Download Sample research poster - Resource Environmental Associates

Occupational Illness Amongst Laboratory Workers From an Initially
Unrecognized Laboratory Exposure to Coccidioides immitis/posadasii
1,3,4
Ciccotelli ,
1
Schertzberg ,
2
Rocchi ,
2
Vona ,
William
Ruth
Anne
Frank
Jessica
1
2
3
5,7
8
Kooger , Karen Parkinson , John Vanderlaan , John H. Murphy , Jeff Fuller ,
6,7
Susan E. Richardson
Department of Infection Prevention and Control,1 Department of Occupational Health Safety and Wellness,2 Department of Laboratory Medicine,3 Grand River Hospital, Kitchener, ON,
Canada, Department of Pathology & Molecular Medicine McMaster University, Hamilton4, ON, Canada, Resource Environmental Associates Limited,5 Markham, ON, Canada, Public Health Ontario Laboratories6,
Toronto, ON, Canada and University of Toronto7, Toronto, ON, Canada, Department of Laboratory Medicine and Pathology, University of Alberta8, Edmonton, AB, Canada
Background
Coccidioides immitis/posadasii is
a known risk to laboratory staff
given the low infectious dose and
potential for highly concentrated
growth of the sporulating
infectious mycelial form. Little is
known about the impact of
occupational exposure on a
laboratory wide scale. On April 2,
2012 an accidental release of C.
immitis/posadasii occurred. Two
petri dishes (2 weeks of room
temperature growth) were
discarded into an open container
causing the parafilm seal to
break. This exposed confluent
mold growth in a biological safety
level 2 microbiology lab with a
four hour delay in recognizing the
event. The laboratory department
was evacuated based on
concerns of the microbiology lab
was under positive pressure and
potential department wide air
recirculation.
Materials & Methods
All data were collected prospectively. Study was approved by our
Research Ethics Board and worker consent was required to release
data.
Spore Dispersion Modeling
• Gaussian dispersion model was used to evaluate the extent of
potential exposure to arthroconidia within proximity to
microbiology.
• Surface sampling for settled arthroconidia was performed
throughout the lab in accordance with ASTM E1216-11 Standard
Practice for Particulate Contamination by Tape Lift.
Decontamination of Laboratory Space
• Decontamination with 4.5 % accelerated hydrogen peroxide
was performed by a professional remediation company. Items
not exposed to potential arthroconidia settling were retained.
• A chemical quality indicator was utilized to ensure thorough
application.
Occupational Assessment for C. immitis/posadasii Exposure and
Infection
• Education for compatible symptoms was provided to all exposed
staff. Symptomatic staff reported to the Occupational Health
department, and standard diagnostic tests were used to
determine possible etiology.
• Potentially exposed staff completed a questionnaire (travel history
within the lab department), and underwent baseline and 6 week
post exposure serology.
• Staff considered high risk (work location and/or co-morbidities for
disseminated infection) were offered fluconazole (400mg daily)
prophylaxis, which was discontinued if no clinical symptoms
emerged and 3 week post exposure serology was nonreactive.
• Serological analysis for IgM and IgG were performed using EIA,
complement fixation and immunodiffusion assays
Results
Spore Dispersion Modeling
• Microbiology lab was under positive pressure (Figure
1) and there was no department wide recirculation of
air (not shown).
• The model revealed potential for arthroconidia
dispersal into the hallway and laboratory areas
adjacent and down wind to the site of release (Figure
1)
• Tape lift sampling of surfaces did not detect any
spores morphologically (by microscopy) consistent
with Coccidiodes sp., including within the
microbiology lab and other “at risk” laboratory areas.
Decontamination of Laboratory Space
• Laboratory spaces and common areas (Figure 1)
were decontaminated.
• All quality indicator surfaces passed.
Occupational Assessment for C. immitis/posadasii
Exposure and Infection
• Ninety staff members were potentially exposed and
underwent physical decontamination.
• Eighty-one percent (73/90) of staff consented to
release health information, including all microbiology
staff (14/14) and sixty-one percent of adjacent
laboratory staff (11/18).
• All microbiology staff completed the fluconazole
prophylaxis to 3 weeks.
• Two staff tested positive at baseline for IgM by EIA
only, and had no confirmed travel to endemic areas.
These were considered false positive results.
• No staff had clinical symptoms or seroconverted at 3
or 6 weeks post exposure (any methodology).
Conclusion
• Spore dispersion model did not
under estimate potential exposure
based on the lack of clinical cases
and seroconversions.
• Despite a potential high risk
laboratory exposure, there were
no clinical cases compatible with
coccidioidomycosis or evidence of
infection on serologic testing.
• This unexpected event has lead
to further improvements in
laboratory biosafety, especially as
it related to specimen storage and
infrequently encountered
organisms.
Figure 1: Analysis for the potential
spatial dispersion of C.
immitis/podasii arthroconidia in
F305.
No Disclosures