Status of Helminthic Infections in Residents around River Basins in the Republic of Korea for 10 Years (2011-2020)

Abstract

The positive rate of <i>Clonorchis sinensis</i> is the highest among intestinal parasites in the Republic of Korea (Korea). More than 1.2 million people were at risk of <i>C. sinensis</i> infection in Korea in 2012. An intensive control program is being implemented for residents of the 5 major river basins to reduce helminthic infections, including <i>C. sinensis</i> infection. This study evaluated the continuous intensive control program for parasitic diseases including clonorchiasis in areas near the 5 major river basins in Korea over the past 10 years (2011-2020). A total of 335,020 fecal samples (one sample per resident) prepared by the modified sedimentation technic were microscopically examined. Those who expelled helminth eggs were treated with anthelmintics through local health centers and re-examined 3 months later. The overall positive rate of helminths egg was 7.1%. The annual positive rates were dramatically decreased from 14.4% (2011) to 5.9% (2020). The egg positive rate was highest in <i>C. sinensis</i> (5.3%), followed by heterophyid flukes (1.5%) and <i>Trichuris trichiura</i> (0.2%). The prevalence of <i>C. sinensis</i> was significantly higher in males (7.6%) than in females (3.7%), and the highest in the 50–59 years (7.0%) age group. Our results are beneficial to establish prevention and control policies against helminthiases including clonorchiasis in endemic areas in this country.

Relationship between Clonorchis sinensis Infection and Cholangiocarcinoma in Korea

“…This is similar to the results of a recent study that investigated the status of C. sinensis infection around the 5 major river basins [29]. The dramatic decrease of infection rates of C. sinensis was observed around the 5 river basins of Nakdong, Seomjin, Geum, Yeongsan, and Han River from 2011 to 2020, but it was still relatively high around the Seomjin River [29]. The Korea Centers for Disease Control (KCDC) have been implementing efforts to reduce intestinal helminthiases and clonorchiasis nationwide, especially in endemic regions since 2005 [30].…”

“…Although the Gyeongsang region in the southeastern part of Korea had a high rate of clonorchiasis, it showed a decreasing trend. This is similar to the results of a recent study that investigated the status of C. sinensis infection around the 5 major river basins [29]. The dramatic decrease of infection rates of C. sinensis was observed around the 5 river basins of Nakdong, Seomjin, Geum, Yeongsan, and Han River from 2011 to 2020, but it was still relatively high around the Seomjin River [29].…”

“…The Korea Centers for Disease Control (KCDC) have been implementing efforts to reduce intestinal helminthiases and clonorchiasis nationwide, especially in endemic regions since 2005 [30]. KCDC tests about 50,000 people annually, and makes it possible for test-positive people to receive treatment, thus contributing to a 3 fold lower egg positive rate of C. sinensis in endemic areas [29]. Control measures of the responsible health authorities and increasing public awareness might have played a positive role in preventing the infection.…”