Presentation on theme: "Occupational Illness Amongst Laboratory Workers From an Initially Unrecognized Laboratory Exposure to Coccidioides immitis/posadasii William Ciccotelli."— Presentation transcript:
Occupational Illness Amongst Laboratory Workers From an Initially Unrecognized Laboratory Exposure to Coccidioides immitis/posadasii William Ciccotelli 1,3,4, Ruth Schertzberg 1, Anne Rocchi 2, Frank Vona 2, Jessica Kooger 1, Karen Parkinson 2, John Vanderlaan 3, John H. Murphy 5,7, Jeff Fuller 8, Susan E. Richardson 6,7 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, Hamilton 4, ON, Canada, Resource Environmental Associates Limited, 5 Markham, ON, Canada, Public Health Ontario Laboratories 6, Toronto, ON, Canada and University of Toronto 7, Toronto, ON, Canada, Department of Laboratory Medicine and Pathology, University of Alberta 8, Edmonton, AB, Canada BackgroundMaterials & MethodsResults Conclusion 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. 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 E 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 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). 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. No Disclosures Figure 1: Analysis for the potential spatial dispersion of C. immitis/podasii arthroconidia in F305.