characteristic of inheres in role primary infection role Alexander Diehl A role borne by an infectious disorder in virtue of the fact that (1) the host has at least two distinct infectious disorders, where neither arose from the other through metastasis, (2) at the time the infectious disorder was established in the host, the host had no infectious disorder, and (3) the infectious disorder increases the host's susceptibility to infectious disorders. Lindsay Cowell Albert Goldfain The role is realized in a process by which the infectious disorder is established in the host. secondary infection role infectious disorder host role source of infection role