The paper has illustrated the use of mathematical model (epidemetric model) for the prediction of the trend of tuberculosis in a given situation with or without the influence of specific tuberculosis control programme. The paper also advocates the use of models for evolving applicable control measures by reflecting their interference in the natural trend of tuberculosis in control areas. These models were constructed by applying methods which have been developed and utilised in other social sciences.
The precise estimates of the various parameters entering the model must be available if realistic long term results are to be achieved through model methodology. The need for exact data regarding prevalence and incidence of infection and disease, necessitates longitudinal surveys in large random population groups. It is, however, the present authors firm opinion that it would be fruitful for almost any health department, to compare their best available epidemiological knowledge in a system of relationships in order to quantify their concept of the situation. Such an exercise in mathematics would, in any case, serve to sharpen the epidemiologists thinking and would lead them to appreciate what data they need most urgently. The model may help in predicting the trend of tuberculosis in a given situation.

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.

Limitations of a single X-ray picture for locating and interpreting shadows in the chest had been studied earlier. In order to reduce these limitations, it was suggested that two pictures of each person be taken where the second picture was to be taken after a vertical displacement of X-ray tube, up or down by about 4 to 5cms. The advantages of taking two pictures simultaneously as compared to a single picture have not been studied so far. Two mobile X-ray units each with an odelca camera were alternated for the single and double picture examinations. A total of about 2,000 persons were X-rayed and were read independently by 3 readers. A spot sample of sputum was collected 3-4 days later from persons with abnormal X-ray shadows and was examined by direct smear microscopy.

Comparison of the readings of the two sets of pictures did not show a better agreement between different (inter- individual) readers or between two different readings of the same reader (intra-individual) when the two picture technique was used. The X-ray cases detected by double picture only by any one reader were not confirmed, more often than those detected by single picture only. The X-ray pictures of the bacillary cases were also not interpreted more often as active tuberculosis by the two picture technique. It was concluded that the double picture technique does not offer any advantage over the single picture technique.

Generally there is no acceptable definition of the term “case of pulmonary tuberculosis”, although such a definition is of fundamental importance both in clinical medicine where results of various chemotherapeutic regimens are compared, as well as for the comparison of different epidemiological data. The main purpose of this paper is to focus attention on the difficulties of defining a case on the basis of bacteriological examination, X-ray examination and tuberculin test. Data from two successive prevalence surveys in a random sample of 134 villages in Bangalore district with a population 70,000 have been utilized to illustrate some of the difficulties in defining a “case” of pulmonary tuberculosis for reporting the prevalence or incidence of the diseases. The entire population was tuberculin tested with 1 TU RT 23 with Tween 80 at both rounds and those 5 years of age and older were examined by 70mm photofluorogram. The sputum specimens (spot and overnight) were collected from those with any abnormality on X-ray as recorded by either of the two independent readers. Both the specimens were examined by fluorescent microscopy and Ziehl-Neelsen technique and by culture.

Analysis of data has shown that the term “a case of pulmonary tuberculosis” does not represent a single uniform entity, but embraces cases of several types, differing considerably in their tuberculin sensitivity, results of X-ray and sputum examination, in the reliability of their diagnosis and mortality experience. The status of cases found at initial and subsequent surveys showed changes with time, and such changes show considerable differences for the various types of cases. It was felt that a single straight-forward definition of a case was not possible to suit all situations. One has to use more than one definition. Although theoretically, finding a single bacillus in sputum should be adequate proof of pulmonary tuberculosis, it was shown that finding of a few bacilli (3 or less) was very often due to artifacts and should not be the basis for a diagnosis. It has also been found that positive radiological findings, in the absence of bacteriological confirmation, indicate only a high risk of the disease and not necessarily pulmonary tuberculosis. Direct microscopy appears to be a consistent index of disease but in community surveys has the limitation of missing a substantial proportion of cases and of adding some false ones.

In view of the difficulty of providing a single definition of a case of tuberculosis, four indices have been suggested. (1) Cases definitely positive by direct smear; (2) Cases definitely positive by culture; (3) All cases positive by culture (including less than twenty colonies); (4) Sputum positive cases which are radiologically active. Each of these could be used for different situations. However, it was concluded that, there seems to be no option but to use more than one definition for assessing the prevalence and incidence of disease.

The degree of the risk of infection and disease in man from drug resistant strains of mycobacterium tuberculosis is not clear. An increase in the prevalence of primary resistance indicates the extent of such risk while an increase of secondary or acquired resistance could be considered as a problem of the individual patient and may reflect limitations of his treatment.

The present report describes the prevalence of strains with acquired or primary resistance or of sensitive strains found in 3 successive surveys in a sizable random sample of village in a south Indian district. Changes in the status of cases with such strains from one survey to another and their infectivity among household contacts are also described. The prevalence of tuberculosis infection among household contacts of cases with acquired resistance to isoniazid was significantly higher than those with primary resistance or with sensitive culture. This was probably due to the longer duration of sputum positivity of isoniazid resistant strains at the time of diagnosis. But infectivity as judged by the incidence of new infection among household contacts was generally less for cases with acquired or primary resistance than for cases with sensitive cultures, though the difference observed was not statistically significant. A large number of culture positive cases especially those with primary resistance had no radiological evidence of active pulmonary tuberculosis. The prevalence of primary resistance was high in certain categories of cases and the differences between cases with primary resistance and those with acquired resistance were many and large. It was suggested that this could be due to the primary resistant cultures being those of atypical mycobacteria, despite positivity in the niacin test. There was a significant increase in the number of cases with acquired resistance to isoniazid at the third survey owing to the irregular treatment and supply of INH alone after the second round. The prevalence of primary resistance at the three rounds was almost the same.

Prevalence surveys are useful for estimating the tuberculosis problem in different countries. Three techniques are commonly used in surveys, tuberculin test, mass miniature radiography and sputum examination. Each has its own limitations. A limitation of sputum examination is that all the sputum positive cases in the community cannot be diagnosed when only one sample of sputum is examined from each eligible person. Multiple sputum examinations are not often possible under field conditions of surveys covering the whole community. It would be worthwhile to have some idea of the extent of under-diagnosis in sputum examination. For this purpose, during an epidemiological survey, four specimens of sputum were collected within seven days of X-ray examination from each person with an abnormal chest X-ray in 30 villages of a district of south India. Each specimen was examined by Fluorescent Microscopy (FM), Ziehl Neelson (ZN) technique and culture.

There were 34 culture positive cases among 2,164 persons for whom all the four culture examination results were available. Of them, 21 (62%) were found positive on one specimen. The second specimen increased the positivity to 32 (95%). Thus, for detecting both smear and culture positive cases two specimens are adequate. A third specimen is helpful for detecting cases positive by culture alone. An estimate of prevalence obtained from one sputum specimen can be estimated for the prevalence obtained from many specimens by applying correction factor of 1.67 and estimates based on two specimens by applying 1.26. Of the remaining 37 smear positive cases detected by one specimen, 20 were smear positive and culture negative. Of the remaining 17 smear positive and culture positive, 14(82%) were detected by one smear examination only.

ZN positives not confirmed by culture (mostly with less than four bacilli reported in the smear) increased from 7 from the first specimen to 18 from all four specimens, while positives confirmed by culture method showed only a marginal increase from 13 to 15. FM did not have this disadvantage as only two were culture negative among the 18 smear positive results by FM method. Examination of two specimens by FM detected about 95% of cases demonstrable by this method. But with the ZN technique additional specimens may add more “false positives”. Thus, for detecting cases both smear and culture-positive two specimens appear adequate. A third specimen is helpful for detecting cases positive on culture only.

Data from 62 randomly selected villages in a district of south India, which formed part of a prevalence survey carried out by the National Tuberculosis Institute, Bangalore, during 1960-61, has been made use of. The survey covered 29,813 persons in 5,266 households. There were 70 cases with bacilli demonstrable either in smear or culture and 300 suspect cases. Using the village map (prepared by survey staff), ‘case clusters’ were formed first, with each case household as nucleus and adjacent households within a maximum distance of about 20 meters on either side of the case households. Households closest to the nucleus household on either side have been called as 1st neighbourhood and those coming next in proximity on either side as a 2nd neighbourhood and so on. The case household and its four neighbourhood together was called a cluster. If another case household was found within 4th neighbourhood of the first case the cluster was extended by including the 4th neighbourhood of the new case also. Such clusters were called composite case clusters and clusters with only one case household as simple case clusters. Similarly, suspect case clusters were formed and differentiated as simple suspect clusters or composite suspect clusters. Further, to serve as a control group, non-case clusters were constituted from a systematic sample of 10% households that were not included in case or suspect case clusters.

Out of 60 case clusters formed, only 7 have multiple cases showing that there was no evidence of high concentration of disease in case clusters. While the percentage of child contacts (0-14 years) infected was considerably higher in case clusters (25.8%), there was not much difference between suspect case clusters (14.9%) and non-case clusters (9.8%). Similarly, there was not much difference between simple and composite clusters. Infection among child contacts was higher in case households as compared to their neighbourhoods. To get some idea of the zone of influence of a case or suspect case, prevalence of infection was studied for 10 neighbourhoods, in simple clusters to avoid the influence of multiple cases. It appeared that the zone of influence of a case may extend at least upto the 10th neighbourhood. It was also noted that there was very little difference between zones of influence of suspect cases and non-cases. Case clusters in which the nucleus case had shown activity of lung lesion (evident on X-ray reading) or had cough showed significantly higher infection among child contacts. Clusters around cases positive on both smear and culture did not show higher infection than those around cases positive on culture only. (This may be due to sputum examination of single specimen only).

Out of the total infected persons in the community, only 2% were in case households and 7% in suspect case households, over 90% being in non-case households. The zone of influence of a case extending at least upto the 10th neighbourhood and the overlapping of such zones of influence of cases, present and past, seems to be the most probable explanation for the wide scatter of infection in the community. Prevalence of infection among child contacts was definitely higher in case clusters. But, the significance of this could be understood only from a study of the incidence of disease during subsequent years in different types of clusters. It is significant that only 10% of the total infected persons in the community were found in case clusters. The case yield in general population, cluster contacts, household contacts and symptomatics attending general health institutions have been also compared. The case yield in the last group (10%) is much higher than the case yield from both types of contacts (0.7% and 0.6%) which where only slightly higher than the case yield from the general population (0.4%).

During second epidemiological survey carried out in 1972-73, special efforts were made in 21 of 62 villages belonging to first survey (1961-62) to study the demographic changes and fate of TB cases after an interval of 12 years.

The findings were: The increase of dejure population was about 20% over a period of 12 years i.e., an annual increase of 1.7%. The age structure had altered mainly due to significant increase in the age group 60 years and above – 51% to 64% indicating aging of population. The loss of original population after 12 years was 44%, of which 33% was due to migration and 11% due to death. The overall migration was more among females. The migration rate was higher in younger age group, being highest in 10-19 years (49%), next in 0-9 years (38%). Thus, overall migration in 0-19 years was 43%. The death rate was highest in 60 years and above (58%). It varied from 4-9% in age group 0-39 years. Original population available after 12 years for re-examination was 56%. Distribution in different age groups were; 0-9yr = 57%, 10-19yrs = 47%, 20-49yrs = 66%, 50-59yrs = 44%, 60yrs and more = 28%.

Out of 88 X-ray suspect cases of earlier survey, 87 could be identified and present status of 72 were known. Of them, 16 were normal, 12 and 4 found to be suspect cases and bacillary cases respectively and 40 had died. Of the remaining fifteen, 11 migrated and 4 not examined. Out of 14 bacillary cases, 13 could be identified. Of them, 3 were sputum negatives (2 normal and 1 suspect case) 9 had died and 1 migrated.

Examination of only one sputum sample cannot detect all the sputum positive cases in the community. To obtain better estimates of the prevalence of bacteriologically confirmed disease in the community, a study was conducted to find out the additional yield of cases through collection and examination of eight sputum specimens and also in order to work out correction factors for estimates based on one or two sputum samples, as collecting multiple sputa is very difficult. The study was carried out in 77 villages in Nelamangala Taluk of Bangalore. In all, 5826 persons were referred for sputum examinations.

Results of all the eight culture examinations were available for 2973 (51% of the eligibles). Of these 64 persons were positive by culture of atleast one specimen. Each of the eight specimens has the chance of detecting a case and any one of them could be considered as first or second specimen etc. To overcome this difficulty 80 permutations were randomly chosen out of the total 40,320 permutations possible. Cases from first specimen and additional cases from subsequent specimens were calculated through four mathematical equations. The first equation namely Y = KXm (28.66 x-1.40) has been considered as providing the best fit to the observed data. On the basis of this equation it appears that additional positives could be obtained upto the 1Oth specimen. Out of 64 culture positive cases, only 72% of positives could be detected by first two samples. To get about 95% of the cases, it is necessary to examine at least six specimens from each individual. Multiple samples are rewarding for detecting even high grade cultures.

The five year longitudinal epidemiological study in south India (1961-68) showed that a considerable proportion of bacteriologically proven cases found in a survey got cured naturally without the facility of organised treatment in the survey area. This "natural cure" could be an epidemiologically significant phenomenon- depending on the stability of such a cure or in other words, the frequency of relapses among the naturally cured. In all, 108 naturally cured cases of tuberculosis out of a total of 269 cases, from among about 62,000 persons surveyed twice, were followed up for varying periods of 1 to 3½ years.

It was observed that the average relapse rate was 85.4 per 1000 person years of observation, there being no difference between the two sexes. Relapse rates were however higher in persons aged 20 and more compared to those 5-10 years old. Relapses were not dependent on the bacteriological status at initial diagnosis i.e., whether positive by culture alone or positive by smear and culture. The death rate among the naturally cured was 42.7 per 1000 person years and together with relapse constituted the unfavourable fate after natural cure. It has been calculated that as an input, adding to the pool of bacillary cases in the community, the ratio of relapse cases to cases arising afresh from the general population in a year would roughly be in the order of 1:16. It is concluded that the naturally cured status could be considered as an epidemiologically favourable situation, though much less so when compared to the chemotherapeutically achieved cure.

Because of slow nature of decline and the long span of the declining phase spread over a couple of centuries it is difficult to obtain direct evidences of decline by conducting studies over relatively short period of time and comparing the rates so obtained. Therefore, one has to take into account the total current epidemiological situation by considering both indirect and direct evidences to know the trend of disease; A) Indirect Evidence i) tuberculosis morbidity being largely confined to older age groups, prevalence rates being similar in both rural and urban areas and a wide gap between infection and disease rates (38% and 0.4% respectively). ii) Information on tuberculosis mortality although not very reliable, still appears to suggest that the disease, since the turn of the century, has taken a declining course. It has been observed to be 253 for 100,000 persons in 1949 in Madanapalle and 84 per 100,000 in Bangalore during 1961-68. There might he some regional variations but there is definite suggestion of decline in the mortality. iii) Considerable change in clinical presentation from more acute and exuberative to a more chronic disease and a shift in age during last quarter of the century, a marked decrease of the concomitant problems of pulmonary tuberculosis, are all indirect indicators of decline. B) Direct evidences are: i) Information available from various epidemiological surveys in India indicates no change in the prevalence rates of bacillary tuberculosis in the country during the last two decades. ii) The longitudinal survey conducted in south India and the other in Delhi have shown a declining trend of the disease specially in the younger age group. However, to see that the trend is secular or not, these surveys have to be continued for a longer period of time - atleast 15-20 years.

From the above evidences it may be reasonable to infer that there is a gradual but slow natural declining trend of tuberculosis in the country. To hasten the process of natural decline and to give relief to a large number of prevailing cases, anti tuberculosis measures should be further strengthened.

The problem in using simple tools e.g. chest symptoms for epidemiological surveys, designed to quantify the problem is that estimates from these simple surveys are considerable underestimates. Recent research has, however, paved the way for the use of these simpler tools for use in estimating tuberculosis case prevalence rates in the community. A tool which is simple, convenient to use and maintain, cheap but highly sensitive is called "screening tool". Such tools are used for making initial selection of the given population. Tuberculin test, X-ray & symptom elicitation are the main screening tools used for epidemiological surveys and TB Control Programme. In the programme, symptom elicitation and X-ray examination are the screening tools of choice for Case-finding. In the survey, tuberculin and X-ray are the only two tools used, although tuberculin is not a good screening tool (40% population infected). Use of symptom screening in surveys, however, is restricted in the absence of adequate information on comparison of prevalence rates obtained by this method of screening with the best estimate. The performance of symptom screening with either culture or smear microscopy have been attempted. They showed that by applying suitable correction factors they may be rendered comparable to the best estimate. The symptoms may be useful in the survey as a screening tool and may give the rates as proximate to the true rates as possible. They will enable considerable simplification of epidemiological studies in tuberculosis without compromising on the precision of the estimates arrived at.

Mortality from tuberculosis is an important epidemiological parameter for defining the problem of tuberculosis in any country. But due to lack of systematic recording and reporting system, precise information on cause of death is not available in our country. An attempt has been made to estimate the case fatality of tuberculosis cases as well as mortality of cases diagnosed in a longitudinal study conducted from 1961-68 in Bangalore district. Crude mortality of cases is defined as the ratio of total deaths observed among cases to the total number of cases observed, while case fatality is defined as the ratio of deaths that have occurred due to tuberculosis to the total number of cases investigated.

The overall observed annual crude mortality was 14.8%, while among culture positive smear positive (C+S+) it was 21%. An upward trend was seen with the increase in the age. The overall annual crude mortality among culture positive smear negative (C+S-) cases was 9.5% which is significantly lower than that among C+S+ cases. The death rates among old and new cases at the end of 18 months were 16.7% and 13.7% respectively. No statistical difference was found in the crude mortality either among old and new cases or in relation to the interval of diagnosis. Case fatality due to tuberculosis was computed by calculating the deaths among non-tuberculosis population of the same area and during same period and eliminated from the total deaths observed among tuberculosis cases. The case fatality of tuberculosis was found to be 13.3%. It was further observed that out of the total 38 deaths among cases, 89% were due to tuberculosis and 11% were due to non-tuberculosis causes.

It is a common observation that in epidemiological surveys all those eligible for various examinations (tuberculin, X-ray and sputum examinations) do not attend them. If the 'non-attenders' differ from the 'attenders' the true situation of the problem may not be known. In this paper, the prevalence of infection, bacillary cases and suspect cases at II survey for both attenders and non-attenders of the I survey from longitudinal study conducted by National Tuberculosis Institute, Bangalore, are compared.

It was observed that in spite of repeated attempts, nearly 1/5th of the population did not attend examinations. The non- response group during I survey was examined at the subsequent survey and both response and non- response groups at the preceding survey were compared. It was found that in respect of prevalence of infection and bacillary disease, the two groups did not differ, but the mortality and emigration was higher among the non- response group. Higher mortality among non-attenders may be due to the fact that the group contained more sick people. The higher emigration among non-attenders due to small error even to the extent of 0.5% at the stage of census taking by registering a non-resident as permanent resident of the village would highly boost the rate of emigration among non- attenders. The difference in the indices of crude mortality and emigration rates becomes narrower and narrower as coverages for examinations increase. The analysis indicates that every attempt should be made to obtain as high a coverage as possible in order to obtain valid estimates of epidemiological indices in a population survey.

Mass miniature radiography (MMR) is the usual tool for population screening in tuberculosis case prevalence surveys. However, this facility is not available at most centres in India. An attempt was made to study the feasibility of carrying out sputum positive case prevalence survey in a population by introducing methodological variation in the screening, in order to select those eligible for sputum test without resorting to the customary use of MMR for the purpose. The study was carried out in Bangalore rural district during 1984-1986. The area was the same as for six earlier prevalence surveys conducted since 1961. The population aged up to 44 years was tuberculin tested. Persons with test induration size of = 10 mm were eligible for sputum examination, besides all those aged over 45 years were eligible. It was observed that 78.4% of the registered population (29400) in the age group 10 years and above were required to undergo sputum examination by the present method of screening leading to a very high work load of sputum examination necessitating deployment of additional sputum cultures. Thus, the purpose of pre selection for sputum examination was hardly fulfilled. Further, a high contamination rate was observed. The changed screening procedure in this survey made comparison with the earlier data difficult.

The overall prevalence rate of cases was 438/100,000 in persons aged 10 years and above, while smear positive prevalence rate was 68/100,000. The observed prevalence rate was similar to earlier surveys, while smear positive prevalence rate was much lower. In conclusion, the screening methodology was found to be operationally unfeasible, ineffective and counterproductive to complicate the survey procedure in the quest for simplicity.

A comprehensive baseline survey was undertaken in two contiguous districts of Salem and South Arcot of Tamil Nadu for strengthening the health and family welfare services with the assistance of the Danish International Development Agency (DANIDA). The main objectives of the study were to obtain data on the prevailing health status of population, the village organisations and leadership in health matters and important aspects of the health system of the area, such as Primary Health Centre (PHC), Medical Officer (MO) and para medical personnel identified as field health workers.

a) Medical Officers: A questionnaire was canvassed by post mainly in June/July 1982 after briefing the Medical Officers at their monthly meetings at Health Unit Districts. Out of 221 posts of Medical Officers (MOs) in 72 Primary Health Centres (PHCs), 68 were vacant. Of the 153 MOs in position, replies were received from 119 (78%), 69 in Salem and 50 in South Arcot. Among these MOs, 87 were men and 31 women, and 71% were in the age group 30-39 years. Proportions of married were 87% in men and 71% in women. Of the 119 MOs, 111 were qualified in allopathic system of medicine. Though 52% stated that they had training in rural health services, only 26% mentioned that they were trained at Health & Family Welfare Training Centres (HFTC). About 50% of MOs had total work experience in Health Department of 1-4 years and 25% of 5-8 years. Of the average service of 4.62 years in this department, 3.09 years were in the PHCs where they were working at the time of the survey. The overall ranking of functions of MOs was 1) curative (60.5%), 2) Preventive (41.2%), 3) Promotive (23.5%), 4) Supervision (35.3%) and (5) & (6) Public relations (23.5% and 41.2% respectively). Administration had the highest percentage for 2nd and 4th rank. MOs trained in rural health, however, had given more importance to working with block officials as compared to other MOs. Though nearly 75% MOs had stated that they plan a weekly schedule of work, while giving the detailed schedule, a maximum of 48 MOs had included outpatient clinic on any day of the week and the position with regard to important managerial functions and rural services was much worse. About one third did not conduct any mobile clinic during the month prior to the survey; 28% did not answer the question and the remaining 40% had conducted 2 or more clinics. Most of them have provided curative treatment and not promotive or preventive services. About 43% stated that there were no voluntary organisations working in their area and more than 80% of MOs stated that private medical practitioners did not take any help from them. About 50% said that neither the private practitioners nor voluntary organisations participated in the health activities i.e., immunisation, health camps and family planning, conducted in the villages. About 22% stated that villagers did not participate in the health activities. While 23% had no difficulty in working at PHCs, 30% mentioned lack of facilities at PHC, 18% each stated personal problems, heavy work load/lack of staff and more administrative work and 16% transport problem. About 30% mentioned that there were no problems, 44% mentioned staff vacancies, 24% lack of cooperation from staff and 14% staff changes. While 47% found no advantage in working in a PHC, 27% mentioned about provision of better services to the rural areas, 18% about better understanding of basic health problems and 8% wider experience including management. About one third only gave the relevant suggestions for improvement of the centres. The MOs at PHCs can play a crucial role in the delivery of health services in rural areas. They are the leaders of the health team at the grass root level with adequate technical knowledge and a very high degree of acceptability. The findings of the present study are therefore, very valuable and the shortfalls and deficiencies listed below have to be given adequate attention: i) All posts of MOs and staff to be filled. ii) Provision of facilities to staff at PHC. iii) MOs should give more attention to public health activities. iv) Adequate supervision of work of MOs and special training to them in rural health.

b) Primary Health Centre: In the rural areas, Primary Health Centre (PHC) is the nerve centre of the health services both institutional and community oriented. It was planned to obtain some basic data on the organisational structure, area of responsibility and functioning of PHCs and utilisation by the people of the services provided by PHCs. All the 72 PHCs in the project area were studied through a questionnaire cum interview schedule. Further, data and clarifications were obtained through interviews from the Medical Officer In charge of PHC and knowledgeable staff such as Health Inspector (General) and Block Extension Educator. The data were collected during June 1983 to January 1984. The area of coverage of 82% of PHCs was within 300 sq. kms., 194 sq.kms in Salem (District I) and 237 sq.kms in South Arcot (District II). Thus, PHCs in South Arcot generally covered more area and more villages and served larger populations. About half of the PHCs could not provide information on scheduled caste and scheduled tribe populations who are part of the target population under the project. Out of 1175 sub centres for which information was available, 72% were within 20 kms. of PHC. This was so for 84% of 548 sub centres in District I but only for 62% of 637 sub centres in District II. The average distance of sub centres from PHC was 12.3 kms. in District I, 18.4 kms (one and a half times) in District II and 15.7 kms at project level. Organisation: The average number of villages per sub centre was almost the same in both districts (3.3 and 3.4). A sub centre covered an average population of 4,800. All but two PHCs were in standard building and all were electrified. Nearly half of the PHCs were located outside the village after which it was named. No other medical facility was available within one kilometer reach in 40% of PHCs in District I and 70% in PHCs in District II. Vacant posts were more among Medical Officers (37.6%) and Medical Officers (indigenous) (36.4) and less among para medicals (16% among supervisors and 10% among workers). While about one third of the PHCs did not have separate laboratory, about half did not have separate injection/dressing room and Minor OT. While most of the PHCs had refrigerator and microscope, 77% of the former and 93% of the latter were in working order. Functions: The main training activities of PHCs were Dais Training & Orientation Training Camps for which the average number of courses per PHC during the year prior to the survey were 3.1 and 2.6 respectively. Health education activities were mainly confined to group meetings and distribution of publicity material, with average annual performance of 70.3 and 53.8 respectively. Average outpatient attendance per PHC during the previous year was about 36,500 of which 19,600 were new outpatients. On an average, 98 patients were admitted in beds in a PHC (120 in District I and 71 in District II). For all the MCH activities except distribution of iron and folic acid to women and giving polio vaccine to children, District II had fared much better than District I. While for the other two activities mentioned above District I fared better. There was no uniformity between PHCs and districts in the number of tablets of iron and folic acid given per woman. Tuberculosis : The average percentage of persons with symptoms of TB was 1.8 (2.1 in District I and 1.5 in District II) as compared to the expected rate of 2.6% based on a study by the NTI. Identification of symptomatics from new out patients is on the low side, particularly in District II. As against the expected positivity rate of 10% among sputum smears examined, the rate was 14.4% (8.1% in District I and 21.4% in District II). The reason for such differences need to be studied in depth. Leprosy : Since leprosy work is carried out by special teams, most of the PHCs are not aware of the work done in their areas. Malaria : The average rate of fever cases identified per 1000 population during the month prior to the survey were 8.1% and 15.7% respectively. The figures for blood smears made were almost the same. The average number of persons given anti malarial drugs (mostly chloroquine) per 1000 population were 8.0 in District I and 20.7 in District II. Chlorination : In District I where a PHC covered an average of 51 villages, 84 wells were chlorinated during the month prior to the survey. The corresponding figures for District II were 111 villages and 89 wells chlorinated per PHC. Registration of births & deaths : The birth rate on the basis of births recorded by PHCs was 13.3 per 1000 which is less than half of the birth rate for Tamil Nadu for 1983. The recorded death rate was 8.3 per 1000 as compared to an expected death rate of 11.5. Recording of births and deaths needs considerable improvement in almost all PHCs. Referral : Among 64 PHCs who gave information on referral of patients for tertiary care, 21 referred to one hospital, 34 to either of two hospitals and 9 to anyone of three hospitals. Records & Reports : Surprisingly, PHCs gave a wide range of answers about the records and reports they maintain. Though there is a general complaint that records and reports are too many, there were hardly any useful suggestions about which records and reports could be simplified and reduced. Targets : Another surprising finding is that there was no unanimity in the answers from PHCs about the units of period for achieving targets under national programmes. Supervision : With regard to supervision of non- medical staff at PHC there was no uniform pattern. Medical Officers carry out field visits mainly for either control of epidemics or to pay surprise checks. Collaboration : Most of the PHCs did not seek collaboration of other Government departments, voluntary organisations or community leaders. The limited collaboration sought was mainly for Family Welfare Programme. Only about 60% of PHCs felt that the community can participate in Immunization, 52% in Family Welfare and 15% in Epidemic Control. Most frequent illness : Conditions affecting digestive and excretory systems were mentioned as the most frequent illness in their area by 38 out of 68 PHCs, followed by conditions affecting respiratory system by 32 PHCs, pyrexia of unknown origin by 20 PHCs, and skin diseases by 14 PHCs. Health problems : When asked about the health problems in villages, replies from PHCs dealt with diseases (illness) problems only.

The main weakness of the PHCs was observed with regard to management, inter departmental collaboration and community involvement as reiterated below: At least 40% of PHCs did not have 1981 census figures for population. Further, about half of them did not have population figures for scheduled castes and scheduled tribes. Recording of births and deaths are far from complete. Further, there is considerable indifference towards maintenance of all records and reports. The Medical Officers In charge, do not supervise the other Medical Officers of PHCs. Their knowledge about functions of para medical staff was inadequate. Under these circumstances neither could the Medical Officer In charge ensure adequate and proper supervision by the para medical supervisors nor guide them in their work. Acute shortages of Vitamin "A" and general medicines were reported. So also for mass media equipments such as film projector and sound system. Collaboration with other departments and voluntary organisations was quite weak. Contacts with community leaders either to understand the health problems as conceived by them or to seek the co-operation of the community were also at a low ebb. IUD insertions which benefit the younger couples or those with small families were quite negligible and the stress was on sterilisation only which benefit mainly older couples or those with already large families. Health education activity of PHCs was at a very low ebb.

c) Field Health Worker : The field health workers who consists of Health Workers (HWs) and Health Supervisors (HSs) were identified as important para medical workers. They play the most crucial role as they have daily contact with the rural population in their homes. The main objectives were to obtain a profile of field workers, to ascertain the area of responsibility, health services rendered by them, community responsibilities and supervisory functions of the HSs. The information was collected through pretested interview schedule. Of the 326 HSs and 2349 HWs in position, 165 were interviewed. The majority of male HWs were of age 30-39 years, while female HWs were of age 20-29 years. All the HSs and all but one of the male HWs were married. Among female HWs, half were married and about 88% of female HSs were married. Vast majority of HWs and HSs had education upto secondary level. The pattern with respect to these profiles was similar in both the districts. Of the male HWs 65% and of the female 32% had training in multi purpose work. While 83% of male HSs and 45.5% of female HSs had multi purpose work training, supervisory training was received by only 1.8% of male HSs and 9.1% of female HSs. With regard to total experience in the health and family welfare department, male HWs had more experience than female HWs. The difference was even bigger in average years and experience between male and female HSs. On an average, 6 villages were allotted to male HW and 4 to female HS, a male HW had to cover an average of 2291 families as compared to 1014 for a female HW. On an average, HW had to travel 6.8 kms to cover the villages allotted. The male HWs approached the villages by cycle or walk while female HWs by walk and bus. Availability of trained dais in the villages was reported by 40.9% of HW(F)s as compared to 50% of HW(M)s. Similarly, according to them about half of the villages have community leaders. Contact of HWs with such bodies need improvement. To the question on number of patients attending SHC services, 80% did not give an answer. The average attendance by HW(F)s was 7. Services given by HWs in villages allotted were malaria, FP & HE. The services received lower priority were TB, environmental sanitation, school health and registration of births and deaths. While 76.3% of HW(F)s maintained that they have a weekly schedule, only 46% of HW(M)s have weekly schedule. On an average during a month HW(F)s worked for 22.4 hrs and HW(M)s for 23.0 hrs in the village. On an average, 12 households are covered per hour. About three fourths of HW(M)s stated that they carried paracetamol to the village, 19.2% sulpha guanidine and 15.4% chloroqine. Among HW(F)s, 76.3% carried anti anemic drugs, 68.4% multi vitamin tabs and 47.3% anti malaria drugs. No medicine was carried by 44.3% of HS(M)s, and 24.2% by HS(F)s. Only 54% of HW(M)s and 74% of HW(F)s mentioned that they provided family planning services in the villages. Supervision of FP work by HSs is also very poor. Few HWs and HSs carried nirodh, oral pills or FP register when they visited the villages. Complaints that the high target for FP hampered health activities appears to be a cover up only. About 45% to 69% of health workers and supervisors said that TB work was not applicable to them. Similarly 42% to 50% also mentioned that nothing to be done for diagnosis of leprosy. Regarding the aspect of their work which are supervised by their supervisors, many did not reply and the others gave a variety of isolated answers. There is urgent need to give training to medical officers and health supervisors on how to carry regular qualitative supervision. The HWs make frequent visits to PHCs, some of them going once a week. This may interfere with the actual work in sub centres.

d) Trained Birth Attendant : In spite of the request to the PHC staff and village leaders to ensure that the trained dais of the selected villages were present, only 24 out of the 80 Dais were present during the survey. They were interviewed. About 54% of them belonged to families in which women attended to births by tradition. About 63% were illiterate, 29% had a monthly income of Rs.100/ or more. Fifteen belonged to backward classes seven to SC one each to ST & Christianity. Two thirds were trained before project started. Over 90% had experience of 5 years or more. Only two thirds of the trained dais have received the kits and less than half had received practical training in conducting deliveries. Different aspects of ante natal care were mentioned as follows: 82% periodical check up, 59% tetanus toxoid and 46% iron and folic acid. The number of deliveries conducted by trained dais was the same as before and after training. Majority of dais do not report births to health personnel. About 75% of the trained dais had referred at least one woman for delivery to ANM or hospital during the previous month. Eleven of the 24 dais, had no difficulties in carrying out their work while an equal number mentioned inadequate regular income. Trained dais were mostly aware of ANMS but not of Basic Health Worker, Malaria Worker or Health Inspector. Neither educational status nor experience had any influence on the functioning and working pattern of the trained dais. There were equal number of untrained dais, it would be worthwhile to train them also. Dai is important liaison between PHC and village for child births, post-natal care, family planning and registration of birth. Some future thought had to be given about their regular income, providing of kits, the replenishment and supervision during frequent visits by Health Workers and Health Supervisors. This will go a long way in ensuring co-operation from trained dais and in boosting up the morale of these village level workers of low socio economic standing which will make them useful participants in grass root level health activity.

e) Village Appraisal : Appraisal of the villages with their multi sectoral needs and activities would provide a third dimension to the survey. An appraisal of sample villages was conducted along with the household survey during June-November 1983. The method of group discussion was adopted to collect the data for village appraisal. Group discussions were held separately for SC & ST so that they could express their views freely (Adi Dravida colonies). This report is based on the information collected through group discussions in 71 main villages and 35 Adi Dravida(AD) colonies. About 45% AD colonies did not generally avail of services at PHC and one fifth did not avail of any service from HWs. Most of the groups felt that allopathic doctors were accessible to them followed by homeopaths. Contrary to expectations accessibility to practitioners of Indian system was poor. ANMs were more accessible to main villages than AD colonies. More than three fourth of main villages and AD colonies stated accessibility of dais. Most of the general facilities were accessible to a large extent except community centre and library. One of the main source of water was pucca well for three fourths of people. About 40% mentioned kutcha open well or river/canel. Latrines were few. Open field was generally used. Both manure pits and scattering was used for disposal of refuse to a large extent. Nearly all let out sullage to open places. About 50% of the villages mentioned that there was no developmental activity during last 12 month period prior to this appraisal. The activities mentioned more frequently were mid day meal scheme, water supply, school building, road construction and health centre. Most of the villages were not aware of who had taken the initiative for these activities. About 10% stated that there were no TB & leprosy cases among them while most of them mentioned DTC, general hospital or PHC as source of treatment of TB. Major problem of the villages were lack of water, transport and communication. Others mentioned were facilities for treatment and for education. Participation of women and younger generation in the group discussion was more in AD colonies than in main villages. According to villagers fever was the most common illness, followed by gastro intestinal disorders, diseases of respiratory system and eye complaints. Main causes of ill health were lack of sanitation and protected water supply. The perceptions by villagers pointed out the need for not only improving the availability and accessibility of service facilities but also for educating the villagers about how these could be made use of. The bigger and most important gaps would appear to be the provision and/or utilisation of preventive and promotive services, in availing of treatment facilities at PHCs and in reporting of births and deaths. Community involvement in all development activities would lead to informed participation in all developmental activities.