Parasitic amebae in Korea

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.

Fifty years of the Korean Society for Parasitology

In 1959, the Korean Society for Parasitology was founded by clinical scientists, specialists of public health, and 5 core parasitologists with experience in American science and medicine. The Society this year celebrates its 50th anniversary. Due to public health importance at the time of foundation, medical parasitology was the main stream for next 3 decades. Domestic problems of niche parasitic diseases, unlisted in 6 tropical diseases of major importance, had been studied by own efforts. To cope with the demand of parasite control, evaluation system for control activity was built up. Control activity against soil-transmitted nematodes, conducted for almost 3 decades, was evaluated as a success. Evaluation of praziquantel efficacy for clonorchiasis, paragonimiasis, and neurocysticercosis, population dynamics of Ascaris lumbricoides infection in a situation of continuous reinfections, diagnostic modalities of antibody tests combined with brain imaging developed for helminthiasis of the central nervous system and researches on intestinal trematodes were achievements in the first 30 years. During the recent 2 decades, science researches, such as cell and molecular biology of parasites and immunology of parasitic infections have been studied especially on parasitic allergens and proteolytic and anti-oxidant enzymes. Experiences of international cooperation for world health have been accumulated and would be expanded in the future.

Bibliometric analysis of the Korean Journal of Parasitology: measured from SCI, PubMed, Scopus, and Synapse databases

The Korean Journal of Parasitology (KJP) is the official journal of the Korean Society for Parasitology which is celebrating its 50th anniversary in 2009. To assess the contributions and achievements of the KJP, bibliometric analysis was conducted based on the citation data retrieved from 4 major databases; SCI, PubMed, Synapse, and Scopus. It was found that the KJP articles were constantly cited by the articles published in major international journals represented in these databases. More than 60% of 1,370 articles published in the KJP from 1963 to June 2009 were cited at least once by SCI articles. The overall average times cited by SCI articles are 2.6. The rate is almost 3 times higher for the articles published in the last 10 years compared to 1.0 for the articles of the 1960s. The SCI journal impact factor for 2008 is calculated as 0.871. It is increasing and it is expected to increase further with the introduction of the KJP in the database in 2008. The more realistic h-indices were measured from the study data set covering all the citations to the KJP; 17 for SCI, 6 for PubMed, 19 for Synapse, and 17 for Scopus. Synapse extensively picked up the citations to the earlier papers not retrievable from the other 3 databases. It identified many papers published in the 1960s and in the 1980s which have been cited heavily, proving the central role of the KJP in the dissemination of the important research findings over the last 5 decades.

Overview of Entamoeba histolytica and amebiasis in Korea with special reference to research notes

Amebiasis caused by Entamoeba histolytica infection has been a prevalent protozoan disease in Korea since old times. For this reason, a number of scientific publications in relation to this protozoa has totaled 186 so far in the literature, as of 1989. The subjects ranged from biology to its treatment and prevention. The overall achievement by scientists and clinicians in Korea has been meritorious in elucidating some of the pending problems in the areas of pathogenesis, diagnosis, and treatment. Among them, development of a culture method applying diphasic medium, studies on virulence of the strains collected in Korea, and a combination of aspiration method and chemotherapy to treat amebic liver abscess are seen to have been contributing to the eventual goal of reducing this protozoa infection from the land.

[Epidemiological Studies On Protozoan Infection In Gyeong-Gi Do And Jeonra Bug Do]

The present study was designed to elucidate the recent prevalence of the intestinal protozoa and to demonstrate the relationship on prevalence of the surveyed population with their academic career and living conditions. During the period from May to July 1981, total 2,735 fecal specimens were collected from the inhabitants of 11 areas in Gyeong-gi Do (province) near by Seoul City, and 6 areas in Jeonra Bug Do, southwestern part of Korea. The samples were fixed with SAF solution and were examined by formalin-ether sedimentation technique. The results are summarized as follows: Overall positive rate of intestinal protozoa was 11.1 %: Gyeong-gi Do, 10.7 %; Jeonra Bug Do, 11.7 %. Five species of intestinal protozoa were detected: Entamoeba histolytica 0.69 %, Entamoeba coli 5.52 percent, Endolimax nana 2.71 %, Giardia lamblia 2.23 %, Iodamoeba butschlii 0.l8 %. Highest positive rates among the examined areas were recognized: Incheon City of Gyeong-gi Do, 26.7 %; Im-sil Gun(county) of Jeonra Bug Do, 19.9 %. By species, E. nana showed the highest prevalence rate (13.74 %) in Incheon City, and E. histolytica (2.37 %) and E. coli (9.95 %) in Im-sil Gun. Prevalence of E. histolytica in rural areas was higher than in urban areas. No significant difference in the prevalence rate by sex and age was recognized, although the group under 10 years and over 60 years were lower than in other age groups. The highest positive rate of E. histolytica was observed in pauper group and significant linearity of prevalence rate of E. histolytica by monthly income was observed. The inhabitants who used conventional latrine showed higher prevalence, 11.5 %, than the group of inhabitants who used modified privy. Although no significant difference of positive rate was recognized by academic career, but the lowest prevalence rate was observed in college graduates. Over half of the surveyed population, 64.8 % has no experience on anthelmintic practice. Number of anthelmintic application resulted no difference in prevalence. In conclusion, prevalences of intestinal protozoa in Gyeong-gi Do and Jeonra Bug Do decreased remarkably in comparison with those of one decade before. However, economic level, academic career and anthelmintic administration seemed no essential reasons for such declination.

[A Survey On The Prevalence Of Intestinal Protozoan Cysts In Jeonlanam Do, Korea]

A survey on the prevalence of intestinal protozoan cysts was conductcd in Jeonlanam Do (Province), Korea in 1981. A total of 4,116 specimens was collected from 2,035 male and 2,086 female inhabitants in 4 urban and 7 rural areas. Each case was selected randomly to represent 1,000 inhabitants referred to the census in 1980. Formalin-Ether sedimentation technique was employed to concentrate the cysts and one Lugol's iodine stained smear was examined for each case. The results were summarized as follows: 1. The cases who passed out protozoan cysts of any kind were 9.1 % out of total 4,116 examined, and cumulative positive rate was 11.0 %. Among the positive cases, 16.5 % were infected by two or more species of protozoa. 2. Total 5 species of cysts were detected and the positive rates were as follows; Entamoeba histolytica 1.4 %, E. Coli, 4.9 %, Endolimax nana 2.5 %, Iodamoeba butschlii 0.4 % and Giardia lamblia 1.9 %. 3. The cyst positive rates varied greatly by the surveyed area. The positive rate in rural area was 11.6 % compared with 5.7 % in urban area. The highest rate was found 14.5 % in Gurye Gun (County) and the lowest 3.6 % in Mogpo Si (City). 4. Female showed much higher positive rate than male as 11.8 % compared with 6.4 % and the cumulative rate 14.2 % and 7.6 % respectively. By age group, the rate was highest as 13.9 % in 40~49 years and next 12.5 % in over 60 years group. The cyst prevalence rate diminished remarkably in Jeonlanam Do compared to previous records. However, the finding that 20.2 % of females of 40 years were the carrier of protozoan cysts was an important information in public health point of view.

[The Status Of Intestinal Protozoan Infections In Inhabitants Of Gangweon-Do, Korea]

To evaluate the status of intestinal protozoan infections in inhabitants of Gangweon-Do, Korea, a total of 1,310 stool specimens (male 669, female 641) was collected from 2 cities and 3 counties. They were examined routinely 1 time by the method of formalin-ether sedimentation technique. The results were as follows: 1. The positive rate for any kind of the intestinal protozoan cysts was 8.9 %. 2. A total of 6 kinds of the intestinal protozoan cysts were detected. The prevalence rate of each protozoa were; E. histolytica 0.8 %, E. coli 7.6 %, E. nana 1.4 %, I. butschlii 0.2 %, G. lamblia 0.5 % and C. mesnili 0.5 %. 3. Sogcho-city showed the highest positive rate as 15.2 %, Myeongju county was the next as 11.3 % and Weonju-city showed the lowest positive rate as low as 3.9 %. 4. By age, the highest positive rate was found in 20-29 age group(12.4 %). Female (9.5 %) showed a slight higher positive rate than male (8.4 %).