A study was conducted in 1983-84 by the National TB Institute (NTI) in the districts of Dharmapuri (Tamil Nadu) & Ananthapur (Andhra Pradesh). Thirteen health personnel were trained in census taking, tuberculin testing & reading and data keeping etc., at the NTI according to the standard methodology. The trainees were repeatedly assessed and only those who achieved a reasonably high inter-reader correlation with the standard reader were chosen for the field work. Field work was carried out by these health workers and supervised by the team leaders of NTI. Children between 0-9 years were tested with 1 TU RT 23 with Tween 80 in tuberculin testing centres specially set up in each village and the reactions were read between 48 & 72 hours after the test. The tuberculin testing/reading coverage was very high. Of 6702 eligible children, 5904 (97%) were tuberculin test read.

Individual reading assessment carried out at Ananthapur and Dharmapuri for the State Field Workers (SFWs) showed that agreement with Standard Reader (SR) of NTI at three induration levels i.e., 10+ mm, 14+ mm and 18+ mm were very high. The demarcation line between infected and uninfected appeared to be about 18 mm. In Ananthapur, the agreement at 18+ mm was 99% and at Dharmapuri it was 100% for SFW, and 98.4% for SFW-2. The estimates of prevalence rate of infection were 9.3% - SFW V/s 9.7% - SR at Anantapur, 5.2% - SFW V/s 5.2% - SR and 7.2% - SFW.2 V/s 7.2% - SR at Dharmapuri. The study further showed that it was possible to train general health workers, within a period of 3 months to attain a high level of efficiency. The general health services can successfully organise on their own a programme of tuberculin testing in the community with proper liaison and supervision by some nodal agency. The training and field supervision responsibilities may be shouldered initially by NTI or another suitable organisation, till these nodal agencies come up.

The fate of patients with isoniazid (H) resistant pulmonary tuberculosis, treated with 3 different Short Course Chemotherapy regimens (Regimen A-1 SHRZ/7TH, Regimen B-2SHR/6TH, Regimen C-2EHR/4H2R2) was examined in two sequential studies. One hundred H resistant patients belonging to two groups-one without history of previous treatment(core group) and second with history of previous treatment >=15 days (non-core group), were followed up at the end of 12th, 15th and 24th/36th month of chemotherapy. Bacteriological favourable response among patients in the core group at the end of chemotherapy with Regimen A, B and C were 65.2% of 23 patients, 50% of l8 patients, and 57.1% of 18 patients respectively. The response among patients in the non-core group were 27.3% with Regimen A and 52.6% with Regimen B.

At the end of 24/36th month of chemotherapy, 62.5% patients in the core group and 2 out of 7 in the non-core group on regimen A and 68.7% patients on regimen C in the core group and 5 out of 15 in the core group and 41.7% in the non-core group on regimen B were culture negative. The relapses were significantly high in regimen B & C in comparison with regimen A. Thus, of the total 100 patients, 99.3% were eligible for examination (1 died during chemotherapy), 67 were examined and of them 37 (62.7%) were culture negative, 22 positive and 8 were dead. The development of drug resistance to rifampicin was directly related to the duration of its use.

Five districts in which short course chemotherapy (SCC) was introduced during 1987-88 (DTP-SCC) and an equal number of districts without an SCC programme (DTP-SR) but having comparable new sputum examinations performance (NSE) in 1986 were selected from the states of Gujarat and Tamilnadu. Data obtained by the monitoring cell of the National Tuberculosis Institute (NTI) for 15 consecutive quarters from the lst quarter of 1986 were analysed. It was possible to study operational variables: NSE, number of pulmonary patients diagnosed (TBP) and number of bacillary cases detected (BCASE). While the figures of first six quarters were used to represent pre SCC performance, those of the last six quarters depicted the post SCC scenario. However, the trend analysis has been done using the whole data.

The growth rates of NSE, TBP and BCASE were 14.1%, 1.7% and 13.0% respectively for DTP-SCC compared with 17.0%, 5.3% and 29% for DTP-SR. Both the DTCs and PHIs in DTP-SR showed negative growth in BCASE, inspite of their efforts as evidenced by increase in NSE and TBP, the introduction of SCC led to an increase in BCASE for both DTC and PHIs. While the PHIs in DTP-SCC showed increased efficiency in all the aspects (NSE 24.4%, TBP 19%, BCASE 16.7%), DTCs showed decreased activity in NSE ( -2.4) and TBP (-6.6%), indicating improvement at the periphery. Trend analysis corroborated the above findings.

The stimulatory effect of carbon dioxide (CO2) on the growth of tubercle bacilli was reported by a few authors. A study was done to see the effect of CO2 on primary isolation of mycobacteria on Lowenstein Jensen medium in terms of (1) positivity rate (2) improvement in the rate of growth in cultures and (3) contamination rate.

One thousand and five clinical specimens were inoculated, after processing by modified Petroff's method, onto LJ medium and incubated with or without addition of 10% of carbon dioxide. Of the total positive cultures, 30.8% grew only under 10% carbon dioxide and in 58.3% growth was first seen in that atmosphere. The results of this study show that (1) 10% carbon dioxide increases the yield of mycobacteria in primary culture (2) it stimulates the temporal growth rate resulting in reduction of lag period by one week (3) the increase in yield is largely from smear negative specimens and (4) there is no significant increase in the contamination rate to offset the stimulating effect on mycobacterial growth.

Under the National Tuberculosis Programme, Ziehl-Neelsen method (ZN) is the recommended procedure for AFB staining. However, at the Peripheral Health Institutions, the applicability of this procedure appears to be adversely affected due to non- availability of alcohol for heat fixing, heating and decolourisation steps. Hence, it has become necessary to look for procedures when the use of alcohol could be avoided completely. In this study, three different methods of cold staining, wherein the use of alcohol is avoided, have been tried in 489 sputum specimens. One set of smears was fixed with acetone (CSB method), the second set with candle flame (CSD) and third set was not fixed (CSC). All were stained by a modified cold staining procedure. The (a) sensitivity (b) specificity (c) degree of agreement with culture and the standard ZN method and also (d) applicability of these methods, were studied. All the specimens were subjected for culture and ZN smear examinations. ZN method was significantly superior to other methods. As far as the agreement with culture is concerned, ZN method was found to be superior to CSB method by 29.26%, to CSC method by 24.3% and to CSD method by 31.7%.

The sensitivity and specificity of various methods were: ZN-76.1%, 98.4%, CSB-72%, 96.6%, CSD-72.7%, 96% and CSC-76.6%, 96.9% respectively.