Study on Salmonella Typhi-Isolation, characterization and immunological studies

Abstract

Typhoid fever is one of the most common febrile illnesses and its real impact is difficult to estimate because the clinical picture is confused with other febrile infections. Various diagnostic techniques are used for clinical diagnosis of typhoid patients. Unfortunately no technique so far us'P for can be considered as gold standard as a diagnostic tool for typhoid fever. Widal test is widely used in the developing countries for the diagnosis of the typhoid fever; however, Widal test takes a longer time for diagnosis . having high proportion of false positive results which would complicate the treatment. Blood culture technique is limited due to the indiscriminate use of antibiotics and its utility is restricted due to low numbers of bacteria in blood. Antibodies in lymphocyte supernatant (ALS) assay has recently been developed and standardized for the diagnosis aj typhoid fever which is highly sensitive for detection of Salmonella Typhi infection at early stage. Comparison of ALS assay with blood culture and Widal test has been carried out and the method is sensitive and specific. AL$ able to confirm typhoid infection in 52% patients, whereas, blood culture test confirmed 13% and Widal test confirmed 44% patients to be positive on Salmonella Typhi. Using ALS assay typhoid fever was diagnosed and confirmed within 48 hrs of fever. ALS assay can be used for rapid diagnosis of typhoid fever.