Table 1.
Categories of potential pathogens resulting from xenotransplantation (examples and availability of validated microbiological assays)
| Common Human Pathogens of Allotransplant Recipients (EBV, CMV, herpes simplex virus, varicella zoster virus, Apergillus species, Listeria monocytogenes, mycobacterial species, Pneumocystis jirovecii) |
| Specific microbiological assays are generally available |
| Traditional Zoonoses: well-characterized clinical syndromes of humans (Toxoplasma gondii) |
| Specific microbiological assays are generally available |
| Species-specific agents: organisms generally thought to be incapable of causing infection outside the xenograft (e.g., porcine CMV) |
| Some specific microbiological assays are available; few standardized assays available for use in humans |
| Potential pathogens: Organisms of broad “host range” which may spread beyond the xenograft (adenovirus) |
| Some specific microbiological assays are available for use in humans, may not be standardized for porcine strains |
| Unknown pathogens: Organisms not known to be human pathogens, not known to be present in the source animals, or for which clinical syndromes and microbiologic assays are poorly described or unknown |
| New pathogenicity within the new host, while not known to be present or pathogenic (e.g., protozoa or retroviruses) |
| Viral recombinants resulting from intentional genetic modification of donor diseases resulting from multiple simultaneous infections |