Q: I am a 32 years old man diagnosed with abdominal tuberculosis (TB) based on analysis of fluid aspirated from my abdomen. Ten months back I started Omnacortil 60mg which was tapered off over 6 weeks. I also took Rimactazid Plus, Pyrazinmide for first 2 months, Ethambutol and multi-vitamin syrup. Though there was a marked improvement in my condition, I was still having low grade fever (around 100 degrees) every evening, even after 2 months of treatment. I consulted a gastroenterologist who advised ultrasonography (USG) and CT scan , which showed localised fluid collection in pelvis. It also revealed fatty infiltration of liver, small residual fluid collection in right iliac fossa and small fluid collection in right hypochondrium. Also, PCR for M. tuberculosis did not detect Mycobacterium tuberculosis DNA and the TB culture report showed ‘no growth of acid fast bacilli’. Medicines Neksium, Benadon and Motinorm were added. Ascitic fluid examination after 4 months of treatment showed ADA level of 35 U/L, Protein 5.9 g/dL, Albumin 3.2 g/dL, Lymphocytes 98%. Latest chest X-ray shows lobular opacity in right paratracheal region. I recently underwent laparoscopy and the findings were: thickened peritoneum, dense omental adhesions present to the abdominal wall, no ascites,and non-visualisation of liver due to adhesions. Biopsy showed granulomatous peritonitis of probable tuberculous aetiology. The improvement in my condition has been very slow and even after r 5 months of regular treatment I still have low grade fever every evening (99.2-99.5 degrees F) along with weakness. I have gained some weight over last 2 months and am just 3-4 kg less than my normal weight. The doctor says that I am still having TB and would get well in due course of time and asked me to continue with the same treatment. Am I taking right treatment? What do the USG / CT /X-ray and Laparoscopy findings indicate? Why does PCR and TB culture show negative reports as far as TB is concerned? Do I need to go for some other tests to get a final confirmation?

A:The diagnosis of tuberculosis (TB), like any other clinical condition, is reliant on a number of clinical, epidemiological, and investigation related factors. A few laboratory tests cannot be used in isolation to exclude or diagnose a disease. TB is a common clinical problem in India, and the signs and symptoms described are consistent with TB, although other possibilities exist. The decision to treat this as a case of TB has been based on overall clinical judgement (based on the clinical features, radiological, histopathology and other lab reports such as ascitic fluid analysis) - and as mentioned previously that decision is consistent with the clinical information provided. The fact that PCR and bacterial culture for TB is negative does not rule out TB. The results of these tests could be affected by many factors such as sensitivity, quality assurance program of the lab, adequacy of the sample, method used for culture and PCR, whether sample was taken before or after starting anti-TB therapy, etc. Adenosine deaminase testing (ADA) is a sensitive test to diagnose TB related aetiologies with a restricted specificity. Fever, not coming down totally may be due to many reasons, and sometimes depending on the site of disease, total cure of the disease and eradication of the organisms may take some time. The fact that you seem to be responding to treatment (as manifested by weight gain, decrease in temperature, and improvement in appetite) although slowly is encouraging and seems to indicate treatment is progressing in the right direction.