Description
Enteric fever occurs when pathogenic microorganisms like S. typhi, S. paratyphi A and S. paratyphi B infect the human body. During the course of
disease, the body responds to this antigenic stimulus by producing antibodies whose titre rises slowly in early stages, to a maxima and then slowly
falls till it is undetectable. Antibodies to Salmonella organisms may be detected in the patient serum from the second week after onset of infection.
Information regarding the titres and whether or not they are rising or falling can be obtained by performing serological tests using WIDAL
antigen suspensions. Usually tube titres of 1:80 and above are taken as diagnostically significant, however for endemic areas higher cut-offs may need to be established.
