Biosafety Issues in Hospital Settings
Biosafety Issues in Hospital Settings.
Dr Richard Gilpin RBP CBSP. Assistant Professor of Medicine. Assistant Professor of Environmental Health Sciences. Biosafety Officer, Biosafety Division, Office of Health, Safety & Environment. The Johns Hopkins Institutions. Baltimore MD.
Chapter 4. “In,” Jonathan K. Richmond, PhD, Editor. Anthology of Biosafety: III. Application of Principles. 2000. American Biological Safety Association.
Note: This chapter was published in 2000. Hyperlinks and some practices and procedures have changed.
Paper at ResearchGate:
Abstract. Federal and state regulations with a hospital biosafety component have increased dramatically during the 1990’s. The need for biological safety individuals that have hospital experience are greater today than ever before. This chapter covers many hospital-related biosafety issues, both administrative and by topic. This is a description of how biosafety functions are organized and implemented at Johns Hopkins Institutions, with observations regarding the mounting of a successful biosafety program.
Table of Contents . Biosafety Functions. Biosafety Related Advisory and Regulatory Organizations. Biosafety Related Administrative Programs. Personal Protective Equipment. Biosafety Interactions with Administrative Units. Biosafety Related Hospital Committees. Summary. References.
Biosafety Functions. Biosafety in hospital settings involves protection of employees from infection by biohazardous materials that may be transmitted from patients, patient equipment, and the hospital environment. Biohazardous materials are microorganisms or their products that can cause disease in humans or animals. Policies and procedures are developed to reduce employee exposures to biohazardous materials. Employee practices, personal protective equipment, administrative controls, engineering controls, training, and medical surveillance are components of a hospital biosafety program. While the protection of patients is a function of infection control, inevitable overlap brings biosafety into these issues as well.
Administrative Reporting Level. An integrated hospital reporting structure for safety operations provides the basis for biosafety implementation. The biosafety officer should report directly to an executive, often a physician, responsible for all employee health and safety programs including employee health, employee assistance, occupational injury (workers’ compensation), and occupational medicine.
The biosafety, industrial hygiene, radiation, and traditional safety (accident investigation, fire safety, and life safety) officers should report to one individual. This individual and the hospital epidemiologist should report to the head of medical affairs in the hospital to provide coordination between patient and employee safety and health program elements. Johns Hopkins Hospital has a university physician medical staff. Appointing the executive responsible for hospital health and safety to the faculty of the university with administrative reporting to a senior executive of the academic administration provides coordination between hospital and university safety programs.
Some university teaching hospitals have an individual in charge of all safety divisions reporting to the executive responsible for employee health and safety. This reduces the number of individuals directly reporting to the executive and may ensure more coordination between the four safety divisions (biosafety, industrial hygiene, radiation control, and traditional safety.
Private teaching hospitals with university physicians benefit from a joint health and safety program coordinated by one administrative unit that employs both hospital and university staff members. Such is the case at the Johns Hopkins Hospital, which is staffed by physicians that are Johns Hopkins University employees. The administrative programs of the hospital and the School of Medicine are coordinated by an administrative arrangement named Johns Hopkins Medicine. The Department of Health, Safety and Environment has served the hospital and all schools of the university for over two decades, resulting in a well coordinated, cost effective program. The hospital has its own policies as does the university. Safety policies, however, are written so that they are the same. This safety administrative arrangement uses the name Johns Hopkins Institutions Office of Health, Safety and Environment.
Hospitals without a university association may not have such an extensive program. However, many hospitals do have affiliations with physician groups and private or public healthcare maintenance corporations that may form a coordinated health and safety program with consistent policies and procedures. This is beneficial because there is less confusion over safety policies and procedures when employees transfer between hospital administrative units or physician group practices.
Relationship to Infection Control Programs. Biosafety policies and programs for hospital employees need to be intimately coordinated with patient-related infection control issues, including tuberculosis control, bloodborne pathogens, waste disposal, disinfection, microbial air sampling, and medical surveillance.
The biosafety staff should form a collegial working relationship with the hospital epidemiologist and the infection control nurses because many hospital procedures to control transmission of pathogens between patients also involve employee health issues. The biosafety officer should be a member of the hospital infection control committee, new product committee, and hospital safety committee.
The hospital safety committee has representation from the medical staff, nursing, infection control, clinical engineering, facilities, safety, legal affairs, human resources, security, materials management, employee health, and occupational injury. This ensures that appropriate hospital functional units have the opportunity to discuss and participate in decisions that affect both patient and employee health and safety programs.
Advisory Functions. The biosafety division advises line managers in nursing, clinical departments, facilities operations, housekeeping (environmental services), and hospital administration. This is an appropriate method to effect change and provide regulatory and technical information that may not be readily available to line managers.
Hospital administrative units may request advice before making policy decisions that have a biosafety-related component. For example, implementation of effective bloodborne pathogen control, tuberculosis control, and construction and renovation programs benefit from input by biosafety and other safety divisions. Hospital staff request biosafety advice related to selection of personal protective equipment, such as gloves and gowns, and selection of engineering controls such as sharps containers and waste disposal containers.
Biosafety information is communicated in weekly newsletters or newspapers, printed brochures, policy manuals, email broadcasts, an intranet web site, and individual or group training sessions. Sometimes biosafety information is presented to hospital line managers who in turn disseminate the information to their staff.
Advisory and training interactions with hospital staff have a public relations component. Care is taken to present advice and information to hospital staff at an appropriate educational level. For example, housekeeping staff and physicians relate differently to biosafety training information during question and answer sessions.
Biosafety staff should become familiar with hospital procedures, nursing practices and clinical equipment so that they can relate better to hospital audiences. Previous work experience on hospital inpatient units is helpful. Many employee safety and health interactions by biosafety staff are closely aligned with techniques used by sales and marketing professionals, such as good listening skills, avoiding arguments, gaining credibility with an audience, and good oral and written communication skills.
Line Management Functions. Large hospitals, tertiary care teaching hospitals in particular, may directly involve biosafety staff in line management functions. Some of these functions at Johns Hopkins Institutions are discussed below.
Service Functions. The certification, decontamination, and repair of all high efficiency particulate air (HEPA) filter-containing equipment is performed by biosafety staff. This function was recently brought in-house after twenty-five years of supervising outside certification contractors. This saves the institution one hundred thousand dollars per year. The biosafety staff maintain eight hundred and thirty-four biological safety cabinets and clean air benches, eighty-two powered air-purifying personal respirators (PAPRs), twenty-eight portable HEPA filtration units, and thirty-two bag-in bag-out rooftop HEPA filter units. The biosafety division certification supervisor is an accredited National Sanitation Foundation field certifier (NSF, 1999). The biosafety staff coordinate accounting and service functions directly with line managers. This service involves equipment database management, sending out annual certification reminders to HEPA equipment owners, making appointments, and receiving payment for certifications, decontaminations, and repairs of HEPA filter containing equipment.
Training and Education. The biosafety staff present regularly scheduled training sessions covering subjects such as bloodborne pathogens, tuberculosis control, packaging and shipping of infectious substances and diagnostic specimens, and occasionally sessions on the proper use of biological safety cabinets, aseptic technique, laboratory practices, and design of containment facilities. Hospital functional units often request unit-specific biosafety training. This training is often related to regulatory requirements, such as bloodborne pathogens and tuberculosis control programs.
Functional units requesting training include support associates (nursing aides), facilities, housekeeping, physician credentialing (risk management), clinical laboratories, clinical engineering, clinical trial units, materials management, security, selected nursing units, and physician groups.
Surveys. Hospital safety surveys performed by biosafety staff or a trained safety officer are taken seriously by the hospital administration. The surveys are used to tabulate information for Joint Commission on the Accreditation of Hospitals (JCAHO) Environment of Care surveys. The functional units send a representative to the surveys so line management issues can be handled on the spot. A representative from hospital facilities also participates in these surveys so that facility safety issues will be addressed promptly.
In 1989 the hospital had seventy-two clinical unit laboratories located in nursing unit soiled utility rooms. Gram stain racks and reagents, urine centrifuges, and microhematocrit centrifuges were located in these unit laboratories. Most of these unit laboratories were closed because quality control of test results was not well documented. STAT testing was moved to a twenty-four hour, centralized clinical laboratory. Closing most clinical unit laboratories reduced the biosafety staff time devoted to hospital laboratory surveys.
Record Keeping. In 1989 a database system was built to maintain safety survey and training records at Johns Hopkins Institutions. The safety database was expanded in 1992 to include employee health data. Thus enhancing the coordination between the employee health clinic, occupational injury clinic, and safety training activities. Functional unit administrators receive regular updates of their employees’ attendance at safety training sessions. This relational database is routinely updated from the hospital and university mainframe computer payroll systems. This ensures accurate tracking of all employees, even when they move between functional units. The database continuously expands, fifty-seven thousand active and former employees as of 1999, because training records are maintained after employees leave Johns Hopkins Institutions.
Performance Measurement. Information on employee and functional unit compliance with safety policy and procedures is regularly sent to each administrative unit and reported to a joint hospital-university safety committee (Joint Committee for Health, Safety, and Environment). Occupational injury data is also kept in a database and reported to the joint safety committee. Occupational injury and safety incident data are used to track employee functional unit safety compliance and to identify tasks being performed that resulted in an occupational injury. The databases are used to evaluate performance by analysis of injury rates and training compliance. Quarterly and annual reviews of this information are used to determine where corrective actions are needed to health and safety programs.
Biosafety Related Advisory and Regulatory Organizations. Biosafety staff awareness of numerous guidelines and standards that apply to hospital settings enhances biosafety advice and support provided to hospital administrative units and employees. Organizations that supply hospital-related guidelines or regulatory information are described below.
ABSA. ABSA International fosters recognition of biological safety as a distinct scientific discipline, establishes a forum for exchange of information on biological safety, and provides an organization that recognizes the needs, and represents the interests of, persons in biological safety. Its web site, http://www.absa.org (as of 28 May 1999), has many biosafety documents, including the location of an independent, biosafety email subscription service. ABSA also acknowledges biological safety professionals with two registries; Registered Biological Safety Professional, and Certified Biological Safety Professional.
ACOEM. The American College of Occupational and Environmental Medicine (ACOEM) published guidelines in 1999 (Hospital Employee Health, 1999) suggesting that physicians working in employee health services should be board certified in occupational and environmental medicine and participate in relevant ongoing continuing medical education. The official version of the ACOEM guidelines is published on the internet at http://occenvmed.net (as of 26 May 1999). An understanding of state workers’ compensation laws, occupational safety and health regulations and accreditation requirements are useful to successful implementation of an employee health and safety program. The web site, http://www.acoem.org (as of 30 March 1999), provides updated information relevant to occupational medicine.
ADA. The Americans with Disabilities Act (ADA 1991) requires that job descriptions include job functions that permit pre-placement examiners to determine whether a new employee can work with hazards (biohazards in this case) with or without reasonable accommodations. This may involve medical surveillance, proper use of personal protective equipment, and appropriate engineering controls.
ACGIH. The American Conference of Governmental Industrial Hygienists (ACGIH) provides biosafety-related guidelines for indoor microbial counts as a measure of air quality. This is a good source of information on industrial hygiene and general health and safety. The web site, http://www.acgih.org (as of 30 March 1999), provides information that crosses between the disciplines of biosafety and industrial hygiene.
APIC. The Association for Professionals in Infection Control and Epidemiology (APIC) is an important source of biosafety-related information that can help biosafety staff maintain a timely dialog with Infection Control staff on issues of interest to them. The association has guidelines on standard precautions, bloodborne precautions, airborne isolation, personal protective equipment, disinfection, and engineering controls. The web site, http://www.apic.org (as of 30 March 1999), has extensive infection control information.
ASHE. The American Society for Healthcare Engineering (ASHE) of the American Hospital Association (AHA) provides information on healthcare facility management, engineering, facility design, construction, safety management, and regulations affecting healthcare facilities. The ASHE web site, http://www.ashe.org (as of 27 April 1999), maintains updates on topics relevant to facility and safety operations.
ASM. The American Society for Microbiology (ASM) represents twenty-four disciplines of microbiological specialization plus a division for microbiology educators. This is the oldest and largest single life science membership organization in the world. The ASM web site, https://asmusa.org (as of 26 March 1999), has many layers of microbiological information, including biological safety. The American Academy of Microbiology also administers a Specialist Microbiologist board exam in Biological Safety Microbiology.
BNA. The Bureau of National Affairs (BNA) publishes a Health Care Facilities Guide (BNA 1998) that is frequently updated as new guidelines and regulations are published. This is an excellent source of reference information for hospital biosafety staff.
CDC. The Centers for Disease Control and Prevention (CDC), an agency of the Department of Health and Human Services, has a wealth of information pertinent to hospital policies and procedures including guidelines for prevention of transmission of Mycobacterium tuberculosis in healthcare settings (CDC 1994). The CDC publishes many guidelines that are usually adopted by hospitals. The CDC also publishes a biosafety guideline for laboratories in collaboration with the National Institutes of Health. The fourth edition of the CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL) is available from the Government Printing Office (CDC 1999).
A Guideline for Infection Control in Health Care Personnel, published by CDC and the Hospital Infection Control Practices Committee (Bolyard 1998), updates and replaces previous editions. This guideline provides biosafety staff with information ranging from employee health clinic management and policies to the epidemiology of infections transmitted to healthcare workers, and how to effectively prevent these transmissions.
Biosafety practitioners should subscribe to the CDC Morbidity and Mortality Weekly Report either by email or traditional mail. These reports are often the first place that public health professionals and health care workers can receive factual biosafety information about infectious disease outbreaks, characteristics of microbial pathogens, and guidelines for handling these pathogens in clinical and laboratory environments.
DOT/ICAO. The Department of Transportation (DOT) shipping regulations, with proposed changes (DOT 1998), and the international dangerous goods regulations published by the International Civil Air Organisation (ICAO) are being enforced more stringently than ever. The IATA Dangerous Goods Regulations, published by the International Air Transportation Association (IATA 1999) every January, provides a quick reference to these regulations. Regulators are paying more attention to how hospitals and clinics package and ship infectious substances, diagnostic specimens and chemicals such as formalin, ethanol, dry ice, etc. Shippers must declare all dangerous goods and other regulated materials, or face fines and criminal penalties. This awareness has increased because some private overnight shipping companies notify the DOT’s Federal Aviation Administration (FAA) when they discover any improper shipping practice. Biosafety officers need to be aware of these Dangerous Goods Regulations in order to assist hospital personnel with their shipping needs and to provide DOT shipping training.
EPA. The Environmental Protection Agency (EPA) regulates the use and disposal of chemicals, such as hospital disinfectants and pathology laboratory chemicals. Each state has statutes that meet or exceed EPA regulations for transport, treatment, storage, and disposal of hazardous materials, including chemicals and medical waste.
Although the states regulate medical waste treatment and disposal, EPA regulations are adopted by the states for the permitting of landfills, medical waste incinerators, and pathologic incinerators. The EPA web site, http://www.epa.gov (as of 26 May 1999), has a search engine that will speed up searches of a large database of information
JCAHO. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) is a predominant force in the hospital industry. The web site, http://www.jcaho.org (as of 30 March 1999), has information and links to government and professional healthcare associations and other providers of information. Biosafety-related issues are addressed in the JCAHO Environment of Care standards. The JCAHO now publishes an official newsletter covering this subject (JCAHO 1998). These standards cover areas such as safety, security, hazardous materials and waste, emergency preparedness, life safety, medical equipment, and utility systems. Biosafety staff participate in the planning and implementation of policies involved with JCAHO standards that address safety, hazardous materials, medical waste, and emergency preparedness.
The Association of Occupational Health Professionals in Healthcare has asked JCAHO to consider “stand-alone standards” specific to employee health departments. (Hospital Employee Health 1999). Topics suggested for the proposed standards include “health assessments; recognition, evaluation, and control of occupational health and safety hazards; evaluation, treatment, and case management of occupational injury and illness; surveillance, prevention, and control of infection; management of occupational health information; education; and health promotion and wellness”.
NCCLS. Hospital clinical laboratories follow guidelines and standards promulgated by the National Committee for Clinical Laboratory Standards (NCCLS). Its web site, http://www.nccls.org (as of 30 March 1999), provides information on standards developed for clinical laboratory procedures as a result of consensus among laboratorians in industry, government, and academic institutions.
NIOSH. The National Institute of Occupational Safety and Health (NIOSH), a division of the Department of Health and Human Services, reports to the CDC. This agency became more visible to the healthcare community when tuberculosis prevalence increased during the early 1990’s. NIOSH is an educational organization that funds research and training at universities. NIOSH has the technical capability to research areas of interest to the protection of employees and to develop toxicology and employee health guidelines that may become OSHA standards. NIOSH publishes a list of approved N95 and HEPA filtered respirators for use by healthcare workers entering airborne isolation rooms. Hospital biosafety staff will find the NIOSH guideline for evaluating and using sharps containers to be useful, particularly if their hospital is considering a change in sharps containers (NIOSH 1998).
Its web site, http://www.cdc.gov/niosh/homepage.html (as of 26 May 1999), is a good reference source for technical information related to biological safety.
NSC. The National Safety Council (NSC) provides traditional safety and health information applicable to hospital settings. Its web site, http://www.nsc.org (as of 31 March 1999), provides ordering information for books and manuals. The NSC has become involved in biosafety-related issues pertinent to hospitals, such as occupational safety and safety management.
NSF International. The NSF International (NSF) is a third party certifier of products and services. Its web site, http://www.nsf.org (as of 31 March 1999), is a good resource for standards and approved products relevant to hospitals. Biological safety cabinets are evaluated and listed according to NSF Standard Number 49 (NSF 1992), considered the industry standard.
OSHA. The Department of Labor, Occupational Safety and Health Administration (OSHA) increased its visibility in hospitals when the bloodborne pathogen standard was promulgated in 1991 (OSHA 1991) and the revised respiratory protection standard was published in 1998 (OSHA 1998a). Its web site, http://www.osha.gov (as of 31 March 1999), has an extensive library of standards, documents and resources. Enforcement of the bloodborne pathogens standard is either by federal OSHA inspectors or by state occupational health inspectors in OSHA-cooperating states that have an OSHA approved statute.
OSHA is now collecting injury and illness information from hospitals that may be used to determine which employers will be inspected in subsequent years. Hospitals with higher than normal injury or illness records may become a target for more frequent inspections. In 1999, OSHA inspections are in response to employee complaints.
SHEA. The Society for Healthcare Epidemiology of America (SHEA) fosters the development and application of the science of healthcare epidemiology. SHEA has published recommendations for management of health care workers infected with Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), Human Immunodeficiency Virus (HIV), or other bloodborne pathogens (SHEA 1997). This organization is a good information resource for hospital epidemiologists, infection control practitioners and biosafety professionals.
Its web site, http://www.medscape.com/Affiliates/SHEA (as of 28 May 1999), contains information about two journals published by SHEA, Infection Control and Hospital Epidemiology, and Clinical Performance and Quality Health Care.
Biosafety Related Administrative Programs.
Airborne Isolation. Airborne isolation is the term used at Johns Hopkins Hospital to designate the isolation procedure used to manage patients with known or suspected infectious Mycobacterium tuberculosis (TB) disease.
Biosafety staff involvement includes advice on the design of negative pressure isolation rooms connected to roof top bag-in bag-out exhaust HEPA filters. Biosafety staff check the performance of these filters every three months. Separate magnehelic pressure gauges across pre-filters and HEPA filters are used to measure air pressure differential, an indication of filter loading with dirt. When the pressure increase across a filter exceeds a pre-determined level, the biosafety staff replace pre-filters and also replace and certify new HEPA filters when required. Exposure risks to biosafety staff during filter removal are minimized by the bag-in bag-out procedure, and because they wear half-face HEPA cartridge, negative pressure respirators.
Biosafety staff certify and maintain powered air purifying positive air pressure HEPA respirators (PAPRs) used by hospital staff when entering airborne isolation rooms. The PAPRs are checked every month for proper airflow and repairs are made as necessary. There are seventy-two PAPRs permanently located at nursing units and procedure rooms where TB patients are treated. Additional PAPRs are available from the biosafety staff for emergency use in other hospital locations.
Biosafety staff also certify and repair portable HEPA filter units that are wheeled into airborne isolation rooms to supplement the particle dilution effect of room exhaust. The portable HEPA units are about the size of a small refrigerator and are delivered by biosafety staff to ensure that they are placed in the proper location in patient rooms, usually just inside and perpendicular to the door. There are twenty units permanently placed in areas where there is a perceived need for additional HEPA filtration, such as airborne isolation rooms and intensive care units for pediatric patients with low white blood cell counts. The portable HEPA units are checked every three months for proper airflow when the pre-filters are replaced. They are certified annually and every three years they are decontaminated so that the HEPA filters can be replaced and certified by an aerosol leak test method.
Biological Air Sampling. This subject has received much attention by hospital staff because energy conserving building construction during the 1970’s produced indoor air quality issues that were widely publicized. Therefore, this section covers microbial air sampling issues in detail.
Microbial air sampling is performed by request from industrial hygiene, infection control and functional units in the hospital. Biosafety staff use a Biotest RCS Plus centrifugal air sampler. The sampler has a microprocessor-controlled motor speed and operates on a rechargeable battery. The sampler runs for about four minutes at each sample site, a typical run time recommended by the manufacturer. Each sample collects one hundred and sixty liters of air.
Airborne fungal counts are requested more frequently than airborne bacterial counts. Requests are generally related to indoor air quality concerns including allergies. Inpatient oncology units occasionally request sampling for potentially pathogenic fungi such as Aspergillus fumigatis. One year, biosafety staff collected over three hundred and forty samples at oncology patient units and found no evidence of fungal amplification (multiplication of fungal colonies causing increased numbers of airborne fungal spores).
Only one office area was found to contain fungal counts over five hundred colony forming units per cubic meter during the last ten years. Ironically, this sample was obtained at the second floor of the former safety office.
All microbial air sampling is accompanied by a contemporaneous outside control. Generally, outside control colony forming units are an order of magnitude higher than the inside colony forming units. Usually employees conclude that the outside environment is more problematic than their inside environment when they see the control fungal counts.
Attention to the interpretation of indoor air sample counts is an important biosafety issue. Misinterpretation of results may cause unwarranted concern among employees. The significance of a few colony forming units (cfu) from indoor air samples must be compared to outdoor colony forming units because fungi enter buildings in supply air. If there is fungal amplification indoors, the colony forming units may then be greater than outdoors.
A more useful measure of airborne contamination of the indoor environment can be obtained with a recording multi-channel laser particle counter operating over an extended time period. The biosafety staff has used this method to demonstrate the significant contribution to indoor particle levels by carpeting. Carpet is now permanently removed from patient areas during renovations.
An article using a statistical approach to identify the influence of various factors on the data reproducibility and air sampling confidence limits stated that “there is no legal standard for sampling methods for airborne microorganisms” (Straja and Leonard, 1996). Also, “the sampling -period can not be long because the collection surface dries or the agar deforms beneath an impaction jet.” Straja and Leonard (1996) chose Biotest RCS equipment because of cost, commercial availability, portability, ease of operation, and inconspicuousness. They sampled for thirty seconds, sixty seconds, and one hundred and twenty seconds in the same room using forty replicate samples with four teams of sampling personnel. They presented a statistical analysis of the data and concluded that “all quantitative conclusions involving the number of colony forming units should be reached considering that their distribution is log-normal rather than normal.” Straja and Leonard (1996) stated that “Biotest RCS air-samplers seem to be reliable in the sense that different sampling-periods give practically the same information.”
Plog (1996) states that “impaction directly onto an agar-based culture medium is the most commonly chosen method to collect culturable bacteria and fungi. Hand-held, battery-operated samplers have the advantage of portability and independence from a power supply, although they sample at fairly high flow rates (forty to eighty liters per minute), these devices are quiet and fairly inconspicuous.”
The American Conference of Governmental Industrial Hygienists (ACGIH 1989) recommends that “the commercially available centrifugal impactor is quite portable and inconspicuous, thus making it an obvious choice where samples must be taken with minimal disturbance of occupants.” They state that the device cannot be calibrated mechanically, citing a 1983 article (Macher and First 1983). However, a new Biotest RCS Plus model produced in 1991 has an optional mechanical calibration device. Chatigny et al. (1989) state that there are “no widely accepted guidelines for an allowable or desirable microbiological burden in the air, and little consensus on an ‘indicator organism’ to demonstrate contamination of air in the same way that a coliform count is used to reflect water quality.”
The Environmental Health Directorate of Canada (Health Canada 1995) states that “vacuum/culture devices such as RCS, Andersen, and slit-to-agar samplers are recommended for air sampling in public buildings and that current Health Canada guidelines are based on four-minute samples with the RCS .”
Jensen et al. (1992) made an important point about the earlier model (Biotest RCS) used in their investigation. The Biotest RCS actual flow rate was experimentally determined to be two hundred and ten liters per minute by Macher and First (1983). Jensen et al. (1992) pointed out that the manufacturer’s suggested forty liters per minute flow rate be used for calculated recovery of microorganisms because the high air velocity in the centrifugal impaction chamber reduced the capture efficiency of particles smaller than four micrometers.
The new Biotest RCS Plus has a redesigned sample chamber that minimizes turbulence by separating the intake and exhaust streams via a flow-through sample port while components of the rotor assembly (impeller blade, drum, and agar strip) all rotate simultaneously, further minimizing turbulence. The RCS Plus yields a high collection efficiency for viable particles across a wide range of particle sizes and achieves an eighty-five percent efficiency for two micrometer size particles, and over ninety-eight percent efficiency for four micrometer and larger size particles.
Sample volume information from a literature review (unpublished information) indicates that use of twenty-eight liter per minute samplers run for five to fifteen minutes is the most common practice. Some investigators get around the usual sampling volume limitations by running their samplers over and over at the same location with new culture media agar strips each time. Then they incubate these multiple samples, count colonies and add all of the results together to give the colony forming units for a large, theoretical air volume sample.
Arnow et al (1991) found mean counts of two tenths per cubic meter of Aspergillus species before an outbreak among immunocompromised patients, and a mean up to two and two-tenths colony forming units per cubic meter during the epidemic period. They used a slit sampler operated at one hundred and eighty liters per minute for three minutes. Goodley et al. (1994) added sample counts obtained over a long time period and expressed the results as total colony forming units per cubic meter per month. They also found that even when the A. fumigatus counts in the air were as high as four colony forming units per cubic meter “none of the colonized patients subsequently developed infection related to Aspergillus species and none had persistent colonization.”
CDC surveillance guidelines (CDC 1997) for aspergillosis have “no recommendation for performing routine, periodic cultures of devices, air samples, dust, ventilation ducts, and filters in rooms occupied by high-risk patients.” This is an unresolved issue, according to CDC. The guidelines also recommend that if a case of nosocomial aspergillosis occurs, “collect environmental samples from potential sources of Aspergillus species, especially those sources implicated by epidemiologic investigation, by using appropriate methods (e.g., use of a high-volume air sampler rather than settle plates.” These guidelines define ‘appropriate methods’ as use of the Biotest, Andersen, and slit-to-agar samplers, which are considered high volume samplers. This is a common designation for samplers that operate in an air flow range of twenty-eight liters per minute to sixty liters per minute, with sample times ranging from a few minutes up to sixty minutes.
Some hospitals have an immediate reaction to cases of nosocomial aspergillosis and begin intensive air sampling, only to flood the clinical lab with samples and come up with no useful information. Therefore, caution is advised.
Biological Safety Cabinets. Biological safety cabinets (BSCs) are used in the hospital by the pharmacy, in-vitro fertilization clinic, procedure rooms, and clinical laboratories. BSCs should not be called “hoods” because most individuals confuse this term with chemical fume hoods. The biosafety division approves purchases of all HEPA filter-containing equipment at Johns Hopkins Institutions. Purchasing sends purchase orders to the biosafety division before purchase orders are sent.
A detailed, performance oriented biosafety cabinet specification was collaboratively written to ensure that vendors submitting bids for equipment that was listed by NSF 49 and would pass motor/blower specifications under HEPA filter loading conditions (Jack Wunder, personal communication).
Bloodborne Pathogens Control Program. Biosafety division staff involvement began in 1988 with a training seminar for hospital staff presented by the infectious disease department, biosafety division, HIV researchers, nursing department, infection control department, and hospital administrators.
Bloodborne pathogens continues to involve biosafety staff on many fronts, primarily training and education. The bloodborne pathogen control policy, training brochures, posters, written handouts, and other materials were collaboratively produced by the biosafety staff with input from employee health, occupational injury, nursing, infection control, housekeeping, and facilities.
Early training materials for the entire hospital staff consisted of a multiple page brochure that covered most program components of the policy and a forty-minute videotape produced by a video production company for Johns Hopkins Institutions.
Physician training started with a self-study brochure and a national board-style test that physicians completed and returned to the biosafety office. Occasionally, physician office staff would call to find out how they did on the test, thus explaining why some physicians scored below forty percent. Currently, the biosafety officer presents bloodborne pathogens training and policy updates during risk management seminars that are required every two years for physicians with hospital privileges.
Nursing staff training is accomplished via self-study manuals placed at all nursing stations. Nurses read these manuals, take a quiz and return it to nursing administration. Training records are then forwarded to the Office of Health, Safety and Environment for database entry.
Support associates have increased responsibility for routine patient care activities. These individuals receive bloodborne pathogen training by biosafety staff at least once a year. Training sessions involve the use of handouts, but the primary training involves a question and answer session directed toward topics that are important to support associate duties. Topics include Hepatitis B Virus (HBV) vaccination, the post exposure hotline, personal protective equipment, disinfectants, and waste disposal.
New hospital staff, including nurses, receive bloodborne pathogen training by the employee health division which gives employees the opportunity to schedule HBV vaccination, tuberculin testing, and antibody testing as appropriate.
New university staff, often assigned to hospital areas, receive information about the in-depth bloodborne pathogen training sessions presented twice every month. Employees that have potential occupational exposure to human blood, internal body fluids, unfixed tissue, human tissue cultures, or animals inoculated with human materials come to these training sessions. Training includes procedures to follow if exposed, such as washing the exposed site with soap and water or water irrigation for eye exposures, calling the employee exposure hotline, post-exposure prophylaxis for serious exposures, and confidential clinical case management after an exposure. Eight minutes of video summarizing important training elements of the policy is followed by discussions of the differences between exam and non-sterile surgical gloves for patient care and research laboratory use, respectively. Comparisons between latex, vinyl and nitrile gloves include a discussion of potential allergies from cornstarch powder in latex gloves. Question and answer sessions often deal with disinfectants, wearing gowns with knit gloves in laboratories, hazard signage, survival of bloodborne pathogens in the environment and recently, notification of packaging and shipping certification classes.
Clean Air Benches. Clean air benches (CABs) are becoming scarce in hospital settings because they offer no personal protection. Their remaining use is assembly of sterile packages for patient care. Reverse flow clean air benches are used in patient settings to deliver aerosolized medications. The patient sits at the reverse flow clean air bench during aerosol delivered medication. The HEPA filter at the rear of the clean air bench captures aerosols that escape during treatment.
Cleaning and Disinfection. The biosafety staff recently worked with infection control, nursing, housekeeping, legal affairs, and clinical engineering to replace an alkaline, benzyl ammonium chloride spray disinfectant with an organic solvent base that allegedly damaged plastic-containing clinical equipment. The decision was made to return to a one to ten dilution of household bleach for laboratories, a one to fifty dilution for clinical areas with no dispensing station, and a one to twenty dilution for areas with dispensing stations. All dilutions will have one month expiration dates. The stability these dilutions is enhanced by keeping the solutions at about pH of 8.0. A recent review of disinfectant use in hospitals provides additional background (Rutala 1996).
Cleaning is the physical removal of organic material or soil from objects. It must be accomplished with water, mechanical action, and detergents. Disinfection is the killing or inactivation of specific target microorganisms. The efficacy of disinfection is affected by a number of factors, including the type and level of microbial contamination, presence of organic material, the activity of the disinfectant, and disinfectant contact time.
Biosafety staff collaborate with infection control, nursing, housekeeping, and industrial hygiene to develop policies for routine disinfection of environmental surfaces, decontamination of blood spills, and proper use of sterilants for semi-critical and critical items.
Disinfectants are divided into three hierarchical categories of antimicrobial activity. Low-level disinfectants kill most bacteria, and some fungi, and inactivate some viruses. They do not reliably kill Mycobacterium tuberculosis or bacterial spores. Intermediate-level disinfectants kill most bacteria, including Mycobacterium tuberculosis, and most fungi. They inactivate most viruses and kill some bacterial spores. High-level disinfectants destroy or inactivate all microorganisms, including most bacterial spores.
Low level disinfectants, such as quaternary ammonium compounds, are used for non-critical items that come into contact with intact skin but not with mucous membranes; for example, blood pressure cuffs. These general purpose hospital disinfectants have hundreds of different brand names. Environmental surfaces, such as floors, walls, and tables, are usually not involved in the transmission of infections. A detergent with low-level disinfectant activity is sufficient for general cleaning of these surfaces.
Intermediate level disinfectants, such as sodium hypochlorite (household bleach), iodophores, hydrogen peroxide, and phenolics, are used on semi-critical items such as hydrotherapy tanks and thermometers. When environmental surfaces are significantly contaminated by large quantities of blood, an absorbent drape or paper towel should be placed over the contaminated material and an intermediate level disinfectant should be sprayed or poured on the drape or paper towel. After 10 minutes of exposure the drape or paper towel should be discarded, followed by more intermediate-level disinfectant applied to the surface.
High level disinfectants, such as activated 2% glutaraldehyde, are used for semi-critical items that come into contact with mucous membranes or non-intact skin. Examples of items that require high-level disinfection are respiratory therapy equipment, arthroscopes, laparoscopes, and endoscopes.
Construction and Renovation. Biosafety issues involve containment of dust, microbial spores, or other microbial material that may become airborne during construction and renovation. Biosafety staff collaborated with industrial hygiene, infection control, and facilities design and construction to develop a policy that provides dust containment when work is performed in or near patient or clinical areas.
The containment policy is similar to a typical asbestos abatement policy but without intensive air sampling. Plastic sheeting is taped to surfaces around construction areas and plastic sheet double entry systems are constructed. A HEPA filtration system is sometimes used to provide negative air pressure inside construction areas and to trap dust particles in HEPA filters. HEPA filtration is often used during construction near patient sensitive areas such as operating rooms, intensive care units, and oncology units.
A containment procedure with recommended personal protective equipment was developed for entry into supply and exhaust ductwork in patient areas and includes a list of appropriate personal protective equipment. This became an issue for oncology and transplant patient areas with built in HEPA filtered air systems above dropped ceiling tiles. When a patient room HEPA filter or blower fan must be replaced or cable must be pulled above dropped ceilings, plastic containment is built around the repair area.
Employee Health Management. Biosafety staff coordinate training information with the employee health clinic and the occupational injury clinic to ensure accurate health information is delivered to employees. Biosafety related information is reviewed by employee health and biosafety staff.
Employees learn about the employee health clinic location and office hours during orientation. The clinic typically handles vaccinations, tuberculin skin tests, respirator medical surveillance, confidential antibody testing for bloodborne pathogens, and other medical surveillance. The clinic has several waiting rooms, examination rooms, and treatment rooms.
Eye, Face and Body Wash. A drench hose with a spray head that produces an aerated spray six inches high is located at most sinks in laboratories and soiled utility rooms. This eye, face and body wash unit has a vacuum breaker and a cold potable water flow control valve. New laboratory areas are also fitted with a double head eyewash station connected to potable water lines.
Hand washing and Antisepsis. Biosafety issues include transmission of microorganisms to and from hospital staff. Nursing and infection control departments provide hand washing information with self-study packets. This information is included in biosafety training for bloodborne pathogens.
Routine hand washing in patient care areas utilizes an antiseptic chlorhexidine gluconate soap. Other hospital areas and laboratories utilize a mild lotion soap. Foam alcohol or germicidal hand rinse is used for waterless hand cleaning.
HEPA Filter Certification and Maintenance.
The biosafety staff certify, decontaminate, and repair all biological safety cabinets (BSCs) and clean air benches (CABs). According to policy, all HEPA-filter containing equipment must be certified at least annually. Pharmacy equipment is certified every six months. Functional unit directors are notified by memorandum when their equipment is due for certification.
Each functional unit pays for replacement ultraviolet (UV) germicidal lamps, and are responsible for discarding UV lamps at chemical waste drop off areas. Routine certifications and decontaminations are scheduled at least two weeks in advance. Highest service priority is assigned to repair of non-functioning units, followed by fluorescent and UV lamp replacement, decontamination, filter changes, and certification.
Isolation Rooms. The CDC TB Guidelines (CDC 1994) caused most hospitals to renovate existing patient rooms or construct new rooms with a negative air flow with respect to surrounding areas. Most airborne isolation rooms at Johns Hopkins Hospital have bag-in bag-out HEPA filter systems on isolation room exhausts. Isolation rooms were placed in the emergency department, medical inpatient floors, pediatric and adult intensive care units, and bronchoscopy suites.
These rooms have an air pressure sensor that alarms when the negative pressure differential is less than 0.002 inches of water pressure. Since many isolation rooms have large sliding doors to allow passage of hospital beds, the alarms sound every time the door is opened and negative pressure is lost. Clinical staff often turn off the audible alarm when they need to go in and out of these isolation rooms. Room pressure sensing systems do not provide assurance of negative air flow as efficiently as a visible indicator such as a ribbon or yarn telltale mounted in the isolation room door. Directional air flow is actually facilitated by permitting some air from the hall to infiltrate into the isolation room.
Latex Hypersensitivity. An excellent review of latex glove manufacturing, the clinical signs and symptoms of latex allergy, and management of latex allergies was recently published (Yunginger 1998).
A study of the prevalence of latex sensitization among one hundred and sixty-eight anesthesiologists and nurse anesthetists found 2.4 % of the individuals had latex allergy with clinical symptoms and 10.1% had latex sensitization without clinical symptoms. Therefore, “hospital employees may be sensitized to latex even in the absence of perceived latex allergy symptoms” (Brown et al 1998). Powdered latex gloves contain latex allergens attached to cornstarch powder. A clinical test involving puncturing of the skin on the hand immediately prior to glove application was shown to provide an objective biologic measurement of latex allergen sensitization in latex-allergic subjects (Hamilton and Adkinson 1997).
Use of powdered gloves has been curtailed in all hospital areas except for some surgical procedures. The hospital recently switched from latex to vinyl examination gloves on patient care units to reduce the probability of latex allergies among patients and healthcare workers. Latex balloons and toys are not permitted in the hospital.
Medical Waste Containers. Patient rooms have red bag lined wastebaskets. Soiled utility rooms and laboratories also have red bag lined biohazard boxes for disposal of glass, hard plastic items, closed sharps containers, and other medical waste. Clinical laboratories have larger bench top and floor plastic disposal containers with drop through holes in the top for discarding larger sharps. Cultures of microorganisms are decontaminated by autoclave before disposal into the medical waste stream.
The Johns Hopkins Hospital patient area sharps containers were recently changed from a direct drop in design to a mailbox design that closes automatically when the container is full. Injuries associated with sharps disposal into these new containers will be tracked to determine whether they are safer than the previous drop in style sharps containers. Mailbox sharps containers are less useful than drop in styles for disposal of butterfly needles and tubing, very long needles, and pasteur pipettes because these objects must be manipulated in order to fit them into a mailbox opening sharps container. NIOSH published a useful guide to sharps containers including such details as how they should be mounted (NIOSH 1998).
All red bag and boxed medical waste is trucked to a local medical waste incinerator. The State of Maryland medical waste statute requires that all medical waste be decontaminated and rendered unrecognizable before it can be landfilled.
Needle-less IV Systems. Needlestick prevention has become a topic of interest recently to regulators such as the FDA, NIOSH, OSHA, and professional associations such as APIC. Needle-less systems are recommended for non-skin puncturing procedures. OSHA has received responses from a request for information (OSHA 1998b) on engineering and work practice controls used to eliminate or minimize the risk of occupational exposure to bloodborne pathogens due to percutaneous injuries from contaminated sharps (OSHA 1999a). Based on the responses, OSHA plans to revise the record keeping rule so that all injuries from contaminated needle and sharps are recorded on OSHA logs. They will also revise the bloodborne pathogens compliance directive to reflect available safer technologies. Needlestick and sharps injuries are expected to be on the OSHA regulatory agenda for late 1999.
Occupational Injury Management. The Johns Hopkins Hospital implemented a needle stick hotline for bloodborne pathogen exposures in 1990. After a slow start, healthcare workers call the hotline with increasing frequency each year. The hotline is manned by an occupational medicine physician or physician’s assistant during business hours, and by infectious disease fellows on call at other times. The hotline exposure reporting frequency increased with publication of CDC guidelines for post exposure prophylaxis in 1996 (CDC 1996) and increased again when the CDC published the second edition of the guidelines (CDC 1998).
The hospital’s twenty-four hour pharmacy dispenses the first dose of prophylactic drugs if the exposure is considered serious and the healthcare worker decides to start the twenty-eight day course of antiviral therapy. Healthcare workers of childbearing age are given a pregnancy test before they can start post exposure prophylaxis.
Biosafety staff investigate employee incidents such as exposures related to waste disposal, handling of sharps, handling of patient specimens, and unsafe practices with clinical and laboratory equipment.
Permanent HEPA Filtration. There is a trend to provide HEPA filtered supply air in oncology and transplant patient rooms. The biosafety division assists with the proper placement of HEPA filter units. For example, HEPA filters for patient room supply air should be mounted in the ceiling of each patient room. The filter units should be designed so that they can be dropped down and replaced inside a patient room, thus minimizing the spread of dust and debris generated during filter replacement to adjacent areas.
HEPA filters should be connected directly to each room’s supply air duct. Room air should be single pass and exhausted to the outside without recirculation. Some situations may require that the supply air be mixed with some recirculating exhaust air from the same room to reduce the costs associated with heating and cooling outside air.
HEPA filters should be bench tested for leaks in the filter media and around the edges of the filter frame before the filters are mounted in the ceiling and placed into service. There have been instances of new HEPA filters with leaks around the frame or the media put into service at some healthcare facilities. Filter leaks can be found using equipment recommended by the NSH Standard 49 procedure (NSF 1992).
Portable HEPA Filtration. Johns Hopkins University designed portable HEPA filters (Tepper et al. 1993) are moved to appropriate places by biosafety staff. Portable HEPA filter units are used in two different hospital areas. They are used in patient rooms for airborne isolation when negative pressure HEPA filtered exhaust rooms are not available. They are also placed in pediatric intensive care rooms for patients with a low white blood cell count and therefore may benefit from a reduced airborne dust in their room.
Portable HEPA units are permanently located at nursing units that use them constantly and in areas such as emergency waiting rooms to provide additional removal of particulates.
Before they were used, the portable HEPA units were evaluated by industrial hygiene staff in patient rooms with an aerosol generator and particle counter to ensure that the units provided increased relative air changes in patient rooms, and effectively removed aerosolized particles. Tests with smaller, commercially available portable HEPA units often did not effectively remove particles from patient rooms. Therefore, hospitals should perform in place testing with a particle counter before portable HEPA units are placed into service.
Pre-filters on these portable HEPA filter units are replaced every three months by biosafety staff. This greatly extends the life of the HEPA filters, which usually last for two to three years of continuous operation. The airflow output of each portable unit is also checked with a hot wire anemometer. When the airflow becomes less than eighty percent of the manufacturer’s specified air velocity, the unit is placed in a plastic bag, decontaminated with formaldehyde gas, and new HEPA filters are installed. Newly installed HEPA filters are checked for leaks using an aerosol generator and a photometer (the same equipment used to certify biological safety cabinets).
Respirators. Healthcare workers entering TB patient airborne isolation rooms must wear a respirator to reduce the possibility of occupational infection from aerosolized TB bacteria. Respirator options for healthcare workers entering airborne isolation rooms was studied by the industrial hygiene and biosafety divisions at Johns Hopkins Institutions (Schaefer 1997). Industrial hygiene and nursing staff evaluated disposable respirators, reusable cartridge respirators, and positive air pressure respirators. Cost considerations and acceptance by healthcare workers clearly favored the use of loose-fitting, portable powered air purifying personal HEPA filter respirators (PAPRs). The annual cost savings was significant because a less rigorous respiratory surveillance program could be implemented. Fit checking was eliminated because the PAPRs were positive pressure and loose fitting. The medical staff found the PAPRs more comfortable to wear and more acceptable to patients than negative pressure N95 or HEPA cartridge respirators. Acceptance of these respirators was enhanced by support from the Chief of the Infectious Disease Department.
Respiratory Surveillance. Industrial hygiene staff fit test negative pressure respirators for employees. The employee health clinic manages the annual medical respiratory surveillance. Biosafety staff train healthcare workers that wear portable powered air purifying personal HEPA respirators (PAPRs) when entering airborne isolation patient rooms. A short version of the respiratory protection approval form was developed for these PAPR-wearing employees because loose fitting, positive pressure respirators with no breathing resistance have fewer medical issues.
Safer Sharps. The Food and Drug Administration (FDA), NIOSH, and OSHA jointly published a safety advisory about potential risks from small glass capillary tubes (OSHA 1999b). Accidental injuries occur when the capillary tubes are sealed with putty before they are placed into a centrifuge to determine a patient’s blood hematocrit. OSHA estimates that there are two thousand, eight hundred injuries each year from glass capillary tube breakage. The agencies recommend that capillary tubes be made of materials other than glass, that glass tubes be wrapped in a puncture resistant film, or an alternative method be used to measure hematocrit levels. Johns Hopkins Hospital changed to a colorimetric method to measure hematocrit levels in 1994 because of the possibility of injury from the microhematocrit centrifugation procedure.
OSHA and several states are in the process of adopting, regulations to increase the use of retractable needles. Early prototypes and commercially available systems were often not easy to use and sometimes did not work. Current systems are markedly improved. They are now available in many different needle-syringe combinations, either empty or pre-filled with appropriate drugs or materials. There are also retractable needle phlebotomy systems for vacuum blood tubes used to obtain blood specimens. The state of California passed a safer sharps law in 1998. Similar laws are being considered in eleven other states, including Maryland.
Signage. The hazard warning signage system developed by the safety office in the 1970’s for research and clinical laboratories was revised in 1995. The system was developed to bring uniformity to hazard warning signage used at Johns Hopkins Hospital and University.
This section will only cover biosafety-related signage used at the hospital. Hazard warning signage informs personnel and visitors that a hazard exists in an area. Two levels of risk have been established. The degree of hazard is indicated by the admission instructions on a ten inch by ten inch yellow placard mounted on the wall adjacent to the entrance of a posted area. Specific hazards are identified by two inch by two and a half inch symbols and/or hazard warnings affixed to the placard.
The levels of risk are defined on the admittance placards. “CAUTION ADMITTANCE TO AUTHORIZED PERSONNEL ONLY” placards indicate that visitors and personnel not assigned to the area must secure permission to enter from the investigator, supervisor or administrator in charge of the area. “CAUTION RESTRICTED AREA ADMITTANCE TO AUTHORIZED PERSONNEL ONLY” placards indicate that admittance is forbidden to all except those assigned to the area unless accompanied by the principal investigator, supervisor or administrator in charge of the area.
Text accompanying the labels specifies the conditions under which the most frequently used biohazard warning signs will be posted. It is the responsibility of the biosafety staff to determine the need for biohazard warning(s). The safety office posts the signage and maintains records of posted areas. It remains the responsibility of each hospital functional unit to list the names with work and home telephone numbers of two individuals on the admittance placard as emergency contacts. The individuals listed must have some familiarity with the biohazards in the posted location.
Biohazard warning labels listed with the “restricted area” text signifies admittance to laboratory personnel only, all others must obtain permission from the laboratory supervisor to enter the area or open containment equipment labeled as “restricted”. This label is generally used to identify refrigerators, incubators, and cabinets where biological agents or materials are stored.
The biohazard symbol warning label without a specific hazard description is a general biohazard warning to be used where there are multiple biological hazards, where biological wastes are stored, and for mixed biological waste containers.
Biohazard warning labels with the “potentially infectious materials ” text are used in rooms or areas (research and clinical laboratories, certain hospital unit laboratories and utility rooms) where human body fluids, unfixed cell tissue or organ cultures are handled for research, diagnosis, or shipment, and equipment used for research or diagnosis with specimens containing potentially infectious materials.
The biohazard symbol warning label with the “infectious agents” text is used in laboratories and support areas where viral, bacterial, fungal, and parasitic agents requiring containment at Biosafety Level 2 (BL-2) or greater are used or stored.
The Biosafety Level 2 (BL-2) label, with the appropriate biohazard warning label described above, designates a containment level which meets the guidelines for BL-2 work practices, safety equipment and facility design. This label is placed at clinical laboratories that process blood and other patient specimens.
The Biosafety Level 3 (BL-3) label, with the appropriate biohazard warning label described above, designates a containment level which meets the guidelines for BL-3 work practices, safety equipment, and facility design. This label is placed on the wall next to door of the clinical mycobacteriology laboratory.
A “no food and drink” label indicates that eating, drinking, smoking, handling of contact lenses and applying cosmetics are not permitted in the posted work area because there is reasonable likelihood of exposure to hazardous chemicals, radioactive materials, or potentially infectious materials.
An “eye protection required” label is posted in all areas where there is a reasonable probability of exposure by splash or spray to hazardous chemicals or potentially infectious agents and physical hazards which could cause injury.
A “protective clothing required” label is posted when work conditions require specific protective clothing which is beyond the standard laboratory coat or gown. Personal protective clothing selected for this work area shall be based on an evaluation of the task specific conditions and the hazards and potential hazards that are encountered.
Standard Precautions. Standard Precautions supplanted Universal Precautions at most hospitals following recommendations by healthcare professional associations (Garner 1996). Portions of the Johns Hopkins Hospital policy, developed by collaboration of biosafety, infection control, and nursing are presented for informational purposes.
Standard Precautions apply to all patients, regardless of diagnosis. Standard Precautions expands the coverage of Universal Precautions by recognizing that any body fluid may contain contagious microorganisms. Standard Precautions are implemented by donning gloves when anticipating contact with blood, all body fluids, secretions, and excretions except sweat, regardless of whether they contain visible blood, non-intact skin and mucous membranes.
Standard Precautions requires hand washing promptly after touching blood, body fluids, secretions, excretions, and contaminated items, whether or not gloves are worn. Hands must be washed immediately after gloves are removed, between patient contacts, and when otherwise indicated to avoid transfer of microorganisms to other patients, staff, or environments. Hands must be washed between tasks and procedures on the same patient to prevent cross-contamination of different body sites. An antimicrobial soap is used for routine hand washing.
Patient-care equipment that has been soiled with blood, body fluids, secretions, and excretions must be handled in a manner that prevents skin and mucous membrane exposure, contamination of clothing, and transfer of microorganisms to other patients and environments.
Reusable equipment in contact with non-intact skin, blood, body fluids or mucous membranes must be cleaned with a hospital approved disinfectant before it is used for the care of another patient.
Sterilization Policies. Biosafety staff provide autoclave technical advice to central sterile supply and clinical laboratories. Issues include autoclaving times for decontamination of laboratory waste, odor control (not recommended), and selection of sterilization process chemical and biological indicators. A rapid biological indicator was selected for central sterile supply because results could be obtained within a few minutes, thereby permitting the rapid release of sterile supplies for use in the hospital.
Chemical indicators show that proper temperature was reached during a sterilization cycle. They do not provide proof that six logs (106) of bacterial spores were killed (sterilization).
Sterilization processes with commercially available indicators with performance standards are; ethylene oxide, steam autoclave, gamma radiation, electron-beam radiation, formaldehyde/moist heat, and dry heat.
Biological indicators, such as Bacillus stearothermophilus spores indicate proper conditions for sterilization were present. This is the industry gold standard for steam sterilizer efficacy testing. There are rapid (less than thirty seconds) biological indicators based on a colorimetric test to confirm that a heat stable enzyme was inactivated during a sterilization process.
When the numbers of microorganisms on environmental surfaces or equipment (bioburden) is unknown, the most appropriate method to validate sterilization is the overkill method. Validation by the overkill method involves demonstrating that 106 spores will be killed in a half cycle. Thus a full cycle would result in a 12 log (1012) reduction of spores and produce a sterility assurance level (SAL) of 10-6, or a one-in-a-million statistical chance of a non-sterile sample.
Monitoring should be performed weekly, preferably daily in hospital OR’s, and after installation or any repair. The CDC recommends that every load containing implantable medical devices be monitored. The Association for the Advancement of Medical Instrumentation (AAMI) recommends monitoring at least weekly, but preferably daily. The Association of Operating Room Nurses (AORN) and the American Society for Healthcare Central Service Professionals (ASHCSP) suggest daily monitoring. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) recommends that the facilities determine monitoring frequency.
Autoclaving is not recommended for dense materials. There are specific guidelines to evaluate sterilizer efficacy using AAMI 16-towel test packs, AAMI Bowie-Dick test packs, and AAMI challenge test packs.
Tuberculosis Control Program. The biosafety division chairs the tuberculosis control committee and writes the tuberculosis control policy in collaboration with employee health, infection control and nursing. The employee tuberculin testing policy is currently being revised to reflect the low numbers of infectious TB patients in the Baltimore area. The tuberculin skin test is given to all new employees and annually thereafter to direct patient care healthcare workers with potential exposure to TB patients as determined by their supervisor.
Early TB control training materials consisted of a multiple page brochure that covered most program components of the policy. Currently, the biosafety officer uses a three panel brochure to present physician training and policy updates during monthly risk management seminars for physicians.
Nursing staff training is accomplished by self-study manuals placed at all nursing stations. Nurses read these manuals and take a quiz that is returned to nursing administration that forwards the results to the Office of Health, Safety and Environment. Nursing staff that work in TB patient areas are trained by the biosafety staff on how to operate, clean and store PAPR equipment.
Support associates receive tuberculosis training by biosafety staff at least once a year. Training sessions involve question and answer sessions directed toward topics that are important to support associate duties. Topics include how TB is transmitted, the signs and symptoms of TB disease, procedures for use of PAPR equipment, and use of tuberculin skin testing. Support associates also complete a short version respiratory surveillance form
Vacuum Delivery Systems. Many hospitals use vacuum delivery systems to move materials from one area to another. Biosafety issues arise when these systems are used to deliver medications to nursing units and specimens to laboratories. If a medication or patient specimen breaks during transit, there must be a written protocol to disinfect and decontaminate the system so that these materials do not spread within the vacuum tube delivery system or contaminate the baskets at the end of each delivery tube.
A written decontamination protocol was developed to ensure that the vacuum pumps, delivery tubes, shuttles, and delivery baskets would be properly decontaminated and cleaned when there is contamination by powder or liquids in the vacuum system.
Personal Protective Equipment.
Eye Protection. Glasses with side shields are the minimum acceptable eye protection in posted areas. They are used when there is a splash hazard with small quantities of chemicals or biological fluids, such as opening a bottle or tube, and when protection is needed from impact with small particles. Goggles are worn when working with liquids that are caustic or with larger volumes of hazardous chemicals or biological fluids. Face shields are worn when working with large volumes of hazardous chemicals and biological fluids, when there is a need to protect eyes and face, and when removing closed containers from liquid nitrogen or other cryogenic liquids. Special eye protection such as an ultraviolet (UV) absorbing full face shield is worn when working with transilluminators. Wavelength specific protective eyewear is worn when working with Class 3b and Class 4 medical lasers.
Face Protection. A mask and eye protection, a face shield, or a table mounted splash shield are used to protect mucous membranes of the eyes, nose, and mouth during all procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions or excretions. This equipment is used when removing stoppers from blood collection tubes and for all other procedures that have been associated with splashes to the face.
Gloves. Clean, non-sterile vinyl gloves are worn when touching blood, body fluids, secretions, excretions, and contaminated items and when performing venipuncture and other vascular procedures. Clean gloves must be put on just before touching mucous membranes and non-intact skin. Gloves must be changed between tasks and procedures on the same patient, and after contact with material that may contain a high concentration of microorganisms. Gloves must be removed promptly after use, before touching non-contaminated items and surfaces, and before going to another patient. Gloves are changed between tasks and between procedures on the same patient if contact occurs with contaminated material. Hands are washed promptly after removing gloves and before leaving a patient care area.
Gowns. A rear-fastening cotton gown with knitted cuffs is recommended when working at biological safety cabinets. Gowns must be worn to protect skin and to prevent soiling of clothing during all procedures or patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions. Selection of gowns and gown materials should be suitable for the activity and amount of body fluid likely to be encountered. Soiled gowns must be removed promptly and hands are washed to avoid transfer of microorganisms to other patients and environments.
Head and Foot Covers. Head and foot covers are worn to prevent soiling of clothing during all procedures that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions. They are also worn to reduce contamination of operating room floors (foot covers) and the sterile field in (head cover) during surgical or clean room procedures.
Respirators. NIOSH approved respirators are generally restricted to N95 negative pressure respirators or portable powered air purifying personal HEPA respirators (PAPRs) when entering airborne isolation rooms. N95 respirators are only used when PAPRs are not available at Johns Hopkins Hospital. These respirators are also worn when delivering gene therapy or drug aerosols to patients when the aerosol is not contained by engineering controls such as a reverse flow clean air bench.
Uniforms. Uniforms are generally worn by healthcare personnel to protect their personal clothes or skin. Uniforms also provide a method to identify individuals with special duties.
Biosafety Interactions with Administrative Units. The amount of biosafety staff time involved with Johns Hopkins Hospital administrative units or departments varies with the knowledge and experience of the biosafety staff. These interactions are also affected by the hospital safety reporting structure to the hospital’s senior administration. Safety programs that report to the medical affairs division, as is the case at Johns Hopkins Hospital, may have responsibilities that are not the same as safety programs that report to risk management, facilities, or human resources. Interactions between biosafety staff and hospital units at Johns Hopkins Hospital are briefly described below.
Clinical Engineering. Minimal interaction is needed beyond bloodborne pathogens training and development of procedures to tag medical equipment contaminated with blood before it is repaired.
Clinical Laboratories. There is moderate interaction that is concerned with identification of environmental microorganisms and developing proper waste management policies, including autoclaving of cultures and modified medical waste containers to accommodate the large volumes of glass and plastic discarded by the laboratory.
The biosafety division worked for several years with the clinical mycology section to identify environmental fungi. This laboratory has become adept at speciating environmental fungi, a specialty that is not available in most clinical laboratories.
Facilities. Interactions are frequent because of ongoing design and construction projects, biosafety staff certification of HEPA filter equipment, as well as assisting with development of vendor specifications for laboratory equipment.
Housekeeping. Minimal interaction is required other than periodic bloodborne pathogen training because the housekeeping department is trained to handle most medical waste issues and has a detailed procedure manual. Housekeeping maintains hospital medical waste manifests for the six tons of hospital medical waste that is trucked to a local medical waste incinerator every day.
Human Resources. Very little interaction is needed except for assistance with enforcement and documentation of employee safety policies during employee annual performance reviews and scheduling training time for new employees.
Infection Control. Frequent interaction is needed, including representation on the Infection Control Committee due to overlap between patient and employee biosafety issues described above.
Legal Affairs. Moderate interaction includes monthly committee meetings and biosafety training at physician risk management seminars.
Nursing. Minimal interaction is needed because most biosafety issues are handled by self study booklets. Biosafety, infection control, and medical divisions review the information presented in the self study program. Biosafety programs do benefit from increased biosafety staff participation in nursing staff training and review of work practices.
Occupational Health Services. Frequent interaction is needed because of the bloodborne pathogen and TB control program training information and medical surveillance.
Occupational Injury Management. Heavy interaction is needed because of the bloodborne pathogen exposure hotline activities that involve investigation of exposure incidents by the biosafety staff.
Materials Management (Purchasing). Minimal interaction is needed except to collaborate on selection of biosafety-related equipment and supplies to be stocked by central supply.
Biosafety Related Hospital Committees. Biosafety staff representation on hospital committees depends on each hospital’s reporting structure. Interactions with Johns Hopkins Hospital committees are briefly outlined below.
Hospital Safety Committee. Monthly biosafety staff attendance is required
Infection Control Committee. Monthly biosafety staff attendance is required.
Protective Devices Committee. Attend when biosafety-related engineering controls, such as gloves and sharps containers are reviewed.
Institutional Biological Safety Committee (IBC). This committee meets when needed to review human gene therapy projects, revisions to Biosafety Level 3 (BL-3) laboratory standard operating manuals and other research involving human materials, goats and sheep, non-human primates and select agents. This committee reviews all human subject protocols that have a biosafety component and may take a direct role in training nursing staff caring for gene therapy patients, especially those procedures involving administration of gene vectors by the respiratory route. The hospital has inpatient clinical research units for patients enrolled in these studies.
At large medical centers, such as Johns Hopkins Hospital, IBC activities require at least one full time biosafety staff member to handle research registrations involving patient material, annually updating registrations and managing a database of over one thousand nine hundred research projects.
Institutional Review Board. Attendance is required when human subjects genetic therapy projects are discussed. The biosafety staff review human subjects protocols that may involve bloodborne pathogens, microorganisms, biological agents or materials and select agents.
Summary. Biosafety is one of the most rapidly expanding fields in the safety field. Control of the transmission of microorganisms to and from hospital employees involves proper use of administrative controls, personal protective equipment, engineering controls, and medical surveillance. The time has come for most hospitals, especially large tertiary care teaching hospitals, to employ staff members with a microbiology background and knowledge of biosafety areas described in this chapter.
Attending hospital committees or workgroups that deal with employee exposure to microorganisms is a useful way to become familiar with hospital biosafety issues. Visiting the web sites listed in this chapter and attending national meetings hosted by biosafety professional associations such as the American Biological Safety Association will further enhance these experiences.
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