infectious hazards described in this chapter are considered acutely or chronically pathogenic in nonhuman primates, and well-structured programs of veterinary care should help to identify and eliminate many of these agents from research colonies. Others typically exist for long periods as asymptomatic infections and require special efforts in disease surveillance, often with limited therapeutic options for their complete eradication. Whether these infections can be sustained in research-colony settings depends on the species of nonhuman primate, the biology of the agent, systems of husbandry and veterinary care, and the presence of competent invertebrate vectors. Likewise, the potential for occupational exposure to the agents varies with the collection of species, the type of research use, systems of husbandry and veterinary care, and contact with other vertebrate and invertebrate species at each institution. Other chapters of this book contrast the exposure rates of persons who work with nonhuman primates in a risk-based context and provide a framework for developing and monitoring programs of safety appropriate to these concerns in the modern era.