Is a positive Elisa test diagnostic of tuberculosis?
Q: My 6-year-old son's was a premature baby. His Elisa test is positive (1.26 IGM). He has two knots at his neck due to which the doctor advised this test. Is tuberculosis curable? How much time will it take? Doctor says it takes 6-9 month's regular treatment. Is there any treatment of lesser period? Is there a medicine to cure this? What care has to be taken during this treatment? What should be the diet of the patient?
A:Definitive diagnosis of TB depends upon isolation of the organism from secretions or biopsy specimens. Despite innovations in rapid diagnosis, many of the classic diagnostic tools remain useful and continue to be involved in the evaluation of patients with TB. No available serodiagnostic test for TB (including ELISA) has adequate sensitivity and specificity for routine use in diagnosing TB in children. The diagnosis should be confirmed before starting any treatment. Specimen should be obtained from the lymph nodes. Culture of mycobacterium is the definitive method to detect bacilli. It is also more sensitive than examination of the smear. Another advantage of culture is that it allows specific species identification and testing for recognition of drug susceptibility patterns. Nucleic acid hybridization using molecular probes has become widely accepted and their sensitivity and specificity approach 100% when at least 100,000 organisms are present. Polymerase chain reaction (PCR) and other amplification tests allows the direct identification of M tuberculosis in clinical specimens, unlike the nucleic acid probes, which require substantial time for bacterial accumulation in broth culture. Current recommendations for the treatment of pulmonary TB include a 6-month course of INH and rifampin, supplemented during the first 2 months with pyrazinamide. Ethambutol (or streptomycin in children too young to be monitored for visual acuity) may need to be included in the initial regimen until the results of drug susceptibility studies are available. Another treatment option is a 2-month regimen of INH, rifampin, and pyrazinamide daily, followed by 4 months of INH and rifampin twice a week. Effective treatment of hilar adenopathy when the organisms are fully susceptible is a 9-month regimen of INH and rifampin daily or a 1-month regimen of INH and rifampin once a day followed by 8 months of INH and rifampin twice a week.