Abstract

This study was undertaken to observe the fluctuation pattern of E.P.G. (eggs per gram of feces) according to the number of infected worms and developmental status of Ascaris lumbricoides. The cases were selected from 2,109 inhabitants of Hwasung Gun, Kyunggi Do, Korea, who had received pyrantel treatment in dose of 10 mg/kg during April 1977-May 1980 and who were cooperative enough to collect whole-day stool specimens for 2 days. Among them, 602 cases who had been infected with 1-5 worms were subjected to analysis. Egg examination was undertaken by means of cellophane thick smear technique and the amount of produced eggs was checked by Stoll's egg counting technique. The Ascaris worms were collected from stool specimens, counted in number in each case, and each worm was measured by length. The results could be summarized as follows: According to the increase of worm burden per case from l to 5, the egg detection rate increased from 33.4 percent to 95.7 percent. And the same pattern was observed when the only burden was considered. There were ample variations in the individual E.P.G. counts even among the cases with same burden, although the mean E.P.G. counts among the cases were quite proportionately increased from 842 to 3,467 according to the number of female worms, 1-4. However, from the distribution pattern of the number of each grade of E.P.G. count, it was revealed that the lower the number of females the more cases were with low grade of E.P.G. It was observed that the eggs could be detected after the female worm grew longer than 12.6 cm and the amount of eggs increased until the worm became about 25.0 cm, where a plateau was made in E.P.G. 1,300-1,400, and decreased significantly after 27.5 cm. And yet, wide variations in E.P.G. counts were noted even among the worms of similar growth. Accordingly, the E.P.G. value had better be used as a useful index to estimate the intensity of Ascaris infection and to compare the intensity between two communities, rather than be used to estimate the individual worm burden.