A parasitological study on the possible toilet ruins of the Japanese colonial period in Korea

In the past decade, experts have conducted parasitological research on archaeological specimens in Korea to collect historical parasite infection data. In these studies, parasitologists successfully described the infection pattern of each parasite species in history. However, in the first half of the 20th century, archaeoparasitological reports have been scant. In 2021, we conducted a parasitological examination of a toilet-like structure that emerged in the early 20th century. This structure was built by stacking 2 wooden barrels; and in the study samples, we found ancient Trichuris trichiura, Ascaris lumbricoides (unfertilized), and Taenia spp. eggs and therefore proposed a higher possibility that the barrels could have been used as a toilet at the time. To understand how the antihelminthic campaign since the 1960s helped reduce parasite infection rates in Korea, more research should focus on early-20th-century toilet ruins.

Current status of Clonorchis sinensis and clonorchiasis in Korea: epidemiological perspectives integrating the data from human and intermediate hosts

Clonorchis sinensis is a carcinogenic liver fluke that causes clonorchiasis in humans. Clonorchiasis is prevalent in East Asian countries, and approximately 15–20 million individuals are estimated to be infected with this fluke globally. This review highlights the current status of C. sinensis and clonorchiasis in Korea from the epidemiological perspective involving the analysis of humans and intermediate hosts. Despite the recent decline in C. sinensis infection rate in Korea, C. sinensis infections remain endemic in 5 major river basins (Han-gang, Geum-gang, Seomjin-gang, Yeongsan-gang and Nakdong-gang; gang means river) with a high incidence of cholangiocarcinoma. A noticeable pattern involves increasing mild infections among patients diagnosed positive for C. sinensis eggs. The infection rate of C. sinensis metacercariae in the second intermediate host, freshwater fish, is also maintained at a substantial level. Thus, the One Health approach integrating different sectors and disciplines is recommended to accelerate and sustain control of C. sinensis, thereby leading to successful eradication. Health promotion via information dissemination and health education should be extended to prevent the consumption of raw freshwater fish by residents living in high-risk areas.

Review of Successful Control of Parasitic Infections in Korea

Korea had been one of hyperendemic countries of human parasitic infections until 1970s. In 1966, the Law for the Prevention of Parasitic Diseases was enacted, and the nationwide anti-parasitic control program began in 1969. The initiation of the national program was supported financially by Japan. The program included screening of whole students in Korea and treatment of all egg positive cases twice a year, and ended in 1995. In addition to student program, deworming campaign was run in the community, and 8 national status surveys were implemented from 1971 to 2012. Whole helminth egg positive rate was 84.3% in 1971 and decreased to 2.6% in 2012. Ascaris and other intestinal nematodes, Paragonimus, Taenia, and intestinal protozoa had decreased significantly throughout the country, but Clonorchis sinensis and intestinal trematodes are still prevalent locally in endemic areas. Lymphatic filariasis had been endemic in Jeju-do and other southern islands but elimination was endorsed in 2008. The control of parasitic infection in Korea was successful with statistical prevalence data, which can be a benchmarking model. In conclusion, the successful control in Korea could be achieved by social agreement of the priority, professional guidelines and systematic approach with good anthelminthics supply, and simultaneous economic growth.

[Drug Induced Liver Injury by Prophylactic Administration of Albendazole]

Albendazole is used as a typical antiparasitic agent worldwide. The side effects of albendazole may include nausea, vomiting, abdominal pain, dizziness, headache, alopecia, and increased liver enzymes. Mild elevation of the liver enzyme has been reported in more than 10% of cases, but drug induced liver injury was reported to be very rare. A 30-year-old woman visited the Dong-A University Hospital with anorexia, nausea, jaundice, and elevated liver enzyme. For diagnosis, other acute hepatitis etiologies were excluded, but the prophylactic administration of albendazole was verified. This paper introduces a case of drug-induced liver injury through the prophylactic administration of albendazole. Physicians should be aware of severe liver injury as one of the side effects of albendazole.

Infections of Soil-Transmitted Helminth in Refugees from North Korea

Soil-transmitted helminthiases (STH) are now no longer public health problems in the Republic of Korea (South Korea), but their status are unavailable in the residents of North Korea (NK) despite the expectation of large scale traffic and future reunification of the Korean Peninsula. A total of 20 female refugees from NK who had been admitted to the Division of Gastroenterology, Dankook University Hospital, were subjected in this study. Among them, 15 refugees were examined by the colonoscopy and 10 ones were examined with the stool examination (formalin-ether sedimentation). Both diagnostic methods were commonly adopted in 5 patients. Eggs of Trichuris trichiura were detected in 7 out of 10 refugees in the stool examination. In the colonoscopy, T. trichiura worms were found in 6 (40.0%) out of 15 refugees. Total 9 (45.0%) peoples were confirmed to be infected with human whipworms. Additionally, 1 case of clonorchiasis was diagnosed in the stool examination and a worm of Ascaris lumbricoides was discovered from a trichuriasis case. These findings suggested that STH is highly prevalent in NO, in which living conditions are not so good in the aspect of general hygiene and medical care.

A new method for estimating the prevalence of clonorchiasis in Korea: A proposal to replace arbitrary riverside sampling

South Korea presently uses an arbitrary sampling method to monitor the prevalence of Clonorchis sinensis infection in the endemic areas of the country. However, the present method is not standardized and focuses primarily on individuals who reside nearest to the mainstream river. We propose a new sampling method that combines cluster sampling with proportionate quota sampling to ensure that the entire endemic area is accurately represented. We tested the new method in Okcheon-gun, South Korea, and determined that the C sinensis infection prevalence (8.9%) in 2013 was higher than that (6.9%) estimated in 2012 when the arbitrary method was used. Additionally, no difference was observed in the prevalence based on the distance from the riverside areas, including branches and creeks, between the areas <1 and >1 km away from the riversides. Therefore, health authorities should place equal emphasis on all regions within the endemic areas. Based on the findings, we recommend the following: the clonorchiasis prevalence rate must be measured using probability sampling, (clear guidelines on survey coverage should be provided to include the riverside areas and all areas nearby branch streams, and regional cohorts should be created for continuous monitoring of prevalence rates across the region.

The changing pattern of parasitic infection among Korean populations by paleoparasitological study of Joseon Dynasty mummies

In the coprolites of 4 recently discovered Joseon mummies of Korea, we found Ascaris lumbricoides , Trichuris trichiura , Metagonimus yokogawai , Paragonimus westermani , and Clonorchis sinensis eggs. The current finding was compared with previous paleoparasitological data, and with recent national survey data from Korea. For A. lumbricoides and T. trichiura , similar patterns of infection prevalence were observed between the national survey of 1961 and our current Joseon data. Some of the trematode species (C. sinenesis and P. westermani) showed much higher infection prevalences among the Joseon Koreans than among their 1960s descendants. The present results indicate that the decrease in trematode infection rates might have begun earlier than was the case for nematode infection.