Abstract:
The diagnosis of disease, during the course of studies on epidemiology or more
commonly as a prelude to control, differs in many ways from the identleaticr and
taxonomy of the causal microorganisms or other pathogenic agents. A plait is ;aid
to be diseased when its normal functions are disturbed and harmed (Ho]i Jay, 1939).
This is a complex condition and provides many more opportunities for t:',etection nd
diagnosis than the pathogen alone.