This page was researched by Sumiko Mekaru . The concern with the greatest potential for disaster is that introducing tissues and organs from another species into a human may inadvertently introduce a pathogen which may mutate within the human host and thereby create a new human disease.
Discordant animals are less likely to have transmittable diseases than concordant animals.
1 Pigs, however, do harbor many diseases that are transmittable to humans. In fact, pigs are the mixing vessel for new strains of influenza. The major changes in the flu virus which cause epidemics occur when a new strain jumps from ducks to pigs and then from pigs to humans. Another human disease transmitted by pigs is the previously unrecognized paramyxovirus, a Hendra like virus, in Malaysia. 3 Many animals harbour diseases which can infect humans, and as is shown in the case of flu, these animals can play significant roles in the creation or mutation of these diseases.