title: Prevalence of Clonorchis sinensis Infections Along the Five Major Rivers in Republic of Korea, 2007.
abstract: OBJECTIVE
  The prevalence of Clonorchis sinensis infection was investigated among residents of the five major river basins, that is, Hangang, Nakdonggang, Seomjingang, Yeongsangang, and Geumgang River basins in Korea.
  
  
  METHODS
  From January to December 2007, a total of 31,268 stool samples were collected from 29 localities and examined by the formalin-ether sedimentation technique.
  
  
  RESULTS
  Intestinal parasite eggs and/or protozoan cysts were detected from 2957 (9.5%) inhabitants. Number of residents harbouring helminth eggs in the faeces was 2542 (8.1%) for C. sinensis, 255 (0.8%) for Heterophyes spp., 36 (0.1%) for Echinostoma spp., 30 (0.1%) for Trichuris trichiura, 8 (0.03%) for Ascaris lumbricoides, 7 (0.02%) for Gymnophalloide seoi, and 50 (0.02%) for Trichostrongylus orientalis. Number of residents harbouring protozoan cysts in the faeces was 133 (1.3%) for Entamoeba spp. and 50 (0.2%) for Giardia lamblia. The positive rates of C. sinensis in Nakdonggang, Seomjingang, Yeongsangang, Geumgang, and Hangang River basins were 12.2%, 9.5%, 3.3%, 3.0%, and 1.0%, respectively. The egg positive rate of C. sinensis was higher in male (10.6%) than in female (6.1%), and the age group of 50s had the highest positive rate (10.4%).
  
  
  CONCLUSIONS
  The result of this study revealed little decrease in positive rate of C. sinensis compared with the result of southern endemic areas of Korea in 2006.
authors.affiliation: Division of Malaria and Parasitic Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Seoul, Korea.
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Kim
authors.forename: Hyeng-Il
authors.initials: HI
authors.lastname: Cheun
authors.forename: Byung-Suk
authors.initials: BS
authors.lastname: Cheun
authors.forename: Ki-Yeon
authors.initials: KY
authors.lastname: Lee
authors.forename: Tong-Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Sang-Eun
authors.initials: SE
authors.lastname: Lee
authors.forename: Won-Ja
authors.initials: WJ
authors.lastname: Lee
authors.forename: Shin-Hyeong
authors.initials: SH
authors.lastname: Cho
keywords: Clonorchis sinensis; five major rivers; intestinal parasites; prevalence