A prospective study of inhouse developed SEVA TB ELISA using cocktail of antigens and their immunoglobulins in the diagnosis of tuberculosis suspected patients in a tertiary care hospital located in rural area

An inhouse developed SEVA TB ELISA using cocktail of Mycobacterium ExcretorySecretory antigens (ES-31, ES-43 & EST-6) for antibody detection and their affinity purified antibodies for antigen detection was prospectively evaluated during January-August 2008 in TB suspected patients in tertiary hospital located in rural area. Antibody or antigen positivity is considered as ELISA positive. 238 suspected cases of pulmonary and extrapulmonary tuberculosis were screened. ELISA test showed 100% correlation (12 patients) with AFB positivity. ELISA test also showed 100% correlation (42 patients) with antitubercular therapy (ATT) treated cases. 110 out of 238 cases showed negative ELISA test and these cases were also not recommended ATT. 86 out of 238 cases were neither AFB positive nor ATT treated, but these cases were ELISA positive. These cases may possibly have dormant infection and need further follow up for showing disease, if any, in due course of time and its usefulness for confirmation of clinical suspicion. This study has shown usefulness of SEVA TB ELISA in diagnosis of suspected patients of Pulmonary and Extrapulmonary tuberculosis