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A new case-finding programme in a region of Taiwan
Tubercule (1974) 55, 12 1
A NEW CASEFINDING
PROGRAMME
IN A REGION OF TAIWAN
By HSIAO-WENLUAN* from rhe Taiwan Provincial
Chiayi Tuberculosis
Cenfre, Chiayi,
Taiwan, R.O.C.
Smnmary
Sputum examination by house-to-house collection and chest radiography by a mobile unit of people with respiratory symptoms have been used in a new case-finding programme in Chiayi Region of Taiwan. Lay tuberculosis workers were employed to visit the houses, collect and examine sputum specimens and organize the radiography sessions. The mobile x-ray unit visited each area twice a year. During 1971, 512 villages were visited and 20,452 adults with respiratory symptoms registered. One hundred and forty-four persons with sputum positive on microscopy were discovered by the house-to-house sputum collection. A further 86 microscopy-positive were found by examining sputum from those with x-ray abnormalities and 51 positive only by laryngeal swab culture. Thus, 281 bacteriologically confirmed cases of pulmonary tuberculosis were found (9.0 per 1000 registered), 51 ‘A at the first home visit. The method allows both rapid identification of sources of infection in the community and later identification of bacteriologically positive cases among persons who were unable to provide sputum specimens initially. Of the total of 230 with sputum positive on microscopy, 63 % were found at the first home visit and chemotherapy could be started without delay. RESUMÉ L’examen des crachats après collecte de maison à maison et la radiographie pulmonaire par une unité mobile des sujets présentant des symptomes respiratoires ont été utilisés au tours dun nouveau programme de dépistage dans la region Chiayi de Taiwan. Des travailleurs auxiliaires de la lutte antituberculeuse ont été employés pour visiter les maisons, recuellir et examiner les échantillons de crachats et organiser les sessions de radiographies. L’unité radiographique mobile visitait chaque zone 2 fois par an. Au tours de 1971, 512 villages ont été visités et 20.452 adultes présentant des symptômes respiratoires, répertoriés. Cent quarante quatre sujets avec des crachats positifs à la microscopie ont été découverts par la collecte des crachats de maison à maison. Quatre vingt six examen positifs supplémentaires ont été trouvés par l’examen des crachats des sujets présentant des anomalies radiographiques et 51 ont été positifs seulement par culture après écouvillonage laryngé. Ainsi 281 cas de tuberculose pulmonaire bactériologiquement confirmées ont été trouvés (9,0 pour 1000 sujets répertoriés) dont 51% lors de la première visite à domicile. Cette methode permet à la fois une identification rapide des sources d’inffection dans la communauté, et plus tard l’identification des cas bactériologiquement positifs parmi les sujets qui étaient incapables de fournir d’emblée des crachats. Sur le total de 230 sujets avec des crachats positifs a l’examen microscopique, 63 % ont été dépistés à la première visite à domicile et la chimiothérapie a pu être commencée sans délai.
*presentaddress: Taiwan Provincial Tuberculosis Control Bureau, 10 Chingtoi Road West, Taipei, Taiwan, R.O.C. D
122 RESUMEN Para un nuevo programa de búsqueda de cases en Chiyai, Provincia de Taiwan, se emplearon exámenes de esputos en coleccidn a domicilie y radiografías de tórax con un equipo móvil en los individuos con síntomas respiratorios. Se emplearon trabajadores laicos para visitar las casas, recoger y examinar los esputos y organizar los exámenes radiográficos. Los equipos móviles radiográficos recorrieron cada area dos vetes por año. En 1971 fueron visitados 512 pueblos y se registraron 20452 adultos con síntomas respiratorios. Por medio de la colecta domicilaria de esputos se descubrieron 144 personas con baciloscopia positiva. Otros 86 cases fueron descubiertos al examinar los esputos de pacientes con alteraciones radiográficas; en 51 cases se halló positivo el cultivo del hisopado laringeo. En total, se hallaron 281 cases de tuberculosis con confirmación bacteriológica (9 por 1000 de los registrados), y el 51 x, en la primera visita domiciliaria. El método permite una rápida identificación de las fuentes de infección en la comunidad asi coma el descubrimiento ulterior de cases con baciloscopia positiva que no pudieron obtener esputos inicialmente. Del total de los 230 cases con baciloscopia directs positiva el 63 % fue descubierto en la primera visita domiciliaria y se pudo iniciar la quimioterapia de inmediato.
ZUSAMMENFASSUNG Im Rahmen einer Fallfindungsaktion in der Provinz Chiayi (Taiwan) wurden Sputumproben in der Wohnung eingesammelt, auflerdem Röntgenaufnahmen von Personen mit Beschwerden vonseiten der Atemwege durch eine mobile Röntgeneinheit angefertigt. Laienkräfte wurden eingesetzt, urn die einzelnen Haushalte aufzusuchen, das Sputum einzusammeln und die Röntgentermine zu organisieren. Die Schirmbildeinheit suchte jeden Bezirk zweimal im Jahre auf. 1971 wurden in 512 Dörfern 20 452 Erwachsene mit Symptomen seitens der Atemwege registriert. Einhundertvierundvierzig Fälle mit positivem Sputumausstrich wurden durch die Sputumaktion entdeckt. Weitere 86 positive Ausstriche gab es durch SputumuntersuchungdernTrägervonpathologischen Befunden im Röntgenbild, ebenso 51 positive Kulturen vom Kehlkopfabstrich. Insgesamt wurden 281 Fälle von bakteriologisch bestätigter Lungentuberkulose gefunden (9,0/1000 Registrierte), 51% davon durch den ersten Hausbesuch. Mit dieser Methode lassen sich sowohl die Infektionsquellen in der Bevölkerung schnell identifizieren als auch die bakteriologisch positiven Fälle unter den Personen herausfinden, die anfangs kein Sputum produzieren konnten. Von 230 Fällen mit positivem Sputumausstrich wurden 63yi durch den ersten Hausbesuch erfaBt; hier konnte die Behandlung ohne Verzögerung eingeleitet werden. Introduction During the past 22 years the three main measures for tuberculosis control in Taiwan have been BCG-vaccination, detection of previously unknown cases and chemotherapy. Because of the changing epidemiological, social and economie situation as wel1 as the availability of personnel, the tuberculosis control programme has had to be changed from time to time to meet the actual existing conditions. In the first 10 years case-finding was mainly by chest radiography of organized groups such as school-children, students, factory workers, government employees and military personnel. In the next 10 years the emphasis shifted to unorganized civilian groups, as it was considered that these would yield more tuberculosis cases. This is the so-called ‘community-wide case-finding
CASE-FINDING
IN
123
TAIWAN
programme’. Only during the past 2 years have sputum examinations in combination with selective chest radiography been developed. These 2 methods have their pros and cons (Baily and others, 1967; Hsing, 1967; Chu, 1968). They have been evaluated in Taiwan and reported at the VIIth Eastern Regional Conference of the International Union against Tuberculosis (Luan, 1972). In 1969 it was more costly to use miniature radiography on a community-wide basis (Table 1). To find one infectieus case tost NT $2,987 (US $74.4). By sputum examination without radiography it tost NT $1,415 (US $35.4). Selective radiography, examining only those with respiratory symptoms, was the least expensive - only NT $494 (US $12.4) for each infectieus case. To carry out selective radiography it is, of course, necessary to bring together al1 those in the community who have respiratory symptoms at the time when the mobile x-ray unit is due to arrive at the locality. The most dangerous sources of infection in the community are people with a positive sputum on microscopy; and these are mostly among the middle-aged and old. Such cases should be discovered without delay by sputum examination. But not al1 who cough can produce sputum at the time required; and some infectieus patients wil1 have a negative sputum at the first examination. Without too great an increase of tost, the two least expensive procedures - sputum examination and selective radiography - can be combined. This is the basis for the case-finding programme in Chiayi Region.
Chiayi Region Chiayi Tuberculosis Centre is located in Chiayi City in the South-centra1 part of Taiwan (Figure 1). It is responsible for a region consisting of 3 counties embracing 70 townships and has an area of 5245.8 sq km and a population of 2.5 million people. There is one health bureau in each county and one health station in each township. They are responsible for the total health programme in the community. Because Taiwan has not yet been wel1 industrialized, most people are stil1 living in the countryside TABLEIK---THEOPERATIONALCOST OF THREECASE-FINDINGPROGRAMMES IN TAIWAN IN 1969
Number of examinations Suspected tuberculosis - cases Infectieus tuberculosis - cases
Community-wide miniature radiography
Selective miniature radiography*
Sputum examination alone
13,149 497 48 3.6 per ICKNI
5,896 420 150 25.4 per 1000
16,901t 202 12.5 per 1000
Total tost Manpower CNT db)8
X-ray Sputum
72,775.0 26,625.0
37,395.0 11,155.o
280,800.O
Materials.
X-ray Sputum
40,917.o 3,079.o
19,679.O 5,896.O
5,070.o
10.9 228.7 2,987.4
12.6 135.9 494.2
16.9
~~~ Unit rost (NT I)
One examination One suspect case One infectieus case
1,415.2
*Radiography only for those with respiratory symptoms. tThe 16,901 specimens were from 16,154 persons (14,988 age 45 years or more and 1,166 age less than 45). &IONT $=l US b.
124
LUAIï
and most are working in agriculture. The population of a township The people live in 15 to 25 villages which are almost evenly scattered The health station is usually located in the largest village where the usually in the centra1 part of the township geographically, except portation is very convenient. Two hours by bicycle is the longest to the most remote village.
varies from 20,000 to 40,000. within the township boundary. township office is situated. It is in the mountain areas. Transdistance from a health station
The New Control Programme Tuberculosis control is fully integrated into the genera1 health service. Each health bureau has its own tuberculosis control work which is carried out by its regular staff. In order to increase the manpower for tuberculosis control in the peripheral health units, high school graduates have been recruited since 1966. They are trained for 3 weeks in the principles of control and the techniques of microscopic examination of sputum smears. They are assigned singly to selected health stations for case-finding work and also to help supervise domiciliary chemotherapy in the community.
Yangmingshan Admin. District
Keelung City
Chiayi Region: Area: 5245.82 Sq. Km Population: 2.5 Million (1970) County Health Bureaux: 3 Township Health Station: 70
b-!
/
_,[aitung C. ! / !7
FIG. 1 Map of Taiwan showing the Chiayi Region.
CASE-FINDING
IN
125
TAIWAN
Since 1971 the lay tuberculosis workers have been requested to carry out the new case-finding programme in their own community in the following four steps: 1. Find out the name, location and population of al1 villages in their township. 2. Group the villages into 3 to 6 clusters, the population size in each cluster being limited to 8,000 to 10,000. 3. Get census material from the census unit of the township office including name, age, sex and address of al1 inhabitants above 30 years. 4. Visit these people house-by-house and register those aged 30 to 59 with respiratory symptoms and al1 people 60 years and above. Collect sputum for direct microscopy if they can produce it. Give treatment to smear-positive cases promptly. Summon those people with respiratory symptoms but without sputum available, those whose sputum was negative by direct smear and all people above 60 for mass miniature chest x-ray examination on the day when the mobile unit is scheduled to come. They are asked to complete such case-finding activities for one cluster in the first six months, and the second in the next six months. The mobile x-ray unit is sent twice a year to each health station. It is hoped to complete one round of such screening in 2 to 3 years for each township. Results
Although Chiayi City is equivalent to a township within Chiayi County administratively, it is really a large city with a total population of 242,662. So it is excluded from this programme. Another two townships, Wufeng and Ta-pu, in Chiayi County are located in a mountain area; they were also excluded because of the difficult access for the mobile x-ray unit. Two townships in Tainan County failed to participate because no lay tuberculosis worker was available. Through the whole year of 1971, 65 townships actually participated in this programme. There were 2,337,994 people living in 1,240 villages in 3 counties in Chiayi region (Table 11). Five hundred and twelve (41.3 %) of 1,240 villages had had completed visits by lay tuberculosis workers in the year 1971. Out of 203,027 adults aged 30-59 years, 20,452 (10.1%) with respiratory symptoms had been registered, and out of 46,162 aged 60 years or more 10,995 (23.7%) had been registered. A total of 31,407 persons with symptoms were registered during the house-to-house visits. Two hundred and eighty-one people with a positive sputum were discovered (9.0 per 1000 registered) (Table 111). Examination of sputum smears collected at the visits by the lay workers discovered 144 cases (51%). Another 86 (31%) were discovered by sputum smear examination after the chest TARLEIT.-REGLWRATIONDURINGHOUSE-TO-HOUSE Vrsrrs BY LAY TUBERCULOSISWORKERSIN 1971
/!
Registration
_~
and visitation
Age 30-59 Population
Total
-.
of
597,196 801,842 938,956 2,337,994
in 1971
--
Age 60 and more years
No.
%
No.
% with symptoms
No.
% with symptoms
341 382 517
131 137 244
38.4 35.9 47.2
58,396 62,132 75,499
8.2 13.0 8.8
12,876 15,238 18,048
23.7 26.5 21.4
1,240
512
41.3
203,027
10.1
46,162
Villages
villages
-. Chiayi Yunlin Tainar. .~
years
,-_
-~
Numher
Countr fes
completed
l-
_ ~.~
11
Two clusters had been completed in each township and the mobile x-ray unit visited each one. Chiayi City and another 4 townships were excluded from the programme during this year.
23.7
126
1.l_iA N
TABLE III.-THE
NUMBER
OF SPUTUM-POSITIVE
CASES
DISCOVEREDBY THE
CASE-FINDING
PROGRAMME
IN
1971
a!;p1rtum-positive tubarculosi.> Counfy
Chiayi per 1000 registered Yunlin per 1000registered Tainan per 1000 registered Total per 1000 registered % of total positive
Total persons registered
Positive srneur by home-to-home collection 37
7,870
Positive smear 01 lar.yngeal swab culture after chest s-ray* 31
4.7
13,045
51
10,492
56
31,407
68
58
Li.3
4.4
5.3
104 9.Y
4.6 137
4.6 51
8.6 109
48
144
Total
3.9
3.9 ~--
-/-
281 4.4 49
90 100
*Of the 137, there were 86 with a positive smear and 51 positive only on laryngeal swab culture.
x-ray had been reported abnormal; thus 82% were found by smear examination. A further 5 l (18 %) had only a positive laryngeal swab culture. Those found on the initial sputum examination were also x-rayed. In 53 (37%) the disease was classed as far advanced and in 76 (53 %) moderately advanced (NTA classification); in only 15 (10%) was it minimal. On the other hand, among those positive only on laryngeal swab culture it was minima1 in 39%. Selectiw radiography During the year 36,465 people were x-rayed (including 1,636 below the age of 30) (Table IV). Those advised to be x-rayed were either aged 60 or more or younger than 60 but with respiratory symptoms. Of these, 2,461 (6.7 %) were reported to have lesions suggestive of tuberculosis. But the extent was minima1 in 62% of these; and laryngeal swab culture was positive in only 6%.
Discussion An effective case finding method is one of the most important factors in a tuberculosis control programme, especially in developing countries where prevalente is high and a notification system non-existent or incomplete. Selective miniature radiography - of persons with respiratory symptoms _ is an efficient method. It is the most productive and the cheapest. In a survey of methods in 1969 in Taiwan this method yielded 25.4 infectieus cases per 1000 examined at a tost of only US $12-4 per case. The main requirement for success is good organization. The people with symptoms must be brought together at the right time for the visit of the mobile x-ray unit. Mass sputum examination by house-to-house collection involves much work and is time consuming. However, even with relatively inexperienced personnel it can give a high yield. In this investigation 51 % of the bacteriologically confirmed cases were discovered by the first sputum collection and 63 % of those eventually found positive on smear examination. Thus the majority of infectieus people - those positive on smear examination - can be quickly discovered and promptly treated. Moreover, during house-to-house visiting people with respiratory symptoms but unable to produce a sputum specimen can be advised to be x-rayed, recorded and organized for the subsequent visit of the x-ray unit. With this new approach to case-finding, combining house-to-house sputum collection and selective radiography, during one year 41 ‘A of the 1240 villages in the Chiayi Region have been
CASE-FINDING TABLE
IN TAIWAN
127
IV.-RESULTS OF SELECTIVEMINIATURECHFST RADIOCRAPHY
IN 1971
Extent of’disease No. examined
__ less than 30
_-
Minima1 No. %
Moderately advanced No. 90
Far advanced No. ‘4
Pleura1 efision No. 7;
Total No.
1,636
37
14
8
60
30-59
16,803
533
210
91
835
60 or more
18.026
959
459
145
1,566
‘~(
3.7 5.0 s. 7
_Total
36,465
1,529
244
683
4.2
~~__
1.9
5
0.6
2,461 -
6.7
visited and 20,452 adults aged 30-59 years with respiratory symptoms registered. One hundred and forty-four people with smear positive tuberculosis have been discovered by lay tuberculosis workers using microscopy. Treatment was begun without delay. Another 137 sputum-positive cases and 2,322 ‘suspect’ cases radiographically have been detected through well-organized selective chest x-ray examination. The prevalente rates of both sputum-positive and ‘suspect’ cases are much higher than the rates for corresponding age groups in the 3rd prevalente survey carried out in Taiwan in 1967. This new approach to case-finding is productive and worthwhile trying in developing countries in which the tuberculosis problem is similar to that in Taiwan.
1 am greatly indebted to Drs. H. T. Lin and C. T. Hsing for their encouragement and suggestions for this study. My thanks are also to Dr. L. S. Hsu and Miss C. T. Chang and others of the staff of Chiayi Tuberculosis Centre for their help in preparing the report.
REFERENCES BAILY,G. V. J., SAVI~, D., GOTHI, G. D., NAIDU, V. B. & NAIR, S. S. (1967). Potential yield of pulmonary tuberculosis cases by direct microscopy of sputum in a district of South India. Bulletrn of the World Health Organization, 37, 875.
CHU, C. C. (1968). Comparison of tuberculosis case-finding methods. Chinese Medical Journal, 15. HSING, C. T. (1967). Chest microfilm versus direct microscopic sputum examination in tuberculosis control in the developing countries. Diseases of the Chest, 52,648. LUAN, H. W. (1972). Case-finding in Taiwan. Bulletin of the International Union against Tuherculosis, Supplt. No. 2. p. 137.
A NEW CASEFINDING
PROGRAMME
IN A REGION OF TAIWAN
By HSIAO-WENLUAN* from rhe Taiwan Provincial
Chiayi Tuberculosis
Cenfre, Chiayi,
Taiwan, R.O.C.
Smnmary
Sputum examination by house-to-house collection and chest radiography by a mobile unit of people with respiratory symptoms have been used in a new case-finding programme in Chiayi Region of Taiwan. Lay tuberculosis workers were employed to visit the houses, collect and examine sputum specimens and organize the radiography sessions. The mobile x-ray unit visited each area twice a year. During 1971, 512 villages were visited and 20,452 adults with respiratory symptoms registered. One hundred and forty-four persons with sputum positive on microscopy were discovered by the house-to-house sputum collection. A further 86 microscopy-positive were found by examining sputum from those with x-ray abnormalities and 51 positive only by laryngeal swab culture. Thus, 281 bacteriologically confirmed cases of pulmonary tuberculosis were found (9.0 per 1000 registered), 51 ‘A at the first home visit. The method allows both rapid identification of sources of infection in the community and later identification of bacteriologically positive cases among persons who were unable to provide sputum specimens initially. Of the total of 230 with sputum positive on microscopy, 63 % were found at the first home visit and chemotherapy could be started without delay. RESUMÉ L’examen des crachats après collecte de maison à maison et la radiographie pulmonaire par une unité mobile des sujets présentant des symptomes respiratoires ont été utilisés au tours dun nouveau programme de dépistage dans la region Chiayi de Taiwan. Des travailleurs auxiliaires de la lutte antituberculeuse ont été employés pour visiter les maisons, recuellir et examiner les échantillons de crachats et organiser les sessions de radiographies. L’unité radiographique mobile visitait chaque zone 2 fois par an. Au tours de 1971, 512 villages ont été visités et 20.452 adultes présentant des symptômes respiratoires, répertoriés. Cent quarante quatre sujets avec des crachats positifs à la microscopie ont été découverts par la collecte des crachats de maison à maison. Quatre vingt six examen positifs supplémentaires ont été trouvés par l’examen des crachats des sujets présentant des anomalies radiographiques et 51 ont été positifs seulement par culture après écouvillonage laryngé. Ainsi 281 cas de tuberculose pulmonaire bactériologiquement confirmées ont été trouvés (9,0 pour 1000 sujets répertoriés) dont 51% lors de la première visite à domicile. Cette methode permet à la fois une identification rapide des sources d’inffection dans la communauté, et plus tard l’identification des cas bactériologiquement positifs parmi les sujets qui étaient incapables de fournir d’emblée des crachats. Sur le total de 230 sujets avec des crachats positifs a l’examen microscopique, 63 % ont été dépistés à la première visite à domicile et la chimiothérapie a pu être commencée sans délai.
*presentaddress: Taiwan Provincial Tuberculosis Control Bureau, 10 Chingtoi Road West, Taipei, Taiwan, R.O.C. D
122 RESUMEN Para un nuevo programa de búsqueda de cases en Chiyai, Provincia de Taiwan, se emplearon exámenes de esputos en coleccidn a domicilie y radiografías de tórax con un equipo móvil en los individuos con síntomas respiratorios. Se emplearon trabajadores laicos para visitar las casas, recoger y examinar los esputos y organizar los exámenes radiográficos. Los equipos móviles radiográficos recorrieron cada area dos vetes por año. En 1971 fueron visitados 512 pueblos y se registraron 20452 adultos con síntomas respiratorios. Por medio de la colecta domicilaria de esputos se descubrieron 144 personas con baciloscopia positiva. Otros 86 cases fueron descubiertos al examinar los esputos de pacientes con alteraciones radiográficas; en 51 cases se halló positivo el cultivo del hisopado laringeo. En total, se hallaron 281 cases de tuberculosis con confirmación bacteriológica (9 por 1000 de los registrados), y el 51 x, en la primera visita domiciliaria. El método permite una rápida identificación de las fuentes de infección en la comunidad asi coma el descubrimiento ulterior de cases con baciloscopia positiva que no pudieron obtener esputos inicialmente. Del total de los 230 cases con baciloscopia directs positiva el 63 % fue descubierto en la primera visita domiciliaria y se pudo iniciar la quimioterapia de inmediato.
ZUSAMMENFASSUNG Im Rahmen einer Fallfindungsaktion in der Provinz Chiayi (Taiwan) wurden Sputumproben in der Wohnung eingesammelt, auflerdem Röntgenaufnahmen von Personen mit Beschwerden vonseiten der Atemwege durch eine mobile Röntgeneinheit angefertigt. Laienkräfte wurden eingesetzt, urn die einzelnen Haushalte aufzusuchen, das Sputum einzusammeln und die Röntgentermine zu organisieren. Die Schirmbildeinheit suchte jeden Bezirk zweimal im Jahre auf. 1971 wurden in 512 Dörfern 20 452 Erwachsene mit Symptomen seitens der Atemwege registriert. Einhundertvierundvierzig Fälle mit positivem Sputumausstrich wurden durch die Sputumaktion entdeckt. Weitere 86 positive Ausstriche gab es durch SputumuntersuchungdernTrägervonpathologischen Befunden im Röntgenbild, ebenso 51 positive Kulturen vom Kehlkopfabstrich. Insgesamt wurden 281 Fälle von bakteriologisch bestätigter Lungentuberkulose gefunden (9,0/1000 Registrierte), 51% davon durch den ersten Hausbesuch. Mit dieser Methode lassen sich sowohl die Infektionsquellen in der Bevölkerung schnell identifizieren als auch die bakteriologisch positiven Fälle unter den Personen herausfinden, die anfangs kein Sputum produzieren konnten. Von 230 Fällen mit positivem Sputumausstrich wurden 63yi durch den ersten Hausbesuch erfaBt; hier konnte die Behandlung ohne Verzögerung eingeleitet werden. Introduction During the past 22 years the three main measures for tuberculosis control in Taiwan have been BCG-vaccination, detection of previously unknown cases and chemotherapy. Because of the changing epidemiological, social and economie situation as wel1 as the availability of personnel, the tuberculosis control programme has had to be changed from time to time to meet the actual existing conditions. In the first 10 years case-finding was mainly by chest radiography of organized groups such as school-children, students, factory workers, government employees and military personnel. In the next 10 years the emphasis shifted to unorganized civilian groups, as it was considered that these would yield more tuberculosis cases. This is the so-called ‘community-wide case-finding
CASE-FINDING
IN
123
TAIWAN
programme’. Only during the past 2 years have sputum examinations in combination with selective chest radiography been developed. These 2 methods have their pros and cons (Baily and others, 1967; Hsing, 1967; Chu, 1968). They have been evaluated in Taiwan and reported at the VIIth Eastern Regional Conference of the International Union against Tuberculosis (Luan, 1972). In 1969 it was more costly to use miniature radiography on a community-wide basis (Table 1). To find one infectieus case tost NT $2,987 (US $74.4). By sputum examination without radiography it tost NT $1,415 (US $35.4). Selective radiography, examining only those with respiratory symptoms, was the least expensive - only NT $494 (US $12.4) for each infectieus case. To carry out selective radiography it is, of course, necessary to bring together al1 those in the community who have respiratory symptoms at the time when the mobile x-ray unit is due to arrive at the locality. The most dangerous sources of infection in the community are people with a positive sputum on microscopy; and these are mostly among the middle-aged and old. Such cases should be discovered without delay by sputum examination. But not al1 who cough can produce sputum at the time required; and some infectieus patients wil1 have a negative sputum at the first examination. Without too great an increase of tost, the two least expensive procedures - sputum examination and selective radiography - can be combined. This is the basis for the case-finding programme in Chiayi Region.
Chiayi Region Chiayi Tuberculosis Centre is located in Chiayi City in the South-centra1 part of Taiwan (Figure 1). It is responsible for a region consisting of 3 counties embracing 70 townships and has an area of 5245.8 sq km and a population of 2.5 million people. There is one health bureau in each county and one health station in each township. They are responsible for the total health programme in the community. Because Taiwan has not yet been wel1 industrialized, most people are stil1 living in the countryside TABLEIK---THEOPERATIONALCOST OF THREECASE-FINDINGPROGRAMMES IN TAIWAN IN 1969
Number of examinations Suspected tuberculosis - cases Infectieus tuberculosis - cases
Community-wide miniature radiography
Selective miniature radiography*
Sputum examination alone
13,149 497 48 3.6 per ICKNI
5,896 420 150 25.4 per 1000
16,901t 202 12.5 per 1000
Total tost Manpower CNT db)8
X-ray Sputum
72,775.0 26,625.0
37,395.0 11,155.o
280,800.O
Materials.
X-ray Sputum
40,917.o 3,079.o
19,679.O 5,896.O
5,070.o
10.9 228.7 2,987.4
12.6 135.9 494.2
16.9
~~~ Unit rost (NT I)
One examination One suspect case One infectieus case
1,415.2
*Radiography only for those with respiratory symptoms. tThe 16,901 specimens were from 16,154 persons (14,988 age 45 years or more and 1,166 age less than 45). &IONT $=l US b.
124
LUAIï
and most are working in agriculture. The population of a township The people live in 15 to 25 villages which are almost evenly scattered The health station is usually located in the largest village where the usually in the centra1 part of the township geographically, except portation is very convenient. Two hours by bicycle is the longest to the most remote village.
varies from 20,000 to 40,000. within the township boundary. township office is situated. It is in the mountain areas. Transdistance from a health station
The New Control Programme Tuberculosis control is fully integrated into the genera1 health service. Each health bureau has its own tuberculosis control work which is carried out by its regular staff. In order to increase the manpower for tuberculosis control in the peripheral health units, high school graduates have been recruited since 1966. They are trained for 3 weeks in the principles of control and the techniques of microscopic examination of sputum smears. They are assigned singly to selected health stations for case-finding work and also to help supervise domiciliary chemotherapy in the community.
Yangmingshan Admin. District
Keelung City
Chiayi Region: Area: 5245.82 Sq. Km Population: 2.5 Million (1970) County Health Bureaux: 3 Township Health Station: 70
b-!
/
_,[aitung C. ! / !7
FIG. 1 Map of Taiwan showing the Chiayi Region.
CASE-FINDING
IN
125
TAIWAN
Since 1971 the lay tuberculosis workers have been requested to carry out the new case-finding programme in their own community in the following four steps: 1. Find out the name, location and population of al1 villages in their township. 2. Group the villages into 3 to 6 clusters, the population size in each cluster being limited to 8,000 to 10,000. 3. Get census material from the census unit of the township office including name, age, sex and address of al1 inhabitants above 30 years. 4. Visit these people house-by-house and register those aged 30 to 59 with respiratory symptoms and al1 people 60 years and above. Collect sputum for direct microscopy if they can produce it. Give treatment to smear-positive cases promptly. Summon those people with respiratory symptoms but without sputum available, those whose sputum was negative by direct smear and all people above 60 for mass miniature chest x-ray examination on the day when the mobile unit is scheduled to come. They are asked to complete such case-finding activities for one cluster in the first six months, and the second in the next six months. The mobile x-ray unit is sent twice a year to each health station. It is hoped to complete one round of such screening in 2 to 3 years for each township. Results
Although Chiayi City is equivalent to a township within Chiayi County administratively, it is really a large city with a total population of 242,662. So it is excluded from this programme. Another two townships, Wufeng and Ta-pu, in Chiayi County are located in a mountain area; they were also excluded because of the difficult access for the mobile x-ray unit. Two townships in Tainan County failed to participate because no lay tuberculosis worker was available. Through the whole year of 1971, 65 townships actually participated in this programme. There were 2,337,994 people living in 1,240 villages in 3 counties in Chiayi region (Table 11). Five hundred and twelve (41.3 %) of 1,240 villages had had completed visits by lay tuberculosis workers in the year 1971. Out of 203,027 adults aged 30-59 years, 20,452 (10.1%) with respiratory symptoms had been registered, and out of 46,162 aged 60 years or more 10,995 (23.7%) had been registered. A total of 31,407 persons with symptoms were registered during the house-to-house visits. Two hundred and eighty-one people with a positive sputum were discovered (9.0 per 1000 registered) (Table 111). Examination of sputum smears collected at the visits by the lay workers discovered 144 cases (51%). Another 86 (31%) were discovered by sputum smear examination after the chest TARLEIT.-REGLWRATIONDURINGHOUSE-TO-HOUSE Vrsrrs BY LAY TUBERCULOSISWORKERSIN 1971
/!
Registration
_~
and visitation
Age 30-59 Population
Total
-.
of
597,196 801,842 938,956 2,337,994
in 1971
--
Age 60 and more years
No.
%
No.
% with symptoms
No.
% with symptoms
341 382 517
131 137 244
38.4 35.9 47.2
58,396 62,132 75,499
8.2 13.0 8.8
12,876 15,238 18,048
23.7 26.5 21.4
1,240
512
41.3
203,027
10.1
46,162
Villages
villages
-. Chiayi Yunlin Tainar. .~
years
,-_
-~
Numher
Countr fes
completed
l-
_ ~.~
11
Two clusters had been completed in each township and the mobile x-ray unit visited each one. Chiayi City and another 4 townships were excluded from the programme during this year.
23.7
126
1.l_iA N
TABLE III.-THE
NUMBER
OF SPUTUM-POSITIVE
CASES
DISCOVEREDBY THE
CASE-FINDING
PROGRAMME
IN
1971
a!;p1rtum-positive tubarculosi.> Counfy
Chiayi per 1000 registered Yunlin per 1000registered Tainan per 1000 registered Total per 1000 registered % of total positive
Total persons registered
Positive srneur by home-to-home collection 37
7,870
Positive smear 01 lar.yngeal swab culture after chest s-ray* 31
4.7
13,045
51
10,492
56
31,407
68
58
Li.3
4.4
5.3
104 9.Y
4.6 137
4.6 51
8.6 109
48
144
Total
3.9
3.9 ~--
-/-
281 4.4 49
90 100
*Of the 137, there were 86 with a positive smear and 51 positive only on laryngeal swab culture.
x-ray had been reported abnormal; thus 82% were found by smear examination. A further 5 l (18 %) had only a positive laryngeal swab culture. Those found on the initial sputum examination were also x-rayed. In 53 (37%) the disease was classed as far advanced and in 76 (53 %) moderately advanced (NTA classification); in only 15 (10%) was it minimal. On the other hand, among those positive only on laryngeal swab culture it was minima1 in 39%. Selectiw radiography During the year 36,465 people were x-rayed (including 1,636 below the age of 30) (Table IV). Those advised to be x-rayed were either aged 60 or more or younger than 60 but with respiratory symptoms. Of these, 2,461 (6.7 %) were reported to have lesions suggestive of tuberculosis. But the extent was minima1 in 62% of these; and laryngeal swab culture was positive in only 6%.
Discussion An effective case finding method is one of the most important factors in a tuberculosis control programme, especially in developing countries where prevalente is high and a notification system non-existent or incomplete. Selective miniature radiography - of persons with respiratory symptoms _ is an efficient method. It is the most productive and the cheapest. In a survey of methods in 1969 in Taiwan this method yielded 25.4 infectieus cases per 1000 examined at a tost of only US $12-4 per case. The main requirement for success is good organization. The people with symptoms must be brought together at the right time for the visit of the mobile x-ray unit. Mass sputum examination by house-to-house collection involves much work and is time consuming. However, even with relatively inexperienced personnel it can give a high yield. In this investigation 51 % of the bacteriologically confirmed cases were discovered by the first sputum collection and 63 % of those eventually found positive on smear examination. Thus the majority of infectieus people - those positive on smear examination - can be quickly discovered and promptly treated. Moreover, during house-to-house visiting people with respiratory symptoms but unable to produce a sputum specimen can be advised to be x-rayed, recorded and organized for the subsequent visit of the x-ray unit. With this new approach to case-finding, combining house-to-house sputum collection and selective radiography, during one year 41 ‘A of the 1240 villages in the Chiayi Region have been
CASE-FINDING TABLE
IN TAIWAN
127
IV.-RESULTS OF SELECTIVEMINIATURECHFST RADIOCRAPHY
IN 1971
Extent of’disease No. examined
__ less than 30
_-
Minima1 No. %
Moderately advanced No. 90
Far advanced No. ‘4
Pleura1 efision No. 7;
Total No.
1,636
37
14
8
60
30-59
16,803
533
210
91
835
60 or more
18.026
959
459
145
1,566
‘~(
3.7 5.0 s. 7
_Total
36,465
1,529
244
683
4.2
~~__
1.9
5
0.6
2,461 -
6.7
visited and 20,452 adults aged 30-59 years with respiratory symptoms registered. One hundred and forty-four people with smear positive tuberculosis have been discovered by lay tuberculosis workers using microscopy. Treatment was begun without delay. Another 137 sputum-positive cases and 2,322 ‘suspect’ cases radiographically have been detected through well-organized selective chest x-ray examination. The prevalente rates of both sputum-positive and ‘suspect’ cases are much higher than the rates for corresponding age groups in the 3rd prevalente survey carried out in Taiwan in 1967. This new approach to case-finding is productive and worthwhile trying in developing countries in which the tuberculosis problem is similar to that in Taiwan.
1 am greatly indebted to Drs. H. T. Lin and C. T. Hsing for their encouragement and suggestions for this study. My thanks are also to Dr. L. S. Hsu and Miss C. T. Chang and others of the staff of Chiayi Tuberculosis Centre for their help in preparing the report.
REFERENCES BAILY,G. V. J., SAVI~, D., GOTHI, G. D., NAIDU, V. B. & NAIR, S. S. (1967). Potential yield of pulmonary tuberculosis cases by direct microscopy of sputum in a district of South India. Bulletrn of the World Health Organization, 37, 875.
CHU, C. C. (1968). Comparison of tuberculosis case-finding methods. Chinese Medical Journal, 15. HSING, C. T. (1967). Chest microfilm versus direct microscopic sputum examination in tuberculosis control in the developing countries. Diseases of the Chest, 52,648. LUAN, H. W. (1972). Case-finding in Taiwan. Bulletin of the International Union against Tuherculosis, Supplt. No. 2. p. 137.