how do we interpret widal test to diagnose typhoid fever?

Answer 1

This test is now outdated. there are better tests. However, generally, a titre of 1: 60 or more is supposed to be diagnostic for endemic areas, otherwise, 1: 80 or more. Rising titre is more significant, i.e. when you repeat the test after a few days, the titre is more. Widal is positive late in the first week of illness onwards. Initially, O antibodies rise and later, F antibodies are more. F antibodies indicate previous infection or vaccination.

Answer 2

Rising titre is diagnosic. Stool cultures also.