Table 2.
Proposed revisions to terminology of microbial pathogenesis in the context of the damage framework
| Term | Revised definition |
|---|---|
| Carrier state | Synonymous with colonization |
| Chronicity | Synonymous with persistence |
| Colonization | A state of infection that results in a continuum of damage from none to great, with the latter leading to the induction of host responses that could eliminate or retain the microbe, or progress to chronicity or disease; for organisms that induce no damage during infection this state is indistinguishable from commensalism |
| Commensal | Microbe that induces either no damage or clinically inapparent damage after primary infection; a state that is thought to be established early in life |
| Commensalism | A state of infection that results in either no damage or clinically inapparent damage to the host, though it can elicit an immune response |
| Damage | The interruption of normal tissue structure and/or function of the host that applies at the cellular, tissue, and organ levels (necrosis, apoptosis, mutation, synaptic blockage, and malignant transformation are examples of damage at the cellular level; granulomatous inflammation, fibrosis, tumor are examples of damage at the tissue level; Ductal obstruction is an example of damage at the organ level); the presence of a microbe-specific immune response may be indicative of a heretofore unrecognized manifestation of damage |
| Elimination | Removal of the microbe from the boundaries of the host by either physical factors, interference by host flora, an immune response, or therapy |
| Infection | Acquisition of a microbe by host; most infections are followed by multiplication of the microbe in the host, but this is not universal because some helminth infections can involve a single organism that does not replicate in the host |
| Infectious disease | The clinical manifestation of damage that results from a host-microbe interaction |
| Latency | Synonymous with persistence, this term is often used to describe infections that are asymptomatic over long periods of time but can evolve into overt disease |
| Persistence | A state of infection in which the host response does not eliminate the microbe, resulting in continued damage over time; persistence may evolve into overt disease, depending on the balance of the host-microbe interaction (Fig. 1) |
| Pathogen | A microbe capable of causing host damage (as defined in reference 7) |
| Symbiosis and mutualism | A state of infection whereby both the host and the microbe benefit as a consequence of infection |
