Detecting eggs from feces and/or sputum is probably closely associated with many factors such as degree or intensity of infection, physiological status of the host(age, eating habit and duration of residence in the area), the duration of infection for the parasite (age and reproductive activity of flukes), and methods of collecting specimens and technique of examination. Neverthless, it is difficult to determine which factor plays the most inportant role in detecting eggs except comparison of factual result obtained by standardized techniques. The purpose of the study was to find out which method would give better result for detection of eggs, and to estimate what proportion of patients would be missed when the method selected is used.

On a single examination of both specimens, stool and sputum, collected from the same person, sputum examination was found to be superior to stool examination for detection of eggs; 37 of 40 egg positives had eggs in sputum whereas only 21 of 40 in stool.

Repeated sputum examination on the same subject in spaced time gave higher overall egg detection rate; in the first examination for all skin reaction positives, the detection rate was 36.8%, in the second examination on those who had negative results in the first examination, it was 11.6% among 602 persons examined, and 5.3 percent of 95 persons who were negative in previous two examinations.

Thus, repeated sputum examinations (three times) increased the overall detection rate to 48.5% from 36.8%. According to the result obtained through this study, it would be worthwhile to recommend repeated sputum examinations at least three times on the same subject even if collecting second and third sputum is quite difficult problem in mass survey; about 12% of total patients who can be detected as positive by three times repeated examinations shall be missed if only a single sputum examination is done.