Precipitable Typhoid Somatic Antigen in the Serum of Typhoid Fever Patients

Abstract

Report that the presence of antigen of Eberthella typhosa has been demonstrated in the serum of typhoid fever patients early in the disease. The test is most strongly positive when the somatic "0" agglutinin titer of the patient''s serum is low; it becomes progressively less positive, and finally negative, as the titer approaches 1:640. The precipitin test as described, therefore, is a useful rapid presumptive test for the diagnosis of typhoid fever in inoculated or non-inoculated subjects during the first 7 to 10 days of the disease. A positive test clearly indicates typhoid fever; a negative test does not exclude typhoid or the related enteric fevers.