).
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Waste Management
Liquid wastes with low numbers of pathogens may
be decontaminated by exposure to chemical
disinfectant, and discarded by sanitary
sewer. Culture fluids and other materials
expected to have large numbers of pathogens
should be autoclaved before discard.
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Restricted Access
1) Lab doors are closed when work is in
progress. 2) PI establishes specific entry
requirements and policies. 3) All persons enter
the lab must be made aware of the hazards present
in the lab. 4) A biohazard warning sign is posted
at the entrance to the lab, other signs as
appropriate.
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Medical Management

• Hepatitis B vaccine
• Post-exposure evaluation
• Occupational surveillance

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Hepatitis B Vaccine

• All BBP lab workers are offered the hepatitis B
  vaccine free of charge.
• LSU Student Health Center administers the vaccine
  and maintains the records.
• People who have previously been vaccinated, have
  antibody to HbsAg, or are contraindicated for
  medical reasons do not need the vaccine.
• Those who refuse the vaccine must sign a
  declination form.
• may reconsider vaccine at any time

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Post-Exposure Evaluation

• Exposure - eye, mouth, other mucous membrane,
  non-intact skin, or parenteral contact with blood
  or other potentially infectious materials
  resulting from the performance of employees
  duties.
• All work-related exposures require immediate
  action and follow-up evaluation.

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Immediate Action

• Needle-sticks or other non-intact skin exposures
• Immediately wash with soap and hot water, then
  seek medical treatment.
• Splashes to nose, mouth, or eyes
• flush extensively with water, saline or sterile
  irrigating solution, then seek medical treatment.
• Notify lab director / principle investigator.
• documentation and reports are required by LSU

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Follow-up Evaluation

• LSU Student Health Center will offer the exposed
  individual
• confidential medical evaluation
• blood collection and HIV testing
• post-exposure prophylaxis with anti-retroviral
  drugs
• as directed by current CDC recommendations
• counseling
• evaluation of subsequent reported illnesses
  resulting from the exposure

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Thank you for your attention!

• For additional questions or concerns
• Contact
• Occupational and Environmental Safety
• 126 Public Safety Building
• 578-5640