The early bactericidal activities (EBAs) of 300 mg isoniazid, 18.5 mg isoniazid, 600 mg rifampicin and 800 mg ofloxacin given daily to 262 patients with newly diagnosed pulmonary tuberculosis in Cape Town, Nairobi, Madras and Hong Kong were measured by counting cfu and total acid-fast bacilli in sputum collections taken pre-treatment (S1), at 2 days (S3) and at 5 days (S6). In Cape Town, Nairobi and Madras, the cfu findings suggested that isoniazid produced a massive kill, perhaps of actively growing organisms, during the first 2 days (mean S1-S3 EBAs of 0.636-1.006) but was almost inactive thereafter (mean S3-S6 EBAs of 0.000-0.081), whereas rifampicin maintained moderate activity against slowly growing organisms throughout the 5 days (mean S3-S6 EBAs of 0.242-0.305). This finding suggests that EBAs measured during the 2-5 day interval might be able to assess the sterilizing activity of drugs. Ofloxacin had moderately high mean S1-S3 EBAs of 0.130-0.391. However, in Hong Kong rifampicin appeared to be the most bactericidal drug from the start, possibly because patients had more chronic disease. A method of adjusting the cfu EBAs using total counts was devised which decreased the variability between patients within a treatment group without altering the mean cfu EBA. This resulted in a large gain in precision in Hong Kong, suggesting that their estimates were greatly affected by type II variation, due to dilution of pus by saliva and bronchial secretions, whereas small or no gains were obtained in the other three centres, suggesting that the main cause of variability was type I, due to other factors.

Summaryobjective To define the bacteriological and histological correlates of the three predominant clinical forms of cutaneous tuberculosis and to evaluate the efficacy of a 9-month daily regimen containing rifampicin and isoniazid.methods In the dermatological clinics of two major teaching hospitals in Chennai, 213 patients with suspected clinical manifestations of cutaneous tuberculosis underwent examination and a skin biopsy for bacteriological and histological tests. They were treated with a daily regimen of rifampicin and isoniazid for 9 months and follow-up for 3 years.results Bacteriological and/or histological confirmation of tuberculosis was obtained in 88% of the cases. Lupus vulgaris lesions were seen mainly in the extremities and verrucosa cutis occurred predominantly on the sole and foot, while the cervical and axillary regions were the commonest sites for scrofuloderma. Ninety-two per cent of the patients showed resolution of the lesions within the first 6 months of chemotherapy; 1% failed to respond to this regimen. There was no relapse in any of the cases during the follow-up period of 3 years.conclusions Clinical findings were adequate to identify major forms of cutaneous tuberculosis as evidenced by bacteriological and histopathological examination. A daily regimen of rifampicin and isoniazid for 9 months was effective in treating cutaneous tuberculosis.

Effective antituberculous chemotherapy will lead to a substantial reduction of fibrosis and the consequent disability that can arise in patients with tuberculosis.

Sirs,We would like to thank Dr Ramesh et al. (2007) for raising very important issues about our paper on cutaneous tuberculosis (Jawahar et al. 2005). We offer the following clarification for the points raised.Of the 182 patients who underwent a Mantoux test, four had a reading of 5 mm or less (three had 5 mm; one had 3 mm). These patients were not included in the table. Among patients who showed a reaction of >15 mm in LV (row 3, column 2 of Table 1), the percentage positivity should be 73 instead of 94. We regret this transcriptional error.Of the 20 patients with NTM cultures, 9 had LV, 10 VC and 1 SD. One patient with SD and one patient with LV could not be Mantoux-tested. Of the remaining 18 patients, 13 had a reaction >10 mm. Clinically, these patients did not differ in any way from those who were positive for Mycobacterium tuberculosis. Histological evidence of tuberculosis was seen in all except two patients with LV. Further, clinical resolution began during the first month of treatment; the symptoms of 19 patients had completely resolved by month 5; those of the remaining patient by month 8. Thus, the response of NTM patients was similar to that of patients with M. tuberculosis infection. We did not test the NTM isolates for drug sensitivity.As we mention in the paper, all patients who were resistant to one drug responded clinically. In one of the two patients who had MDR, the lesion resolved completely; at the end of chemotherapy a repeat biopsy did not show histopathological or bacteriological evidence of tuberculosis. The other patient was highly irregular during treatment and died of myocardial infarction later. We used HR in the study based on our own experience with TB lymphadenitis and spinal tuberculosis, where patients treated with HR showed good response. These patients were evaluated at monthly intervals so that treatment could be modified if necessary. Currently, with increasing evidence of drug resistance, the recommended regimen of RHZ followed by RH can be advocated for treating paucibacillary extra-pulmonary forms of TB including CT.Clinical diagnosis could not be confirmed by either histopathology or bacteriology in 13 patients. Clinical evidence and a tuberculin reaction of >15 mm were observed in eight of nine cases where the test was carried out. All 13 patients showed regression of the lesion after 1 month of treatment; complete resolution was seen in nine within 3 months and within 6 months in the remaining four. Thus, lesions resolved in all patients whose clinical diagnosis could not be confirmed by laboratory tests. We are not in a position to react to the comments on a therapeutic trial as almost all our patients had evidence of direct or indirect proof for diagnosis.

Childhood spondylodiscitis is an extremely rare entity and accounts for 2-4% in neonates. Respiratory and other site infections are identified as sources of hematogenous spread. A 5-week-old male child was brought to the emergency department with respiratory distress and convulsions. On the evaluation, he had bilateral bronchopneumonia with septicemia and kyphosis. Computed tomography scan demonstrated spondylodiscitis with destruction of T 5-T 6 vertebrae with abscess of right lower lobe of the lung. Subsequently, thoracotomy was done, and a biopsy sent from apical and posterior segments of the lower lobe of the right lung revealed bronchopneumonia, abscess with entrapped dead bony spicules and collapse. Early diagnosis and treatment of respiratory infections are critical as delay may result in vertebral destruction as seen in this case and could lead to potentially life-threatening complications.