Transcript Occupational Health & Safety for Animal Biocontainment Work

Agent Specific Occupational
Health & Safety Training
Thomas H. Winters, MD, FACOEM
Medical Director
Occupational & Environmental Health Network
Waltham, MA
Objectives
• Describe categories and types of agents
and their exposure risks
• List available vaccines
• Identify appropriate steps for exposure
including reporting, treatment and
follow-up
Risk Assessment
• BLS 1, 2, 3 or 4
• Types of exposures
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Bacterial
Viral
Toxins
Chemical
Rickettsial, protozoal, helminth, fungus
• Risk of disease usually same as exposure risk
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Inhalation, mucosal contact, or nonintact skin contact
Amount of dose
Vaccination and antibody titers
Virulence of the organism
Associated illness or medications
Prophylactic antibiotics
Reference: Rusnack et al, 2004, p. 791
Gap Analysis
• Review of policies
• Review of procedures
• Assessment of current training program
• Evaluation of current protective
measures
• Assessment of expert resources
Levels of Protection
• OSHA
• Engineering controls
• Work practice controls
• Administrative controls
• PPE
Pre-Placement Evaluations
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Obtain accurate job description
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History
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Physical
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Speak with direct supervisor if require clarification
General health history
Obtain immunization records
Previous occupational exposures
Focus
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Cardiac
Respiratory
Immunologic
Skin
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Baseline lab work-exposure dependent
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Other exposure dependent testing
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CBC, LFT, Chem-20
Titers
Serum storageLaboratory personnel
Immunizations/monitoring (i.e. Hepatitis B vaccine, baseline serum samples, TB skin testing)
Immuno-compromised person evaluation/policy
Chest x-ray
EKG
PFTs
Pre-Placement Evaluations
• Baseline lab work-exposure dependent
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CBC, LFT, Chem-20
Titers
Serum storage laboratory personnel
Immunizations/monitoring (i.e. Hepatitis B vaccine,
baseline serum samples, TB skin testing)
• Immuno-compromised person evaluation/policy
• Other exposure dependent testing
• Chest x-ray
• EKG
• PFTs
Annual Medical Surveillance
• Questionnaire
• Answers may trigger physical and
additional testing
• History
• Change in job status or exposure type
• Physical
• Laboratory testing
• Exposure specific
Common Agents
 AGENTS CAUSE HUMAN DISEASE WITH SERIOUS OR
LETHAL CONSEQUENCES; INDIGENOUS OR EXOTIC
• Human cell lines
• Shigella
• Borrelia burgdorferi
• Erlichia (HGE)
• Babesia microti (human babesiosis)
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Plasmodium spp (rodent)
Plasmodium spp (mosquito born)
Mycobacterium Tuberculosis
Vaccinia
Adenovirus
Herpes Simplex virus
E Coli
Francisella tularensis
Hepatitis B, C
Poliovirus
HIV
Vaccinations
• Exposure specific
• Many vaccines are investigational
Vaccines
• FDA approved
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Anthrax
Yellow fever
Smallpox
Plaque
Ref: Rusnack et al, 2004, p. 793
• Not FDA approved
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Tulermia
Q Fever
EEE
Pentavalent
Botulism toxoid
Allergies
• Latex
• Lab animals
• Irritant contact dermatitis
• Frequently related to PPE
Occupational Asthma
• Animal handlers
• Allergies
• Pre-existing
• RAST
• RAST for other allergens: rabbit, non-human
primates, gerbils
• Prick test
• Mouse urine antigen, mouse epithelium, bedding
• Occupationally acquired
Post-Exposure Prophylaxis
• Bacterial agents
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Salmonella, Shigella
Anthrax
Plaque
Tularemia
• Viral agents
• HIV, Hep B, Hep C
• Influenza
• Vaccinia
• Toxins
• Few of options
• ClL. Botulinum-trivalent equine anti-toxin
Employee Training
• Education
• Critical to minimize exposure risk
• Increase understanding to improve rapid
reporting to optimize outcomes
• Employee awareness regarding resources
• 24/7 expert medical coverage
• MD, NP
Respiratory Protection Program
• Fit testing
• Education
• Periodic spirometry
• Annual questionnaire
• May trigger physical examination
• Compliance
PPE
• Eye wear, face shields
• Protective clothing
• Gloves
• Nitrile
• Chemical
Final Evaluations
• Written report
• Pre-placement
• Fit for duty
• Fit for duty with restrictions
• Not fit for duty
• Medical hold
Assessment of Factors Influencing the
Disease Risk After Exposure to an Agent
• The risk of disease is usually the same as exposure risk or lower if
individuals had prior vaccination, exposure to nonpathogenic strain, or
given antibiotic prophylaxis.
• Was there inhalation, mucosal contact, or non-intact skin contact with
agent? Was there immediate cleansing with disinfectant (time interval
from incident to cleansing)? Immediate cleansing of agent may reduce
disease risk.
• What was the estimated dose of exposure? What is the estimated
infective dose/lethal dose of the agent?
• Was the individual vaccinated against the agent? Do they have
protective antibody titers? How effective is the vaccine? Prior
vaccination may lower the risk of disease.
• What is the virulence of the organism? Exposure to non-virulent strains
may lower disease risk (i.e. non-virulent Steme strain of B. anthracis).
• Does individual have an illness or take medications that predispose for
higher risk for disease?
• Are prophylactic antibiotics available against the organism? Postexposure antibiotic prophylaxis may lower disease risk. Consider
investigational antiviral agents in individuals with moderate to highrisk viral exposures who are not vaccinated to lower the risk of disease.
Ref: Rusnak et al., 2006; Heymann, 2004, Winters, 2006
Post-Exposure Evaluation
• Employee interview
• Categorize exposure
• Medical history
• Physical exam
Case Study
• 25 yr old female graduate student at a major
university presents to University Health
Services with a two day history of fever to
103, abdominal pain, bloody/watery
diarrhea, shaking chills, nausea, vomiting,
anorexia and abdominal pain. She has taken
loperamide for the diarrhea and tenesmus
which she believes has made her symptoms
worse.
Clinical Investigation
• Past medical history
• Recent travel
• Occupation
• Student
• Research activities/exposures
Differential Diagnosis
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Influenza
E coli
Shigellosis
Salmonella
Campylobacter jejuni
Schistosoma
Entamoeba histolytica
Ulcerative colitis
Diagnosis
• Shigellosis
• Four types of Shigella:
• S. dysenteriae, S. flexneri, S. boydii, and S. sonnei.
• Shigella dysenteriae 1 (Shiga toxin)
• Rare in the U.S. – this finding likely lab related with no travel history
• Incubation: 1-4 days
Duration: 5-7 days
• Complications may include:
• Toxic megacolon
• Intestinal perforation
• Hemolytic uremic syndrome (HUS)
• Case fatality rate as high as 20% among hospitalized cases (Heymann,
2004,p. 487)
• 8% of patients with HUS develop lifelong complications such as HTN,
seizures, blindness or paralysis
Ref: http://www.niaid.nih.gov/factsheets/shigellosis.htm
Diagnostic Testing
• Microscopy of fresh stool (time
sensitive- within 2 hours)
• Stool culture and serotyping
• Enzyme immunoassay for Stx for S
dysenteriae type 1
Ref: http://www.emedicine.com/ped/topic2085.htm
Treatment
• Most cases resolve within 5-7 days
• Hospitalized
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Supportive therapy
Intravenous fluids
Antipyretics
Anti-diarrheals not typically used- may make
prolong/worsen course illness
• Increasing resistance to TMP-SMZ and ampicillin
• Ciprofloxacin 500mg po x 5 days, or Z-pack
• Monitor for complications (HUS)
Prevention
• Lab safety re-education
• Hand washing
• Policy/procedure review
• Rapid reporting of breech in lab proctols
References
• Cohen, J. and Powderly, W. ( 2004) Infectious diseases, 2nd ed. St.
Louis: Mosby.
• Heymann, D. L. ed. (2004). Control of communicable diseases
manual, 18th ed. Washington, DC: American Public Health
Association.
• National Research Council. (1997). Occupational health and safety
in the care and use of research animals. Washington, DC: National
Academy Press
• Rusnak, J. M. et al. (2004, August). Management guidelines for
laboratory exposures to agents of bioterrorism. JOEM, 46 (8),
791-800.
• U.S. Department of Health and Human Services. (1999).
Biosafety in microbiological and biomedical laboratories, 4th ed.
Washington, DC: U.S. Government Printing Office.
• http://www.cdc.gov/od/ohs/pdffiles/4th%20BMBL.pdf