A review of common infectious disease agents of laboratory mice and rats: potential influence on Pneumocystis carinii.

The influence of viruses and bacteria on Pneumocystis carinii pneumonia (PCP) is suspected but not known for certain. A number of adventitious viruses and bacteria are common among commercially available and institutionally raised rodents, which may impact upon, or interfere with, the induction of PCP in rodents in several ways. Based upon the biological behavior and prevalence of certain rodent agents, the potential for such impact is great. Infectious agents can directly interfere with research by inducing severe disease in the immunocompromised host. They may also influence the course of P. carinii infection or disease via direct effects upon the respiratory tract or via indirect effects on lymphoreticular cells or other organ systems. Examples of likely agents and their potential effects are discussed.