[Epidemiological studies of Clonorchis sinensis prevailed in the peoples of Kyungpook Province]

Abstract

The author studied the infection rates of Clonorchiis sinensis in the inhabitants of Kyungpook Province, and surveyed infestation rates of Clonorchis metacercarias in the twelve kinds of fresh water fishes for the purpose of the eradication. plan of clonorchiasis of Kyungpook Province. The examination was continued from April 1960 to October 1962 with 24,252 inhabitants ranging from four months to over sixty aged. All the family were tested intradermally with Clonorchis antigen and then confirmed the eggs by M.G.L. technique. The results of the examination were summarized as follows. I. The infection rate of the inhabitants; 1) In the people tested, 27.7 per cent was infected with Clonorchis sinensis. 2) There were no remarkable differences in the infection rates among each Districts; River side inhabitants(Yungchun-Gun 23.6 percent, Andong-Gun 27.4 %), paddy field inhabitants(Yungchun-Gun 23.6 %, Sangchu-Gun 29.1 %) and mountain side inhabitants (Chungsong-Gun 23.8 %, Yungyang-Gun 27.7%). However, the infection rates of the river side peoples were slightly higher than that of the districts far from the river. 3) The infection rate of the male was 34.98 percent (4,628 out of 12,230), while the female was 18.96 per cent (2,090 out of 11,022). 4) The maximum infection rate of the male group was observed in the 35-39 age group (73.8 %) and in female, 55-59 age group (34.l percent) respectively, however it was gradually decreased in the senile group. II. The infection rates of the family group; 1) Those infected in both husband and wife were 28 percent(357 out of 1,289), husband only was 52 percent (672 out of 1,289) and wife only was 4 percent (50 out of 1,289). 2) The children of the infected parents revealed higher morbidity than that of the non-infected parents. 3) The children of the infected father revealed much morbidity than that of the mother's side. On the contrary, children's morbidity rate of the infected widow was higher than that of the widower. III. The infestation rates of fresh water fishes; 1) The metacercaria of Clonorchis sinensis was found in the flesh exclusive of the Misgurnus anguillicaudatus and Zacco platypus in the 11 kinds of fresh water fishes. 2) The maximum infestation rate of 55.8 percent was revealed at Pseudorasbora parva and next to it was Sarcocheilichthys wakiyae of 5l.7 percent. 3) The number of metacercaria in flesh was decreased as compared to the previously examined level.