Epidemiological Studies on Ascaris lumbricoides Reinfection in Rural Communities in Korea II. Age-specific Reinfection Rates and Familial Aggregation of the Reinfected Cases

한국 농촌지역의 회충재감염에 대한 역학적 조사연구 ll. 연령별 재감염률 및 재감염의 가족집적성

  • 채종일 (서울대학교 의료대학 기생충학교실 및 풍토병연구소) ;
  • 서병양이순형조승열 (서울대학교 의료대학 기생충학교실 및 풍토병연구소 중앙대학교 의과대학 기생충학교실)
  • Published : 1983.06.01

Abstract

Epidemiological studies on the reinfetion pattern of Ascaris lumbricoides were undertaken by means of blanket mass chemotherapy and worm collection in a rural village in Korea, during 1977~1980. The study objectives were to determine the age (sex)-specific reinfection rate during 2, 4, 6 and 12 months through repeated mass chemotherapy with pyrantel pamoate, and to observe the familial aggregation tendency of the reinfected cases. The results obtained are as follows: 1. The age (sex)-reinfection curve revealed that the reinfection rate is much higher in younger individuals than in olders in all of 4 kinds of interval chemotherapy groups. The highest reinfection rate and the highest burden of reinfected worms were observed in preschool children, followed by primary school students. Such fluctuation in the age-specific reinfection rates was more pronounced in males than in females. 2. There was noted a significant tendency of familial aggregation among the reinfected cases. It is suggested that reinfection occurs never randomly but preferably to the members of certain household families. From these reinfection analyses, it is inferred that the principal mode of A. lumbricoides transmiSSIOn in the surveyed rural area is likely to be of 'dooryard type', in which case children and certain family members are more preferably reinfected. It is also suggested that the preschool children should be included in the primary targets of mass control programme.

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