The purpose of this study was to find out whether the prevalence of infection in young children might be used as an index of the tuberculosis problem in a population. Tuberculin testing was done in a random sample of 2,883 children (0-4 years) in Bangalore city, of those 2,589 (89.8%) actually completed testing. A total of 4340 children were registered in 59 villages and of these 4090 (94.2%) were tuberculin tested. The villages were from Bangalore, Kolar and Mandya as these districts were within 100 miles from Bangalore city. The team went from house to house and made a complete registration of the children 0-4 years in the selected houses. Information on socio-economic status, density of population etc., was also collected before giving tuberculin 1 TU RT 23 with Tween 80.

The results of the study showed that prevalence of infection in 0-4 years age group of cantonment area was 1.6% and in the crowded city area 4.1% at 14mm induration level. In the rural population, the prevalence of tuberculosis infection was 2%. In the city, a positive correlation between tuberculosis infection and socio-economic condition was obtained while it was not seen in rural areas. It was not possible to establish any correlation between tuberculosis disease and infection either in rural or urban areas, as the population was not examined for the prevalence of tuberculosis disease.

The aim of modern Public Health Programmes, is a reduction in the total amount of disease in the community. The unit for treatment and cure is not an individual but a sick community. With this new aim, it becomes essential to know the size and extent of tuberculosis in the community as it will be helpful not for purposes of planning only but essentially for the assessment of their effect on the problem. An attempt is made to review the important features of the available knowledge about infection, morbidity and mortality through various surveys. (i) Prevalence of Infection: Tuberculosis infection is widespread in both urban and rural areas of almost all parts of the country. Nearly 40% of the population are infected. To avoid the effect of non- specific allergy and get a more reliable demarcation, tuberculin reactions of 14mm and more were considered as positive by National Tuberculosis Institute. (ii) Prevalence of morbidity: The prevalence of radiologically active tuberculosis in the population is likely to be 1.5%, Prevalence of bacteriologically confirmed diseases is 0.4%. Based on single sample of sputum examination, the prevalence of infectious cases in the country is probably an under estimate. About two million are infectious at any one point of time. (iii) Mortality: Deaths from tuberculosis in the country is not definitely known. The impression of clinicians that death due to tuberculosis have fallen sharply may not be true. Half a million deaths will appear an underestimate. About 250 per 1,00,000 persons i.e., one million deaths due to tuberculosis per year seems to be a reasonable estimate. (iv) Bovine Tuberculosis: Only a few cases in man caused by the bovine tubercle bacillus have been reported although 2.75% to 25% of cattle have been found tuberculin reactors.

To put in a nut shell, the problem of tuberculosis in India is a gigantic one and our means of fighting it with the single tool of BCG, do not even touch the fringe of the problem.

The objective was to establish the prevalence rates for tuberculosis infection, radiologically active pulmonary tuberculosis and bacteriologically confirmed diseases for different age and sex groups. Tumkur District in Mysore State consisting of 2,392 villages, 10 towns of was selected for the study. The district headquarter town Tumkur was excluded from the survey. Random sample of 62 villages and 4 town blocks having a population of 34,746 persons constituted the study population. All the individuals available in the registered population were given a Mantoux test with 1 TU RT 23 with Tween 80. Longitudinal diameter of induration was read 3-4 days after the test. At the time of tuberculin test, all persons aged 10 years and above were offered a single 70mm photofluorogram. For each picture read as abnormal, a spot specimen of sputum of the individual concerned was collected at the time of reading the tuberculin test. Age and sex distribution of infection and disease were studied.

Various parameters concerning the prevalence of infection and disease in the community were reported. Prevalence rate of infection in all ages and both sexes of the population was found to be 38.3%, radiologically active tuberculosis 1.86% and 0.41% sputum positive disease. The infection and disease increased with age; of the total diseased, half were in age group 40 years and more and about 2/3 among males.

Distribution of tuberculin test indurations were studied in relation to nutritional status of 930 rural children aged 1-4 years and 796 aged 5-9 years. Using Quetlet's Index, it has been observed that the distribution of indurations were similar in normal and malnourished children. By following Jelliffe's criteria of grading nutrition, no correlation was observed between the size of induration and degree of malnutrition. It is concluded that malnutrition in the community may not influence the prevalence rates of tuberculin infection based on such testing.

The National Tuberculosis Control Programme is in operation since 1962, and its quantitative achievement is being monitored indirectly through records and reports received from District Tuberculosis Centres. For direct evidence of impact of the programme, tuberculin surveys are useful in reflecting the recent epidemiological situations prevailing in the area. Tuberculosis being a disease of secular nature, a periodic follow up with five years (arbitrary) interval may be preferred over the continuous follow up, for finding the trend of tuberculosis situations in an area.

Keeping in view the importance of tuberculin surveys, National TB Institute (NTI) has evolved a surveillance system which can be adopted by any state in India. The state teams can be trained at NTI in registering population, tuberculin testing & reading, so as to carry out the surveillance in their respective areas. It is essential to create a central organisation for surveillance of tuberculosis using the tuberculin test. The centre would be responsible for technical & administrative support and monitoring. NTI could provide technical expertise in formulating the surveillance system, a training methodology and an in service training to the designated staff.

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.

A study was carried out in Bangalore city corporation area with the following objectives; when BCG vaccination is administered simultaneously with primary smallpox vaccination to infants; (i) whether any immunological interferences take place as indicated by the development of vaccination lesion and post-vaccination allergy due to BCG vaccination and the development of the local lesion (take rate) of smallpox vaccination; (ii) whether the incidence of complications are higher among those simultaneously vaccinated and, (iii) whether the population will accept a procedure involving two vaccinations. BCG technicians and the smallpox vaccinators registered all the eligible children after house to house visit and randomly allocated to three groups. A total of 789 children aged below one year were admitted to the study. While 315 were vaccinated simultaneously with BCG and smallpox vaccines (BCG on the right arm and smallpox on the left), 255 were vaccinated with smallpox vaccine only and 219 with BCG vaccine. All 789 children were followed up on the 5th, 21st, 90th and 93rd day of vaccination. The 5th and 21st day followups were to study the development and healing of smallpox vaccination lesions, whereas the 21st, 90th and 93rd day followups were for BCG vaccination lesions. The 90th and 93rd followups were for tuberculin testing and reading.

It was found that there was no evidence of immunological interference between the two vaccines when administered simultaneously i.e., the development of lesion of smallpox vaccination among the simultaneously vaccinated group was similar to the development of the smallpox vaccination lesion among the only smallpox vaccinated group and, the post-vaccination allergy due to BCG among the simultaneously vaccinated group was similar to the post-vaccination allergy among the only BCG vaccinated group. The complications due to vaccinations were very few and similar among the simultaneously vaccinated as compared to the other respective groups. The acceptability of simultaneous vaccination was higher than BCG alone. The above study has demonstrated that BCG and smallpox vaccinations can be administered simultaneously.

Health has been defined as the state of perfect physical, social and mental wellbeing which is somewhat an abstract definition. In this paper economics of health is measured through economics of sickness. Because sickness is experienced, it can be measured and it inflicts physical social and economic sufferings. In a community, economic prosperity is directly dependent on quantum of sickness and its prevention by health services. A sociological enquiry into part played by disease in the socio economic development of society was made by carrying out a study in two village population groups. The social investigators of NTI made deep probing questions to elicit presence of symptoms, action taken by them, money spent on treatment and the loss of wages. In first study observation participation technique was also adopted. The investigators lived in the village for four months. In the other study 20% households of those 22 villages which participated earlier in an epidemiological survey conducted by NTI, were interviewed.

Findings of two studies are combined and presented. Illnesses were classified into major and minor on the basis of clinical severity and the duration of symptoms. In both the studies 60% of all persons were asymptomatic during 2 months prior to the interview. About 18% had one minor illness, 13% had major illness and only 3% had one major and one minor illness. The quantum of multiple disease (3 or more) occurring in one person was less than 2%. Only 20% of living man days were spent as sick man days. The average annual loss on account of health reasons per family has been estimated to be Rs.90 and Rs.15/ per capita. The overall economic loss due to sickness, direct and indirect amounted to 3% of the per capita income in the poorer groups of villages and 6% in the economically more favourable placed villages. The material available here strongly suggests that the sizes of households will not have much influence over the sickness in the community. Another significant feature of this study was the phenomenon- of substitution within the family whenever the wage earner could not go to work. The evidence examined in this paper suggests that the actual economic loss is only 1/3 of the calculated loss. It also suggests that the overall cost of sickness to the individuals and family is far less than what is normally calculated and is influenced by the money available in the household.