Prevalence, worm burden and other epidemiological parameters of <i>Ascaris lumbricoides</i> infection in rural communities in Korea

, Chai, Jong Yil; , Kim, Koo Soo; , Hong, Sung Tae; , Lee, Soon Hyung; , Seo, Byong Seol

doi:1985.23.2.241

Korean J Parasito > Volume 23(2):1985 > Article

Original Article


Korean J Parasitol. 1985 Dec;23(2):241-246. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1985.23.2.241
Copyright © 1985 by The Korean Society for Parasitology


Prevalence, worm burden and other epidemiological parameters of Ascaris lumbricoides infection in rural communities in Korea
Jong Yil Chai,Koo Soo Kim,Sung Tae Hong,Soon Hyung Lee and Byong Seol Seo
Department of Parasitology and Institute of Endemic Diseases, College of Medicine, Seoul National University, Seoul 110, Korea.


Abstract
The epidemiological status of ascariasis was analyzed in 8 rural villages in Korea, through observation of its epidemiological parameters such as prevalence, worm burden and basic reproductive rate. Total 978 inhabitants were subjected to stool examination and recovery of worms after chemotherapy with pyrantel pamoate. The results were as follows: The worm positive rate in each village was 16.5-79.5%, while the egg positive rate was 9-18% lower, 3.3-66.7%. The average worm burden(among all inhabitants) ranged from 0.21 to 8.44 by villages and the frequency of cases with each worm burden showed negative binomial distributions with 'k' values of 0.38-0.54. The prevalence rates (worm) in each village was almost identical with the theoretical ones from Anderson and May's equation; p=1-(1+M()/k)(-k), where 'p' is worm prevalence and 'M()' equilibrium average worm burden. The basic reproductive rate 'R' was calculated from 1.03 to 2.11. It is suggested that, although 'R' in lower endemic areas is approaching to the breakpoint of reinfection (R=1), control programs of ascariasis in Korea should be continued until it becomes below the level nationwidely.

Tables


	Table 1 Studied areas and epidemiological indices for Ascaris lumbricoides infection


	Table 2 Distribution of cases by worm burdens in each area


	Table 3 Negative binomial^* indices for the distribution of individual worm burdens of A. Lumbricoides


	Table 4 Theoretical prevalence (worm) and basic reproductive rate (R) according to Anderson et May (1982)'s model

References


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