C. Torres, Intel Corporation, Colorado Springs, CO; J. Hartle, Intel Corporation, Santa Clara, CA.
This presentation will outline the approaches taken to develop, implement, and sustain a biosafety program from concept to completion. Due to R&D usage of increasingly complex biological agents in company-owned laboratories, a nascent biosafety program was required. The newly developed program, in addition to special focus by existing industrial hygiene resources, was needed to ensure that potential hazards were controlled per recognized best practices. This represented a particular challenge due to the fact that biological research had not occurred previously within the company and that existing internal professional biosafety experience was limited at best. In the course of the presentation the following topics will be addressed. The situation: the means of discovery of new research initiatives, initial responses to EHS/biosafety and R&D roadmap concerns; interim solutions to ensure current researchers were adequately protected and regulatory requirements were being met; and long-term plans to develop, implement and sustain a new comprehensive biosafety program. The problems: obtaining requisite biosafety expertise to achieve interim solutions while growing expertise internally to support on-going program maintenance; how to communicate interim and long-term solutions to researchers, management and other interested stakeholders; and how to obtain necessary management approval for cost implications of interim and long-term solutions. The resolutions: explanation of our interim solution to use an external biosafety consultant to ensure current and planned research activities were consistent with OSHA bloodborne pathogen requirements and CDC/NIH best practices; describe strategy to stay engaged with internal business groups to understand research roadmap, ensure compliance with biosafety program requirements; develop a biosafety culture and enable success; and development/ implementation of comprehensive Biosafety program as the long-term solution. Finally, the presentation will address benefits to others such as forming a strategy to develop interim and long-term solutions while utilizing external and internal resources to effectively respond to emerging EHS needs.
A. Hogan, Becton, Dickinson and Company, Washington, DC; N. Hauter, U.S. DOL/OSHA, Chicago, IL.
Health care workers face new challenges and risks associated with occupational exposure to microbes, multidrug resistant organisms, emerging resistance, and newly re-emerging pathogens of old. The major contributing factors to such exposures include: longer living chronically ill patients, over- or misprescribing of antibiotics, overcrowded and understaffed healthcare facilities, ease and increase of global travel, poor hygiene and work practices, over-”juiced” agricultural products, and underfunded and undersupported infection prevention and control programs. This presentation will explore these exposures, controls for exposures, illustrate case studies, present incidence/prevalence data, and present financial and societal burden. This will prove to be an enlightening, yet eerie perspective, on how the new frontier of health care worker safety and health directly impacts patient safety, community wellness, and public health.
G. Croteau, J. Camp, M. Yost, University of Washington, Seattle, WA; D. Martin, A. Heald, Targeted Genetics Corporation, Seattle, WA.
A study was conducted to assess health care worker exposure to tgAAVCF during the aerosolized administration of this experimental gene transfer agent in clinical trials for the treatment of cystic fibrosis. tgAAVCF is a recombinant adeno-associated virus (AAV) genetically engineered to contain the human cystic fibrosis transmembrane conductance regulator cDNA. Study subjects included eight health care workers involved in the administration of tgAAVCF in a Phase II study and 12 control health care workers who were involved with the treatment of CF patients but not administration of the study drug. The exposure assessment entailed the determination of personal and area airborne tgAAVCF concentrations. In addition, serologic status of the health care workers was evaluated throughout the study for the presence of antibodies to AAV. A symptom survey was also completed by both the active and control health care workers. Air samples were analyzed by an infectivity assay (active vector) and a DNA polymerase chain reaction amplification procedure (vector DNA). Air monitoring was conducted during 13 tgAAVCF and 7 placebo administrations. Active vector and vector particles were detected in 4 of 51 and 48 of 51 air samples collected during the administration of tgAAVCF, respectively. Based on the airborne vector particle concentration, the workers’ exposure was estimated to be 0.0006% of the administered dose. At this level of exposure, the prevalence of symptoms was very low, the spectrum was similar in both study groups and did not result in any reported negative health effects.
C. Keil, Bowling Green State University, Bowling Green, OH; D. Clutts, Toledo Hospital, Toledo, OH.
Hospitals require special ventilation in rooms that house patients with certain airborne infectious diseases, such as tuberculosis. The Centers for Disease Control (CDC) and American Institute for Architects specify a ventilation rate of 12 air changes per hour exhausted directly outside or recirculated through a HEPA filter, with a negative differential pressure between the room and the hallway. However, meeting this mechanical ventilation rate does not necessarily mean that all room air is exchanged at that rate. The room configuration, furniture, and the location of the supply/exhaust grills, and the movements of the patient, staff, visitors create air currents that both distribute infectious aerosols and affect effective ventilation rates throughout the room. The CDC suggests a qualitative method using smoke sticks to determine areas in rooms where there is poor air exchange. This method was found by these authors to be very subjective. The purpose of this study was to use a quantitative method to determine the efficiency of the ventilation system throughout rooms. A particle generator and laser particle counter were used in isolation rooms to measure effective ventilation rates. Particles were released and fans were used to induce good mixing of the particles throughout a room. Fans were shut off and the concentration decay of 1.0 µm particles was measured in at multiple locations. The decay curve, the mechanical ventilation rate, and the room volume were used to determine the effective ventilation rates at the various locations. Effective ventilation rates varied over threefold within a given room. The effective ventilation rate at a location seems to be associated with the relative position of air supply diffusers, other air entrance points, and the air return. This information can be useful in isolation room design planning and in describing the protection afforded by general ventilation at various locations in rooms.
C. Lai, C. Chiang, Chung Shan Medical University, Taichung, Taiwan Republic of China; W. Lin, China Medical University, Taichung, Taiwan Republic of China; T. Yu, Y. Ho, C. Chang, Institute of Occupational Safety and Health, Council of Labor Affairs, Taipei, Taiwan Republic of China.
Respiratory protection filters will affect human beings and environments once loading of airborne fungi and pathogen in highly temperature and humidity atmosphere. For instance, the filtration quality of personal respiratory protection filters will reduce if there is continuing contact with human perspiration or other secretions. Moreover, the pathogen, fungi, and molds will grow on the filter media under the presence of sufficient temperature, moisture, and nutrients, especially when the filter media are frequently used and are not disposable. In this study, the personal N95 respirator filters were tested for the survival rate of bacteria. The operation parameters include the variability of temperature and humidity in growing bacteria under different storage conditions and nutrients. A Collison nebulizer was used to generate B. subtilis spores and E. coli. Sterilized water, artificial saliva, and artificial perspiration were used as the nutrients in growing bacteria. A single-stage Andersen sampler was used to sample bacteria for measuring aerosol concentration. The ultimate goal of this study will provide recommendations of filter storage conditions. The results show that both B. subtilis and E. coli were found to survive on the personal N95 respirator filters, especially under 95% moisture and 35°C incubation temperature conditions. The viable bacteria may pose risk when reused respirators are not carefully handled and stored.
S. Cali, University of Illinois at Chicago, Chicago, IL; S. Fridkin, T. Clark, G. Huhn, M. Arduino, M. Brandt, R. Hajjeh, D. Warnock, CDC, Atlanta, GA; C. Conover, llinois Department of Public Health, Chicago, IL.
A cluster of four cases of a rare fungal infection occurred in a dialysis clinic. The fungus was preliminarily identified as Phialemonium curvatum in clinical samples from the patients. Only six cases of infection by this organism had been previously described in literature. No environmental sources of the organism were previously described. A multidisciplinary investigation was initiated that included chart and patient treatment protocol review, a case-control epidemiology study, and environmental sampling. The investigation was confounded because little was known about the organism, the latency period of disease, or appropriate sampling and culturing techniques. In addition, the apparent onset of the infections had occurred over a period of time during which the clinic was relocated to a different floor in the same building, all of the dialysis machines were replaced, and certain procedures were changed. The environmental sampling initially targeted water, dialysate fluids, and selected surfaces of instruments and ventilation ducts in the current and previous clinic locations. Although visible fungi and potential sources were found in the original clinic location, no target organisms were cultured from approximately 70 fluid and surface samples collected at both clinic locations. The investigation was widened to include nonclinic areas. Eventually, Phialemonium species were recovered from two samples collected in two air-handling units that served both clinic locations. The internal transcribed spacer sequences of these isolates were identical to each other and to the patient isolates, indicating the HVAC system as a likely source or reservoir. Corrective recommendations were made and no new infections have occurred. The apparent mode of exposure is not clear, but it is possible that entrainment of the organism in the ventilation system led to contamination of skin puncture sites, treatment materials, tools, or fluids.
Posted May 30, 2006