I comply the more readily with the suggestion of the Chairman of this Section that my remarks in opening this discussion on the "Serum Diagnosis of Typhoid Fever," shall relate to the general principles of the method, inasmuch as the results obtained by this method at the Johns Hopkins Hospital will be presented in the course of this discussion by Dr. Block, and others will relate the results of their personal experience.
Before the introduction of the Widal method of diagnosis the discovery and subsequent studies of the typhoid bacillus had been comparatively barren of results available to the general practitioner of medicine. In this respect the typhoid bacillus afforded a marked contrast to many other pathogenic microörganisms, notably the tubercle bacillus, the diphtheria bacillus and the malarial parasite.
For various reasons improved methods of diagnosis of typhoid fever are most welcome to the practitioner. Inasmuch as the prevalence of
WELCH WH. PRINCIPLES UNDERLYING THE SERUM DIAGNOSIS OF TYPHOID FEVER AND THE METHODS OF ITS APPLICATION.. JAMA. 1897;XXIX(7):301–309. doi:10.1001/jama.1897.02440330001001