survey was 523/100,000. The estimated prevalence of pulmonary tuberculosis in 1989 was thus 528/100,000 after the estimation by means of annual reduction rate (0.9%). The weighted mortality from pulmonary tuberculosis in 1989 was 19.3/100,000. Based on the following formula: Fatality = Motality/Prevalence, the fatality of pulmonary tuberculosis in 1989 was 3.7%.
The causes of death among 776 tuberculosis patients were as follows: 294 cases (37.9%) died from pulmonary tuberculosis: 20 cases (2.6%) - extra-pulmonary tuberculosis: 437 cases (56.3%) - non-tuberculosis diseases. There was no any pulmonary tuberculosis cases died from thoracic surgical operation.
The cause of death in 44.2% patients among 294 patients who died from pulmonary tuberculosis was chronic cardio-pulmonary insufficiency and hemoptysis came next (30.3%). 18.0% died from general failure.
Among 314 patients who died from tuberculosis, the cause of death was confirmed by autopsy only in two cases (0.6%) and none of them was confirmed by pathological examination. The cause of death was defined on clinical basis in 148 (47.1 %) patients and on conjecture by the investigation brigade in 126 (40.5%) patients.
EVALUATION OF TUBERCULOSIS CONTROL MEASURES
? CASE-FINDING
1. Proportion of Newly Detected and Known Cases
The whole country: In this survey, the proportions of known cases among total detected pulmonary tuberculosis, bacteriological positive cases and smear positive cases were 37.2%, 47.1 % and 52.0% respectively and the proportion of new cases were 62.8%, 52.9% and 48.0% respectively. In general, about 50% of the bacteriological positive or smear positive patients have not been detected before this survey. The proportion (52.0%) of known smear positive cases in the survey was lower than that in 1979 (55.8%) and 1984/85 (56.4%) surveys.
Different age group: 0-14 age group had the lowest proportion (10%) of smear positive patient; age group above 60 years old came next - 39.1 %. The proportion in other age groups was all >50%. The highest proportion. (62.8%) was in 30-44 age group. The distributions of proportion by age groups in three surveys was basically similar.
In provinces, municipalities and regions: Qinghai had the highest proportion (70.0%) of known smear positive patient and Heilongjiang (69.0%), Liaoning (67.2%) followed. Shanghai had the lowest proportion (11.8%) and Beijing (33.3%), Guangdong (35.3%) came next.
There are two possibilities which induced a higher proportion of known cases in some provinces: firstly, the case-finding activities might be better; secondly, the case-management on chemotherapy applied to those newly detected cases might be insufficient and have induced a large amount of re-treated patients or chronic infectious cases.
There are also two possibilities which induced a lower proportion of known cases in some provinced: firstly, the case-finding activity in those provinces where the tuberculosis control programme have not been fully and effectively carried out might be insufficient and a large amount of existing cases have not been detected: secondly, in those provinces where the tuberculosis control programme have been fully and effectively carried out, most of the newly detected patients especially new smear positive cases were cured within a short period after the extensively application of the short-course chemotherapy; those cured cases were discarded from tuberculosis registration; in this cases, the number of known cases will also be very small in number and induced the situation that the percentage of new cases the among registered cases was rather high and the known cases were relatively low.
City and countryside: The proportion of known pulmonary tuberculosis and known smear positive patients in city in all three surveys was higher than that of town and countryside. The proportion of known smear positive cases in city, town and countryside in this survey was all lower than that in 1979 survey and showed 20.6%, 13.0% and 1.7% decrease in city, town and countryside respectively. City showed a big decrease and countryside small. The proportion of known cases showed a rugular shifting in the past years: it shifted from lower to higher and then from higher to lower. Such fact is a regular trend in the tuberculosis control process.
2. Mode of Detection Among Known Cases
The whole country: 97.5% of the known bacteriological positive cases and 97.8% of the smear positive cases were detected by clinical consultation. The proportions of know bacteriological positive patients detected by routine health examination and suspect examination were 1.0% and 0.8% respectively; the corresponding proportions in smear positive patients were 1.5% and 1.4% respectively.
Comparing the results in three surveys, the proportion of known smear positive cases detected by clinical consultation had increased. The proportions in 1979, 1984/85 and 1990 surveys were 89.5%, 94.2% and 97.8% respectively. The proportion of routine health examination had decreased in three surveys; they were 7.1&, 2.7% and 0.8% respectively. The proportion of suspect examination showed no significant change during these 11 years and was fluctuated from 1.0% to 1.4%.
In provinces, municipalities and regions: Among 29 provinces, municipalities and regions, 100% of known smear positive cases were detected by clinical consultation in 17 provinces, municipalities and regions: 92.0-98.5% in 10 provinces and regions. The corresponding proportions in Neimeng and Qinghai were 82.9% and 85.7% respectively.
In comparison with the results in 1979, only five provinces and regions whose proportion of clinical consultation was 100% in 1979 and theses increased to 19 in 1990 survey. The routine health examination was carried out in 17 provinces, municipalities and regions in 1979 (Liaoning had the highest proportion - 27.8%): these decreased to 5
