Initial default among diagnosed sputum smear-positive pulmonary tuberculosis patients in Andhra Pradesh, India.

BACKGROUND: Under the Indian Revised National TB Control Programme (RNTCP), smear-positive pulmonary tuberculosis (PTB) patients not confirmed as starting treatment are reported as 'initial defaulters'. SETTING: Twenty districts of Andhra Pradesh State, India. OBJECTIVE: To evaluate reasons for treatment non-initiation in smear-positive PTB patients diagnosed and reported as initial defaulters by the NTP. DESIGN: A cross-sectional survey conducted of all reported initial defaulters during the period July-September 2006. RESULTS: Of 1304 reported initial defaulters, 619 (47.5%) had been placed on treatment, having been incorrectly reported due to poor documentation of patients referred for treatment in the same district or whose treatment initiation was delayed until the subsequent quarter. Of the 685 (4.5% of the total diagnosed) who were confirmed initial defaulters, 350 (51%) were untraceable, 152 (22%) had died before treatment initiation, 38 (5.5%) were treated privately, 93 (13.5%) had other reasons (e.g., refusal of treatment, chronic case, etc.) and no data were available for 52 (8%). CONCLUSIONS: Nearly 5% of smear-positive PTB patients diagnosed in the study period were confirmed as not having initiated treatment under the RNCTP. Improvements in address recording may assist efforts to retrieve these patients for treatment. Additional evaluations are needed of improved counselling of TB suspects to prevent initial default, and of reasons for death before treatment initiation.

Annual risk of tuberculous infection in Andhra Pradesh, India.

BACKGROUND: There is paucity of information on epidemiological situation of Tuberculosis (TB) in Andhra Pradesh. The DOTS strategy under the Revised National Tuberculosis Control Programme (RNTCP) was introduced in the year 2000 to cover the entire State by 2005. OBJECTIVES: To estimate the prevalence of tuberculous infection among children 5-9 years of age and to compute the average Annual Risk of Tuberculosis Infection (ARTI) from the estimated prevalence. METHODS: A cluster-sample house-based tuberculin survey was carried out in a representative sample of children between 5-9 years of age. The clusters were selected by a two-stage sampling procedure. At first stage, five districts were selected by probability proportional to population size (PPS) method. Depending upon child population ratio, 32 clusters allocated to each district were further sub-divided into rural and urban clusters selected by simple random sampling. A total of 3636 children, irrespective of their BCG scar status, were tuberculin tested using one TU PPD RT23 with Tween 80 and the maximum transverse diameter of induration was measured about 72 hours later. RESULTS: The prevalence of infection estimated by mirror-image technique using observed mode of reactions attributable to infection with tubercle bacilli at 20mm was 9.6% (95% CI: 8.0-11.2). The ARTI was computed at 1.4% (95% CI: 1.1-1.6). CONCLUSION: Survey findings indicate a fairly high rate of transmission of tubercle bacilli.

Diagnostic role of the antibody response to the 38kDa, 16kDa proteins and lipoarabinomannan of mycobacterium tuberculosis.

The antibody response to the 38kDa, 16kDa and Lipoarabinomannan (LAM) antigens ofMycobacterium tuberculosis was evaluated using three different ELISAs based on these antigens. The study group included tuberculosis patients (n=52), patients with HIV and TB co-infection (n=10), other chest symptomatics (n=5), HIV infected individuals (n=10), leprosy cases (n=7) and healthy controls (n=75). The results indicate that the 38kDa and LAM based ELISA for IgM/IgG has a low specificity (ranging from 69-85%) and sensitivity (ranging from 55-78%). When three ELISAs are carried out on a single patient the probability of detection of tuberculosis was significantly increased to 95.2% indicating that a single ELISA test is of low sensitivity and that a combination of ELISA's may be needed to be of any value as a diagnostic test for tuberculosis. Additionally, a western blot assay of the serum antibody response to protein fraction ofM. tuberculosis was analysed in 15 tuberculosis patients and five healthy controls. A multiple antibody response to various M.tuberculosis proteins was observed which varied from patient to patient as compared to controls who showed a single 38-39 kDa protein band positivity. These finding suggest that a western blot assay which determines the antibody response to a set of antigenic components ofM. tuberculosis could be a better serological test for the diagnosis of tuberculosis in our population.