Institute of Medicine Response
Response to the OSHA TB Standard
a letter written by John H. Keene, Dr.PH, CBSP (ABSA)
President, American Biological Safety Association
29 July 2000
July 29, 2000
Marilyn J. Field, Ph.D.
Institute of Medicine
2101 Constitution Avenue, N.W.
Dear Dr. Field,
The American Biological Safety Association (ABSA) appreciates your invitation to provide comments to the Institute of Medicine regarding its short-term study of occupational exposure to tuberculosis (TB). The American Biological Safety Association (ABSA) is an international group of biological safety professionals and is known as the world's foremost resource on biological safety practices and procedures. One of our major organizational goal is to minimize potential occupational exposures to biological hazards. We are responding to your specific questions as follows:
From your organization's perspective, what are the strengths and limitations of relying upon CDC guidelines versus an OSHA rule? What additional benefits or harms would likely result from adoption of an OSHA rule?
Although the Centers for Disease Control and Prevention (CDC) published revised TB prevention guidelines on October 28, 1994, the emphasis of that document was on patient care. In the laboratory work environment, CDC does have an agent summary statement for TB in its 4th edition of the CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL). The BMBL provides good guidelines for work with TB cultures or preparation of acid fast smears in microbiology laboratories. However, there are a number of other laboratory operations with exposure potential that pose occupational risks that are not addressed. An example of such operations is preparation of sputum for cytology. The mycobacterium which causes TB is found most frequently in sputum. The growth of managed care in the heath care system has meant that more testing, including sputum cyto-prep, is done in fewer locations. Therefore, cytologists working in these facilities are at increased risk of occupational exposure to TB.
The CDC Guidelines have given us an industry standard, and, as such, are considered mandatory in the healthcare community. Generally, certifying agencies (JCAHO and CAP) have used the CDC guidelines in their inspections. We would present two suggestions that may be worthwhile:
a. If an OSHA standard is adopted, collaboration with other certification agencies, such as JCAHO and CAP, would be helpful, from the interpretation point of view for both the healthcare facilities and the OSHA compliance officers.
b. There are at least 3 CDC Guidelines that specifically address protection of workers and the environment from exposure to TB: the 1994 CDC Guidelines for Healthcare Facilities, the 4th edition CDC/NIH Guidelines for Laboratories, and the Proposed Goals for Working Safely with Mycobacterium tuberculosis in Clinical, Public Health, and Research Laboratories. In addition, the agent summary statement for work with M. tuberculosis is presented in the 4th edition of Biosafety in Microbiological and Biomedical Laboratories. These documents need to be reviewed and a consensus drawn for consistency for inclusion in any OSHA standard.
OSHA standards are often not flexible enough to apply to the wide variety of work practices found in the health care setting. Any OSHA standard on occupational exposure to TB should be "performance based", as is the Bloodborne Pathogens Standard, in order to allow for variations in work practices throughout the health care industry.
The CDC guidelines and the proposed OSHA rule are similar in most respects. What specific differences between the CDC guidelines and the proposed OSHA rule would most likely bring benefits or cause problems?
The proposed OSHA standard, as written, establishes baseline facility and work practices requirements for both clinical and research laboratories which culture the TB organism. It provides additional requirements for research laboratories. OSHA is assuming that the hazards associated with working with TB will be greater in the research laboratory because the organism is known and being investigated. The reality is that many of the same procedures may be done in the clinical laboratory after the organism is identified. After a positive acid fast smear, the organism may be cultured in order to speciate and to perform drug susceptibility testing. There is no difference in the hazards regardless of where the organism is being cultured.
Because the performance of initial diagnostic acid fast smears does not constitute the same type of aerosolized infectious hazard as does culturing, this procedure should be allowed to be conducted at Biosafety Level 2 in a properly certified class II biological safety cabinet. This would allow for more prompt, efficacious and cost-effective initial diagnosis and treatment of TB cases without compromising occupational safety and health and public health.
OSHA is also leaving the decision as to the appropriate biosafety level up to the laboratory director. Given the conflicts detailed above, there would be a lot of confusion and inconsistent judgments. The 4th edition of the BMBL is proscriptive of the type of containment that is needed for manipulations of TB specimens. In the case of the laboratory work environment, OSHA needs to more effectively embrace the requirements in the TB agent summary in the BMBL. The 4th edition of the BMBL had not been released when OSHA issued its TB proposal, and that may account for some of these differences.
Medical surveillance requirements for health care workers such as phlebotomists and respiratory therapists have been detailed in the CDC recommendations. However, there are many of these health care workers who may have to go to a facility such as a long term care facility or correctional facility in order to render patient care. Although all of these facilities may not treat diagnosed TB patients, they do service populations which have a high prevalence of this disease. Medical surveillance requirements for health care workers who must go to such facilities but which do not have patients with active TB disease are not detailed. Medical Surveillance of all employees and contractors with direct patient contact should be mandated.
What additional areas of research and data collection would help policy makers, managers, and others improve polices and procedures to protect workers from occupational exposure to tuberculosis?
Laboratory acquired infections are likely under-reported. The Office of Biosafety in Canada has taken a step towards capturing more of this vital information in Canada. Canada is setting up a web-based reporting system for these types of exposures. This system will enable the anonymous reporting of laboratory acquired infections and will include information on the agent causing the infection, the type of accident (if any) preceding the infection, the route of exposure, the type of laboratory, and the occupational group of the individual who contracted the infection. The data generated will be used to develop standards and guidelines which are based on hard fact versus projections.
CDC has developed a program for the confidential reporting and tracking of health care worker exposures to human immunodeficiency virus (HIV). There is, therefore a United States precedent for the gathering of confidential information regarding occupational exposures. CDC could emulate the Canadian Office of Biosafety and establish an anonymous laboratory-acquired infection reporting system in the United States. It would help to provide a better foundation in dealing with laboratory exposures to TB and other occupationally-acquired infectious diseases. Such a surveillance system should be expanded to cover all workers potentially exposed to TB. The CDC already has a system (National Surveillance System for Hospital Health Care Workers, i.e., "NaSH") which has a component for TB skin testing results and follow-up for healthcare workers. This system could be utilized to gain more meaningful data for risk of TB infection in health care and laboratory workers. This is essential as a monitor for any guidelines or standards.
A potential negative effect from adoption of an OSHA rule for tuberculosis control would be a standard with requirements based on non-existent or scarce data. Specifically, a requirement for 100% compliance with the use of fit-tested respirators, particularly if an annual re-test is required. This would place a large, unsubstantiated management and cost burden on healthcare facilities as well as laboratories. More research is needed regarding the effect of fit-tested respirators vs. non-fit-tested respirators on skin test conversions (i.e., infection) of employees.
In addition, while specific recommendations are made on ventilation rates, directional airflow and filtration in the CDC guidelines, and the compliance with these recommendations is required by OSHA, no data is offered which quantifies the numbers of Mycobacterium tuberculosis present in an isolation room housing a patient with active TB. Compliance with these empirically based recommendations can be expensive and should be justified by peer reviewed research on the quantification of the potential for exposure.
Finally, the educational component of the Guidelines should be emphasized and mandated, particularly for the frontline workers. At one institution, the rates of skin test conversions in employees dropped from between 1-2% from 1993-1995 to between 0-0.5% from 1996-1999, when mandatory TB education and awareness for all employees, including house staff and attending physicians had been instituted. Appropriate training should include the basics of symptoms and epidemiology of TB disease, the high risk groups for TB infection, as well as the control procedures. At healthcare institutions, those occupational groups with triage responsibilities are at highest risk of TB skin test conversions (i.e., physicians (especially residents and interns), nurses) who have exposures before TB is even suspected. Information to assist in identification of the high risk groups and TB symptoms is essential to initiate proper isolation of the patient, as well as collection and labeling of laboratory specimens.
Thank you for this opportunity to provide our input on this topic. ABSA and its members stand ready to assist you in any way in the final development of your report. Please feel free to contact our office at any time.
John H. Keene, Dr.P.H., RBP, CBSP (ABSA)
American Biological Safety Association
John H. Keene, Institute of Medicine Response - Response to the OSHA TB Standard, American Biological Safety Association (29 July 2000),