How is it diagnosed

As early symptoms are non-specific blood and stool examination (culture) is important diagnostic tool.
Blood culture - culture becomes positive in first week of disease.
Stool examination - stool culture becomes positive in second and third week of illness.
Serological test - Widal test- in second week of illness sufficient antibodies are formed that can be detected. Significant rise in titre is important in blood samples taken three to four days apart.