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Detection of pulmonary tuberculosis by sputum survey
Tubercle, Lond., ( ! 9*iO), 41, 363
Detection of Pulmonary Tuberculosis by Sputum Survey By LIONEl., I".RIN
from the Chest Clinic, Mertlo,r Tydfil, Glamorgan Although mass radiography is playing and will continue to play an impewtant role in tuberculosis case finding, the yield per n u m b e r examined is decreasing and the: cost pet" case discovered increasing. Furthermore, with present facilities, only a small proportion of tim general population of each clinic area can be examined, even at infi-equent intervals. It seemed, therefore, desirable to investigate the ctlicacy and cost of sputum testing as an additional technique which might be used I~y clinics to supplement tlm effect of mass radiography. Method
A section of M o u n t a i n Asia, (population 26,128) a mining town ira the Abe,'dare Valley, Glamorgan, was chosen for the investigation. In 1958 there were eighteen notifications of pulmonary tuberculosis, nine of which were confirmed bacteriologically; and the proportion of children tuberculin positive at the age of thirteen years was 12 ~,,, suggesting a low incidence of inti:ction. A circular letter, signed by the chest physician and thc ,Xlcdical Ofticer of Health, appealing for" co-operation, was distributed by a retired nurse working part-time. A week later, the nurse called and distributed sputum bottles to those who said they had sputum. T h e nurse also distributed more letter's to adjoining houses and collected ~he sputum bottles next day. T h e sputum bottles were then posted to the lalmratory. In all, 1,395 houses were visited, and 910 householders agreed to co-operate. From l~r. 3,138 adults in the households, 2,001 sent specimens of sputum and 1,982 of tl~,'s~' were" successfully cultured (19 were contaminated). Results
Bacteriology O f the 1,982 specimens, tbur were found to be positive fi~r tubercle bacilli. 1",;/,, of the cultures were contaminated. No microscopical examination was made. "l'hc specimens were cultured by the method of Marks and T h o m a s (1958). No atypical acid-fast bacilli were found. About half tile specimens were of poor quality, with a v o l u m e o f less than 1 ml. and o f fluid consistency.
"
All the four cases found were men, aged 37, 61, 63 and 73. All had shadows ira their x-rays compatible with the diagnosis of a tuberculous lesion. It is interesting to note that all had uncavitat,:d streaky or nodular lesions which were not extensive. Ira all cases the positive cultural result was later confirmed. None of the patients had sought medical advice and all were mixing freely with the rest of the community.
Comparison with mass radiography The response:~Table I shows a comparison in the response to the sputum survey and to mass radiography surveys carried out ira Wales in 1958, which include factory surveys and other specialised groups. T h e sputum survey response would aptxrar to have been more successfial ira the older and less successfid in the younger age groups.
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'rABI.E ] I. ~ COST PER .~PIYl'UM POSt r i v e CASl.. ]:Ol'Nl~ tX XIARIOIJS SI;R'r
I Vdsh Cost Nctt
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17eld o f C a s e s : ~ T h e \Veish Mass Radiography Service in 1958 discovered !.8 cases of tuberculosis (sputum positive and negative) per 1,000 examined. In the l-lolvhead survey ( J a r m a n and others, 1959) 1 in 4 of the cases were sputuna positive, but this ratio probably varies considerably ira different surveys. It does, however, suggest that the yield of sputum positive cases per total numl;er examined was higher in: the sputum survey (2 per 1000) than jn the mass radiography work. On tile other hand, a sputum survey must be considered less 'sensitive' as the sputuna negtive caases arc missed as well as other radiographic abnormalities. This point has been investigated for us by the Welsh Mass Radiography Service, who attempted to x-ray tile population whose sputum we had examined after completion of the sputunl survey. T h e y succeeded in x-raying 714 of" the sputum negative pspulation and found two sputum negative cases. Cost: .... The cost can be considered in two ways: the nett cost, which is the actual expenditure incurred; and the gross cost, whicl:t includes a share of overheads and of the salaries of the perrnanent stair. Table I1 gives a conaparison betwcen tim Sl3UtUm survey, the Gl.asgow mass radiography survey (Glasgow Corporation, 1958) and routine ~,'Velsh mass radiography for" 1958. The cost for the sputum survey per positive sputum case discovercd is obviously very much lower, but it must be remembered that on this small scale it was completed without requiring additional laboratory facilities. I f new laboratory facilities were required, tile gross cost would be vcr.v much greater. Discussion
"I'he two sputum surveys most comparable with our own are tile World Health Organization survey in Nairobi ( W . H . O ] U N I C E F Assisted Tuberculosis l'roject, 1959) and the bronchitis survey of Post Office workers in London (l~lmes, 1)uttora and Fletcher, 1959). I n the Nairobi survey, covering a 19o' sarnple of tile p(,pulation there, four specimens out of the 822 examined showed acid-fhst bacilli; /)ut as all four grew at room temperature tile)' were not considered to be AO'co. tuberculosis. In the bronchitis survey in London, one positive s p u t u t n w a s found amongst 14-t-mett and 144 women, most of whom w e r e asked to produce sputum on three occasions. T h e n u m b e r of specimens examined was 238. It seems therefi)re reasonal)le to summarise tim present position of sputum surveys by claiming that as a mzLss stlrvey instrument its value is promising but still unproven. \{re hope to improve tim technique by, for instance, substituting 'collection' specimens for the present 'spot' spccimens (Andrews and Radhakrishna, 1959) and reducing the refusal rate by more intensive home visiting. O n the other hand, there does seem good evidence that it would be an effective technique for sura,eys on selected groups. Thus the sputum survey may be of value in a suspected high incidence locality where the normal visit of the mass radiography unit is not due for some considerable time. It may also help to render
366
"ru n v. Re. t.v.
a total community x-ray survey attempt more comprehensive by attempting to sputum lest the small proportion of non-attenders. The main disadvantage of the sputum survey is its inability to discover other radiographic abnormalities; so it could be particularly usefully employed on groups where the x-~'ay findings are known. One s~lch group are miners suffering from progressive massive fibrosis. Once the radiographic diagnosis has been made, little fi~rther is gained therapeutically I~y repeating x-rays. On the other hand, the tinding of tuberch: bacilli leads to effective therapeutm action. The expected yield in such cases is between 1 and 2 ~,,~(Carpenter and others, 1956). Another similar group are the quiescent and arrested tuberculous patients. For instance, Paviere (1956) found fourteen positive sputa amongst 82 factory workers who had returned to work classified as ~arrested'. T h e third rather similar group are those where it is impossible for some reason to take an x-ray. Examples of this are the people in a community survey who, for physical reasons, are unable to attend the centre. Other possible groups could be communities in under-developed areas where it is impossible to transport x-ray apparatus. The survey response showed a much better response to the older aT.e groups. A trial of sputum surveys amongst pensioners in the homes for the aged seems likely, therefore, to produce a high yield and to effect a higher ct~verage than an x-ray survey. Summary
A sputum testing scheme for the detection of infectious tuberculosis is described. Approximately 2 sputum positive cases were found per 1,000 persons examined, at a net cost of s (s gross) per patient diagnosed. Suggestions are made as to how the technique could be imlzroved and the populations to which it could be most usel'ully applied. 1 am gratefid to Profi:ssors A. I.. Cochrane and 1". R. G. Heaf and Dr. T. Francis.]arman for much advice and criticism, and l)r..]. Marks of th(: Tt,berculosis Rcfi:rencc lmlmrator.v, Cardiff: who was res.'po,MIjle fi~r the Imct:'riologlcal investigations. Rcl'cl'CllCe$
Andrews, R. I.!., and Radhakrishna, S. (1959) Tubercle, Lond., 40, 155. C:arpcnter, R. G., Gochranu, A. 1.., Miall, W. E., Jarman, T. F., and Hockaday, G. (1956) Tubercle, ldmd., 37,225. l'~hnc's', P. C., l)utton, A. A. C., and Fletcher. (3. M. (1959) l.~mcel, i, 12'tl. C;la.sgow Corporation. (1958) Glasgow's X-Ray Campaign against Tubr Glasgow Corporal ion Printing and Stationery Department. .Jarman. T. F.. C,~rrado M.A., Wynne Griflhhs G. and .]ones J. G. (1959) Annual Rcp~Jrt, County Medical Officer fi~r Anglesey. Marks,.].. and "['homas, (_:. H. l-i. (1958) Alon. BuU. Aliniat. lilthLab. Serv., 17, 19,1. Paviere, H. D. (1956) Rthabilitation, aV.S., No. 18, p. 7. W.H.O.IUNICEF Assisted Tuberculosis Project. (1959) Tuberculosis Survey of Nairobi 1958-1959, 9"Fypc~cript, June, 1959.
Detection of Pulmonary Tuberculosis by Sputum Survey By LIONEl., I".RIN
from the Chest Clinic, Mertlo,r Tydfil, Glamorgan Although mass radiography is playing and will continue to play an impewtant role in tuberculosis case finding, the yield per n u m b e r examined is decreasing and the: cost pet" case discovered increasing. Furthermore, with present facilities, only a small proportion of tim general population of each clinic area can be examined, even at infi-equent intervals. It seemed, therefore, desirable to investigate the ctlicacy and cost of sputum testing as an additional technique which might be used I~y clinics to supplement tlm effect of mass radiography. Method
A section of M o u n t a i n Asia, (population 26,128) a mining town ira the Abe,'dare Valley, Glamorgan, was chosen for the investigation. In 1958 there were eighteen notifications of pulmonary tuberculosis, nine of which were confirmed bacteriologically; and the proportion of children tuberculin positive at the age of thirteen years was 12 ~,,, suggesting a low incidence of inti:ction. A circular letter, signed by the chest physician and thc ,Xlcdical Ofticer of Health, appealing for" co-operation, was distributed by a retired nurse working part-time. A week later, the nurse called and distributed sputum bottles to those who said they had sputum. T h e nurse also distributed more letter's to adjoining houses and collected ~he sputum bottles next day. T h e sputum bottles were then posted to the lalmratory. In all, 1,395 houses were visited, and 910 householders agreed to co-operate. From l~r. 3,138 adults in the households, 2,001 sent specimens of sputum and 1,982 of tl~,'s~' were" successfully cultured (19 were contaminated). Results
Bacteriology O f the 1,982 specimens, tbur were found to be positive fi~r tubercle bacilli. 1",;/,, of the cultures were contaminated. No microscopical examination was made. "l'hc specimens were cultured by the method of Marks and T h o m a s (1958). No atypical acid-fast bacilli were found. About half tile specimens were of poor quality, with a v o l u m e o f less than 1 ml. and o f fluid consistency.
"
All the four cases found were men, aged 37, 61, 63 and 73. All had shadows ira their x-rays compatible with the diagnosis of a tuberculous lesion. It is interesting to note that all had uncavitat,:d streaky or nodular lesions which were not extensive. Ira all cases the positive cultural result was later confirmed. None of the patients had sought medical advice and all were mixing freely with the rest of the community.
Comparison with mass radiography The response:~Table I shows a comparison in the response to the sputum survey and to mass radiography surveys carried out ira Wales in 1958, which include factory surveys and other specialised groups. T h e sputum survey response would aptxrar to have been more successfial ira the older and less successfid in the younger age groups.
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3(]5
'rABI.E ] I. ~ COST PER .~PIYl'UM POSt r i v e CASl.. ]:Ol'Nl~ tX XIARIOIJS SI;R'r
I Vdsh Cost Nctt
Gross
lqesenl "survey
s
Gla.tgow
,II.,~I.R.
.~ltrt'~)'
[ 195e )
(1957) s
,, i
s 100
s
s
17eld o f C a s e s : ~ T h e \Veish Mass Radiography Service in 1958 discovered !.8 cases of tuberculosis (sputum positive and negative) per 1,000 examined. In the l-lolvhead survey ( J a r m a n and others, 1959) 1 in 4 of the cases were sputuna positive, but this ratio probably varies considerably ira different surveys. It does, however, suggest that the yield of sputum positive cases per total numl;er examined was higher in: the sputum survey (2 per 1000) than jn the mass radiography work. On tile other hand, a sputum survey must be considered less 'sensitive' as the sputuna negtive caases arc missed as well as other radiographic abnormalities. This point has been investigated for us by the Welsh Mass Radiography Service, who attempted to x-ray tile population whose sputum we had examined after completion of the sputunl survey. T h e y succeeded in x-raying 714 of" the sputum negative pspulation and found two sputum negative cases. Cost: .... The cost can be considered in two ways: the nett cost, which is the actual expenditure incurred; and the gross cost, whicl:t includes a share of overheads and of the salaries of the perrnanent stair. Table I1 gives a conaparison betwcen tim Sl3UtUm survey, the Gl.asgow mass radiography survey (Glasgow Corporation, 1958) and routine ~,'Velsh mass radiography for" 1958. The cost for the sputum survey per positive sputum case discovercd is obviously very much lower, but it must be remembered that on this small scale it was completed without requiring additional laboratory facilities. I f new laboratory facilities were required, tile gross cost would be vcr.v much greater. Discussion
"I'he two sputum surveys most comparable with our own are tile World Health Organization survey in Nairobi ( W . H . O ] U N I C E F Assisted Tuberculosis l'roject, 1959) and the bronchitis survey of Post Office workers in London (l~lmes, 1)uttora and Fletcher, 1959). I n the Nairobi survey, covering a 19o' sarnple of tile p(,pulation there, four specimens out of the 822 examined showed acid-fhst bacilli; /)ut as all four grew at room temperature tile)' were not considered to be AO'co. tuberculosis. In the bronchitis survey in London, one positive s p u t u t n w a s found amongst 14-t-mett and 144 women, most of whom w e r e asked to produce sputum on three occasions. T h e n u m b e r of specimens examined was 238. It seems therefi)re reasonal)le to summarise tim present position of sputum surveys by claiming that as a mzLss stlrvey instrument its value is promising but still unproven. \{re hope to improve tim technique by, for instance, substituting 'collection' specimens for the present 'spot' spccimens (Andrews and Radhakrishna, 1959) and reducing the refusal rate by more intensive home visiting. O n the other hand, there does seem good evidence that it would be an effective technique for sura,eys on selected groups. Thus the sputum survey may be of value in a suspected high incidence locality where the normal visit of the mass radiography unit is not due for some considerable time. It may also help to render
366
"ru n v. Re. t.v.
a total community x-ray survey attempt more comprehensive by attempting to sputum lest the small proportion of non-attenders. The main disadvantage of the sputum survey is its inability to discover other radiographic abnormalities; so it could be particularly usefully employed on groups where the x-~'ay findings are known. One s~lch group are miners suffering from progressive massive fibrosis. Once the radiographic diagnosis has been made, little fi~rther is gained therapeutically I~y repeating x-rays. On the other hand, the tinding of tuberch: bacilli leads to effective therapeutm action. The expected yield in such cases is between 1 and 2 ~,,~(Carpenter and others, 1956). Another similar group are the quiescent and arrested tuberculous patients. For instance, Paviere (1956) found fourteen positive sputa amongst 82 factory workers who had returned to work classified as ~arrested'. T h e third rather similar group are those where it is impossible for some reason to take an x-ray. Examples of this are the people in a community survey who, for physical reasons, are unable to attend the centre. Other possible groups could be communities in under-developed areas where it is impossible to transport x-ray apparatus. The survey response showed a much better response to the older aT.e groups. A trial of sputum surveys amongst pensioners in the homes for the aged seems likely, therefore, to produce a high yield and to effect a higher ct~verage than an x-ray survey. Summary
A sputum testing scheme for the detection of infectious tuberculosis is described. Approximately 2 sputum positive cases were found per 1,000 persons examined, at a net cost of s (s gross) per patient diagnosed. Suggestions are made as to how the technique could be imlzroved and the populations to which it could be most usel'ully applied. 1 am gratefid to Profi:ssors A. I.. Cochrane and 1". R. G. Heaf and Dr. T. Francis.]arman for much advice and criticism, and l)r..]. Marks of th(: Tt,berculosis Rcfi:rencc lmlmrator.v, Cardiff: who was res.'po,MIjle fi~r the Imct:'riologlcal investigations. Rcl'cl'CllCe$
Andrews, R. I.!., and Radhakrishna, S. (1959) Tubercle, Lond., 40, 155. C:arpcnter, R. G., Gochranu, A. 1.., Miall, W. E., Jarman, T. F., and Hockaday, G. (1956) Tubercle, ldmd., 37,225. l'~hnc's', P. C., l)utton, A. A. C., and Fletcher. (3. M. (1959) l.~mcel, i, 12'tl. C;la.sgow Corporation. (1958) Glasgow's X-Ray Campaign against Tubr Glasgow Corporal ion Printing and Stationery Department. .Jarman. T. F.. C,~rrado M.A., Wynne Griflhhs G. and .]ones J. G. (1959) Annual Rcp~Jrt, County Medical Officer fi~r Anglesey. Marks,.].. and "['homas, (_:. H. l-i. (1958) Alon. BuU. Aliniat. lilthLab. Serv., 17, 19,1. Paviere, H. D. (1956) Rthabilitation, aV.S., No. 18, p. 7. W.H.O.IUNICEF Assisted Tuberculosis Project. (1959) Tuberculosis Survey of Nairobi 1958-1959, 9"Fypc~cript, June, 1959.