Although it is technically superior to direct microscopy, expansion of culture
examination as a diagnostic and/or monitoring service depends largely on its
practicability in various phases of a national tuberculosis(TB) programme. Greater
emphasis on cultural examination will mean simplification of technical procedures and
usage of less expensive materials. In this regard several culture methods have been
compared on the basis of positive-case yield, technical procedure, and expense.
Specimens for this study were collected from 3,652 radiographic suspects found during
the 3rd national prevalence survey which was conducted in 1975. Both the laryngeal
swab and spot sputum collection methods were utilized. Examination of this group by
both direct microscopy and by the oxalic acid (OA) culture method yielder 198, or 5.4%,
bacteriologically positive cases. Of these, 93, or 2.5%, and 115, or 3.1%, were discovered
by direct microscopy from laryngeal swabs and spot sputa, respectively, while 134 cases,
representing 3.6% , and 138, or 3.8%, positive cases were discovered subsequently via
culture examination. The figures, of course, indicate reason to favor spot sputum
collection over the laryngeal swab within the peripheral laboratory where facilities are
unsuited for culture examination. In addition to these, findings comparing the results of
the culture examination utilizing three relatively simple culture methods, the OA method,
the Ogawa method, and the KIT(Korean Institute of Tuberculosis) method, also
tablulated. Although statistically insignificant, they showed definitively that the OA
method, which has been recommended by World Health Organization, produced fewer
positive-case results, (130, or 5.0%), than those discoveries of either the Ogawa, which
produced 140, or 5.4%, or the KIT method, which presented 145 cases or 5.6%.
Examination of the 729 spot sputa following the OA method, the simple Ogawa and
the KIT methods further substanciated, through demonstration, the superiority of either
the simple Ogawa or the KIT methods over any other, not only in positive-case yield
capabilities, but in cost analysis as well. The results showed that the OA method
produced 91 or 12.5% cases could be found overall, while 105 cases or 14.4% and 107
cases or 14.7% became available employing the Ogawa and the KIT methods,
respectively. Furthermore, when the concentrated specimens were inoculated on L-J,
Ogawa, and KIT media, 105(14,4%), 106(14.5%), and 120(16.5%) positive cases were
found, respectively. Direct inoculation of spot sputum specimens with penicillin into the
peritoneal cavity of mice produced a marked decrease in positives, 38, or 7.6%, than the
findings given by the direct microscopic or culture examination methods, which was 118
cases, representing 23.6%.
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