Koch's Postulates, Disease Definitions, and Pathogen Types

Suspected germ present in all cases

Germ must be isolated and grown in pure culture

Germ must cause disease when introduced into a healthy host

Germ must be re-isolated from the diseased experimental host

A) Pathogens can be found in healthy host

B) Some pathogens can't be cultured in lab

C) All diseases are caused by a single pathogen

D) Disease can be caused by more than 1 pathogen

invasion

elimination

protection

vaccination

Symptoms are subjective characteristics of disease felt by the patient, while signs are objective manifestations of disease that can be observed or measured by others.

Symptoms are always visible, while signs are always hidden.

Symptoms are measured by doctors, while signs are only described by patients.

Symptoms and signs are both subjective experiences of the patient.

Incubation

Convalescence

Prodromal

Acute

True

False

A primary pathogen causes disease in the host regardless of host resident microbiota/immune system.

A primary pathogen only infects immunocompromised hosts.

A primary pathogen is a harmless microorganism.

A primary pathogen only exists in laboratory conditions.

do not

always

frequently

inevitably

consistently

rarely

temporarily

occasionally

temporary

permanent

harmful

beneficial