1998 USAHA Committee on Foreign Animal Diseases

United States Animal Health Association

1998 Committee Reports


Report of the USAHA Committee
on Foreign Animal Diseases


Biocontainment


Report Contents

  • Biocontainment - Assessments for Animal Agriculture
  • Ticks
    • Assessing Risks to U.S. Livestock of Ticks and Tick-Borne Diseases
    • Tropical Bont Tick in the Caribbean: Changes in Funding and Administration

  • Emerging Diseases
    • APHIS Resources for Surveillance and Monitoring - An International Perspective
    • Hong Kong Influenza H5N1 Outbreak
    • An Occurrence of a Contagious Equine Metritis-"Like" Organism in Kentucky -- Investigation of a Disease Outbreak Among Nurse Mares
    • Classical Swine Fever in the Caribbean -- IICA and APHIS Initiatives
    • Safety and Efficacy of an E2 Subunit Classical Swine Fever (CSF)/Hog Cholera Marker Vaccine
    • Tracking Vesicular Stomatitis Virus Outbreaks Through DNA Sequencing
    • The Role of Insects in the Transmission of VSV to Livestock in the Western United States
    • Contact Transmission of VSV New Jersey in Swine

  • Animal Disease Status Worldwide in 1997 and 1998 (Through September)
  • Foreign Animal Disease and Pest Diagnosis and Research
    • Report of ARS and APHIS Activities at the Plum Island Animal Disease Center
    • Velogenic Viscerotropic Newcastle Disease (VVND) in California
    • Characterization of a new strain of foot-and-mouth disease virus from Taiwan
    • Novel Virulence and Host Range Genes of African Swine Fever Virus
    • The South American FMD Eradication Program: A Progress Report

  • Risk Assessment in International Trade
    • Estimating the Value of Animal Health: Surveillance and Monitoring Services by Simulating an Outbreak of FMD in California



Chairman: Mr. G. Gale Wagner, College Station, TX
Vice Chair: Dr. William W. Buisch, Aurora, CO


Biocontainment - Assessments for Animal Agriculture

Corrie Brown and Mike Kiley. Department of Veterinary Pathology (Brown), College of Veterinary Medicine, University of Georgia, Athens, GA; National Program Staff (Kiley), Agricultural Research Service, USDA, Beltsville, MD.

The supply of safe, affordable, and abundant food for the American consumer is continually threatened with disease outbreaks that could render animal-based protein unsafe or unavailable for consumption. Emergence of a new pathogen or incursion of a foreign disease agent are two mechanisms that could produce an agricultural crisis. In addition, the threat of biological terrorism looms larger every year as unethical individuals realize that economic ruin through disruption of the food supply could be an extremely effective weapon of terror and panic.

For each new agent or new outbreak, it is essential to develop adequate understanding of the agent and disease to devise means of diagnosis and control. This characterization is accomplished through both laboratory-based and epidemiological investigations. However, the ability to successfully study infectious animal diseases in the laboratory is predicated on a number of factors. These include pre-existing technical and scientific expertise on the disease or a closely related disease process, adequate funding, which in turn is directly related to prioritization of need, and lastly, availability of suitable facilities for studying the diseases. This review aims to address the latter issue, facilities.

In order to experimentally manipulate organisms and, in particular, to inoculate them into living hosts, certain safety criteria must be satisfied. A biosafety ranking system has been established for disease agents. The ranking criteria includes the nature of the agent as well as the types of experiments done with the agents. Levels are determined based on potential threat to the workers and the surrounding animal communities in a system referred to as "biosafety levels." There are four basic biosafety levels and the decision about placing agents in a category rests with the biosafety committee at the local institution. The local committee should have suitable expertise with the agent in question and knowledge of proper guidelines in order to make decisions on the appropriate biosafety-level assignment for agents and experiments. These biosafety levels are defined below and refer to a combination of workplace practices and primary and secondary containment barriers. The parameters described for each of the levels are designed to provide an environment that, when used properly, will protect personnel and the surroundings from hazards associated with the agents.

Biosafety Level 1 (BL1) is the least restrictive and is designed for those agents that are unlikely to cause disease in healthy workers or animals. They present both low individual and community risks. Agents at this level can be manipulated routinely on the bench top by a worker attired in a laboratory coat. A high school biology laboratory is an example of a BL1 laboratory.

Biosafety Level 2 (BL2) practices and facilities are designed for those pathogens that can cause human or animal disease but, under normal circumstances, are unlikely to be serious hazards to laboratory workers, the community, livestock, or the environment. There is moderate individual risk and the agents are already present in the community. Manipulations at this level may be done on the bench top but procedures that create aerosols should be performed in a laminar-flow biosafety cabinet. Most microbiological laboratories, including diagnostic laboratories, are rated at BL2.

Biosafety Level 3 (BL3) includes enhanced work practice and facility practices designed to allow study of pathogens that cause serious human disease or that can result in severe economic consequences to the livestock industry. The BL3 agent group includes indigenous or exotic agents with a potential for respiratory transmission that have significant morbidity and mortality and are not generally present in the community. Laboratory manipulation of these agents requires an anteroom, inward air flow, and appropriate laboratory clothing, either a scrub suit or wrap-around laboratory coat. Surfaces should be easy to decontaminate and work is conducted in laminar-flow biological safety cabinets. To work with BL3 agents in animals, the air must be filtered through HEPA filtration and the sewage should be decontaminated with heat.

Biosafety Level 3 "Agriculture" (BL3-Ag) is a specialized category of containment, introduced to define a biosafety level where the main goal is to protect the environment from agents that are a potential threat to plants or animals but not to humans. Additional features added to a basic BL3 laboratory to achieve BL3-Ag might include HEPA filtration of supply and/or exhaust air, personnel exit shower and decontamination of the liquid effluent.

Biosafety Level 4 (BL4) pathogens produce very serious human disease that is often untreatable, is exotic, and can spread readily among individuals. The agent causes high mortality and is not usually present in the community. Consequently this is a category involving high individual and community risk. Laboratory work with these agents requires the use of positive pressure-ventilation body suits or Class III biosafety cabinets.

Beyond the traditional four biosafety levels, U.S. Agriculture has an additional level, biosafety level 5 (BL5), designed for agents that by law are not allowed on the U.S. mainland. Both foot-and-mouth disease virus and rinderpest virus require that BL3-Ag facilities in which they are studied be separated from the mainland. There is only one facility in the U.S. that meets BL5 criteria -- the Plum Island Animal Disease Center.

Many emerging pathogens and virtually all foreign disease agents (excepting foot-and-mouth disease and rinderpest viruses) require BL3 for any experimentation and manipulation. Facilities capable of operating at BL3 or BL3-Ag for the study of animal diseases have historically existed within the federal infrastructure only. The USDA facilities are: the National Animal Disease Center, at Ames, Iowa; the Plum Island Animal Disease Center, on Long Island, N.Y.; the Arthropod-borne Animal Disease Research Laboratory, in Laramie, Wyo.; and the Southeast Poultry Research Laboratory, in Athens, Ga. These buildings are generally operated at full capacity with research directed and executed by USDA scientists. Within the last 10 years, there has been some impetus to build and develop BL3 laboratories outside of the federal government to try and meet the public's demands for increasing amounts of research on agents that fall into this biosafety level category. A list of those non-federal facilities having capabilities for BL3 work in animals is contained in Table 1.

Recently two new BL3 facilities dedicated completely to poultry diseases have been constructed. The University of Arkansas' Poultry Health Research Laboratory and the University of Delaware's Charles C. Allen Biotechnology Center, both state-of- the-art buildings, have come on line in the last four years. In addition, other BL3 facilities have designated areas available for poultry work. Development of increased capacity for studying disease in large animals under BL3 conditions has not moved as rapidly in the recent past. Michigan State University and the University of Nebraska both have facilities that could accommodate large animal studies; however, the latter is currently operating at BL2 only. Isolettes for holding single calves under BL3 conditions are available and in use at Texas A&M University. Cornell University has a facility that was recently upgraded to BL3 criteria with possibilities for studying large animal diseases. The University of Georgia has a building, scheduled to open in early 1999, with 16 BL3 animal rooms designed for a variety of animal species, including large animals. Five pairs of rooms have adjoining doors so that large suites can be created to accommodate vaccine challenge work in livestock.

The creation of these BL3 capabilities located at universities provides unique and unprecedented opportunities for partnership between the federal agenda and university-based researchers. With the rising availability of BL3 facilities, coupled with the ever-increasing threat of emerging and foreign diseases, the nation is in a better position to advance through scientific synergy between federal and non-federal scientists involved in agricultural research. As the regulatory concern about emerging and foreign pathogens increases, even in the face of federal downsizing, many of these issues can be addressed through alliances with academia by research conducted in non-federal BL3 facilities. The animal agriculture community needs to be more aware of these opportunities.
Table 1. Non-federal facilities having capabilities for BL3 work in animals.
Facility No, size of animal
rooms
HEPA
filtration
Sewage treatment Agents used Condition
University of Nebraska
Animal Research Facility
36 animal rooms, all capable of holding calves, all capable of BL3 IN and OUT steam sterilization PRRS, PR, BHV-1 built in 1979, currently operating at BL2
Michigan State University University Research Containment Facility 28 animal rooms, 8 are capable of BL3 IN and OUT (BL-3) steam sterilization M. bovis new facility, opened 1995
University of Georgia Animal Health Research Center 18 animal rooms, all multispecies, all capable of BL3 OUT steam sterilization
completed in fall of 1998
Texas A&M Veterinary Medical Park 9 isolettes, each capable of holding calves OUT steam sterilization M. bovis, M. tuberculosis, Salmonella built in 1988, excellent condition
Cornell University Small Animal Biosafety Facility 4,000 sq ft at BL3 OUT steam sterilization
new facility
Cornell University Large Animal Biocontainment Facility 19 rooms (10' x 12') OUT steam sterilization recombinant vaccines recent upgrade to older facility
University of Arkansas Poultry Health Research Laboratory 7 animal rooms, all for poultry IN and OUT steam sterilization Mycoplasma, IBD, IBV, CAA, Marek's opened in 1994
University of Delaware Charles C. Allen Biotechnology Center 8 animal rooms, all for poultry, facility is BL3 (Ag) IN and OUT steam sterilization various poultry pathogens, including IBV, ILT, IBD, AI (H5 and H7), ALJ, Marek's, CAA new facility, opened in 1997
University of Wisconsin 6 animal rooms OUT autoclaving and incineration chicken diseases built in 1981

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