Qualitative or Quantitative Methods in the Serological Diagnosis of Enteric Infections?

Abstract

1. “Normal” agglutinins for B. typhosus and B. paratyphosus B appear to be conclusively of the O type.2. Such agglutinins appear to be of consistently low titre and are absent in many sera.3. Normal agglutinins for B. paratyphosus A have not been encountered.4. O agglutinins are readily produced by inoculation of a T.A.B. vaccine, and may rise to as high titres as those encountered during an enteric infection.5. It is impossible to fix any limit for residual O agglutinins in inoculated persons.6. The value of examining for O agglutinins in enteric cases is confirmed.7. Some fallacies of a purely qualitative method are pointed out, and a plea is made for the inclusion of the principles of qualitative receptor analysis in a quantitative Widal.