Animal Welfare Regulations state that institutions should appoint a committee (an institutional animal care and use committee, or IACUC) that is responsible for evaluating their animal care and use programs. Investigators have the obligation to assure review committees that animals will be treated humanely. Research on infectious diseases, effects of atypical rearing conditions, and pathological behavior pose special problems both for those establishing and maintaining enrichment programs and for those inspecting and reviewing such programs. Other circumstances in which experimental manipulations lead to changes in an animal's behavior—such as those related to surgery, drug or chemical treatment, or restriction of movement—also require special consideration to evaluate the animals appropriately and provide as well as possible for their psychological well-being. Investigators and IACUCs should periodically re-evaluate protocols in which animals experience special research conditions. They should be aware that knowledge about aspects of research procedures that cause distress and about methods to mitigate unwanted and unnecessary negative effects is changing continuously.
Studies that use nonhuman primates for infectious-disease research of necessity invoke several precautionary measures, for example, specialized animal holding units for animal and personnel safety (CDC/NIH 1993; NRC 1997a), use of protective clothing, and restricted access to animal areas. A frequent result of such safety measures is an environment that lacks sensory input or challenge to the animal. This is a particular concern when animals are housed in biocontainment units.
It is the responsibility of the investigator, veterinarian, and IACUC to determine the type of biocontainment necessary for a particular research study. Topics that should form the basis of the assessment include the goals of biocontainment, the mode of transmission and biosafety level of the agent, and the object of protection (the personnel, subject animals, and other animals in the facility). For example, research animals might be maintained in biocontainment units to protect personnel from a hazardous agent, to protect the subject animals from adventitious agents in the environment that could interfere with the research, or to protect other animals in the facility from the agent by isolating the infected subject animals. The means of achieving biocontainment should also be carefully evaluated, especially considering the psychological well-being of the primates. For some hazardous agents, protective clothing can be a sufficient biosafety barrier; in other cases, both cage and room barriers with specialized ventilation equipment are necessary.
Regardless of the degree of biocontainment, it is the consensus of this committee that biosafety concerns alone do not justify sensory or behavioral isolation