Human infections with liver and minute intestinal flukes in Guangxi, China: Analysis by DNA sequencing, ultrasonography, and immunoaffnity chromatography

Abstract

The prevalence of liver and intestinal fuke infections was determined by surveying inhabitants of Hengxuan, Fusui, and Shanglin villages which were known to be endemic for liver fukes in Guangxi, China in May 2010. A total of 718 people were examined for helminth eggs by the Kato-Katz thick smear technique, ultrasonography, immunoaffnity chromatography, and DNA sequencing. The overall egg positive rate was found to be 59.6% (28.0-70.6%) that included mixed infections with liver and intestinal fukes. Cases showing higher than 20,000 eggs per gram of feces (EPG) were detected between 1.3% and 16.2%. Ultrasonographic fndings exhibited overall 28.2% (72 of 255 cases) dilatation rate of the intrahepatic bile duct. Clonorchis sinensis infection was detected serologically in 88.3% (38 of 43 cases) among C. sinensis egg positive subjects by the immunoaffnity chromatography using a specific antigen for C. sinensis. For differential diagnosis of the liver and intestinal fukes, more precise PCR and nucleotide sequencing for copro-DNA were perform- ed for 46 egg positive cases. Mixed infections with C. sinensis and Metagonimus yokogawai were detected in 8 of 46 egg positive cases, whereas 29 specimens were positive for Haplorchis taichui. Ultrasonographic fndings and immunoaffnity chromatography results showed usefulness, even in a limited way, in fguring out of the liver fuke endemicity. © 2012, Korean Society for Parasitology and Tropical Medicine.