A study was carried out to investigate the applicability of INH-Thiacetazone (TH) combination with special reference to acceptability and toxicity in Tumkur district. 150 patients from Tumkur town and some nearby villages were discovered during a mass Case-finding programme. Of them, 127 including 43 sputum positives were given chemotherapy with 300 mgm INH and 150 mgm thiacetazone (TH), in a single tablet to be taken once a day. All but one patient had the treatment on an ambulatory basis. Results of treatment in respect of 103 patients are presented in the paper.

The overall death rate was of the order of 15%. About twice the number of deaths occurred among the sputum positive patients than among the negative ones. About 40% of deaths occurred during the first quarter. In all, 23 patients developed side effects, in 18 of them thiacetazone had to be withdrawn. Serious side effects occurred among 5 (4%) patients. These patients did not report to the treatment centre by themselves and could not have been detected, if home visits were not made, thus giving an erroneous impression about side effects with TH. The sputum conversion at the end of one year was of the order of 50% among all survivors. Among those who were drug sensitive and examined at one year, conversion rate was 63%. Favourable radiological response was seen in 74%.

Thus, though cheap and clinically effective, Thioacetazone in combination with INH was found to produce serious and significant side effects. Hence, vigilance by the treatment centres were thought to be necessary when the patients are on this regimen.

The high rate of treatment completion and the regularity of drug intake achieved in clinical trials of Short Course Chemotherapy (SCC), could possibly be attributed to efficient organizational set-up, careful selection of cases and all-out effort to control defaulters. The organizational effort put forth to achieve the regularity is relevant to the applicability of SCC in the existing set-up of District Tuberculosis Centres (DTCs) under National Tuberculosis Programme (NTP). First 300 patients admitted to SCC trial to assess the efficacy of three drug regimens of 3/5 months duration under fully supervised conditions, carried out jointly by National Tuberculosis Research Centre, Madras and National Tuberculosis Institute (NTI), Bangalore, have been analysed for the purpose.

To keep up the regularity, 1/3rd of the patients required home visits-some of them repeatedly. If the actions of the same intensity of defaulter retrieval in the form of home visiting are envisaged to be taken in a DTC with the normal working pattern catering to 500 patients, 250 to 300 home visits will have to be made in a month. This may not be feasible in the existing set-up of NTP. A new strategy of defaulter retrieval actions for programme conditions may have to be devised. Further, selection of drug regimen which has the maximum potential of being given on self-administered basis may reduce the work-load to a considerable extent. Drug toxicity, side effects and the cost of drugs may not be major handicaps. However, the only way to understand various operational problems is to undertake scientific operational studies in actual working conditions of NTP.

An operational study of two regimens of Short Course Chemotherapy (SCC) to assess their efficacy under programme conditions, applicability and feasibility in District TB Programme (DTP) was undertaken in an urban TB centre. The two regimens studied were 1SHRZ/7TH and 2SHR/6TH. Their operational efficacy (efficiency) was found to be 87% and 92% respectively which had already been reported in an earlier paper. The various factors i.e., initial willingness, drug default, treatment completion pattern, adverse drug reactions and initial drug resistance with their potential harmful effects on the treatment outcome as well as work load and extra cost these regimens entail for DTP organisation are discussed in this paper.

Out of a total of 1822 smear positive patients diagnosed at the Lady Willingdon State TB Centre during intake period (Feb '84 to March '85), 1126 were residents of Bangalore City. Of these 695 (61.7%) were unwilling to attend the clinic daily for 2 months, 27 were unfit and one was excluded by mistake. Thus, 403 (38.3%) initially willing patients were classified either as 'core group' or 'Non core group’, according to the history of previous anti TB treatment (321 and 82 respectively). Of the 695 (77.6%) unwilling persons, majority were those who pleaded inability to attend daily for 2 months without specifying any particular reason. Refusal of SCC due to injections accounted for 12.8% and 9.5% wanted to take treatment elsewhere. Old age influenced willingness adversely.

Of the 321 patients in the core group, 56 were excluded due to missing more than 50% of intensive phase doses. Among the remaining patients, 61 (48%) out of 127 patients on Regimen A and 48 (34%) out of 138 on Regimen B, did not make a single default in the intensive phase. Of the total 910 defaults for which actions were taken, 640 (70%) were retrieved by letter writing, among the remaining 293 (72%) were retrieved by home visiting. Main reasons for default elicited during home visits were: going out of station (52.9%) followed by patients being busy with work (19.1%). Compensatory phase was availed by 156 of the 265 patients who missed one or more doses due to default in the treatment. The pattern of treatment completion of 321 core group patients in the two regimens were similar i.e., in both the phases 65% for Regimen A and 63% for Regimen B. Incidence of minor adverse reactions was 28% and major toxic reactions were experienced by 8.4% of patients. Workload for treating 321 patients was due to supervised administration of drug 45 patients per day. Letter writing to 3.1 per patients, home visiting 1.1 per patient and doctor's attention for adverse reaction 2 occasions per patient. This could be managed with the existing staff. The cost of Regimen A was Rs.220/ per patient and for Regimen B, 268/ per patient. Cost to patient for transportation was Rs.70/ and Rs.113/ for Regimen A and B respectively.The major disturbing finding of the study was initial low acceptability of about 40% for SCC. The home visiting which was crucial in increasing the completion rate in this study is usually not available in most of the DTCs. Workload, adverse reactions etc. were not of any problem for implementation of SCC in the programme.

In the BCG Mass Campaign low outputs and coverages of BCG vaccination done after tuberculin test were due to slowness of the campaign because of two visits to an area, the fear of two pricks and tuberculin tested absenting themselves from reading of the test. It was thought that if BCG vaccination could be given without prior tuberculin test and without causing any complications then the speed of work and outputs could be more than doubled and coverages improved appreciably. For this, the following three studies were carried out: In the first study 1,891 persons belonging to a rural population were randomly divided into four groups (i) those tuberculin tested and vaccinated, (ii) tested but not vaccinated, (iii) not tested but vaccinated, and (iv) neither tested nor vaccinated. Induration site of tuberculin test and vaccination were read on the 3rd, 6th and 90th day. Later on, another tuberculin test was done on the 90th day and read 3 days later. Both axillae were examined on 0, 14th and 90th day and X-ray pictures were taken on 0 day, 90th day and after one year. Tuberculin indurations on 3rd day were compared with BCG induration on 3rd, 6th, 14th and 90th day. Majority of tuberculin reactors had large BCG indurations upto 14th day. By 90th day very few persons have large indurations left. Among non-reactors also large BCG reactions were seen in 25%-53% of the persons. There were no differences as regards to the size of lymph nodes (regional reactions) between reactors and non-reactors; neither was there any evidence of exacerbation of existing disease nor any flaring up of dormant foci (Primary complex) in the form of new disease as shown by X-ray.

In the second study out of 1,520 persons from 4 villages, 1,186 were both tuberculin tested and simultaneously vaccinated. Examination of local reactions daily from one to nine days, on 19th and the 29th day, confirmed the findings of first study with regard to the local reactions. In this study neither axillae were examined nor X-ray pictures taken. In the third study, influence on acceptability of direct BCG vaccination due to large local reactions was tested. Twelve villages in Gubbi taluk of Tumkur district were taken in pairs. Vaccination of 2nd village of each pair was done after 1-4 weeks of the vaccination in lst village to observe the influence of BCG reaction on the people. Vaccinations were given to 5363 (64.2%) persons from the total registered population with Madras liquid vaccine. The large local reactions showed no adverse effect on the acceptability of BCG vaccination in the neighbouring villages, rather a slight improvement in BCG vaccination coverages with time was seen.