• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.209-212
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• 1986

The present study was undertaken to evaluate the present status of intestinal parasitic infection in Seoul area, Korea. During the period from June 1985 to July 1986, a total of 5,251 stool samples were collected in Department of Clinical Pathology, Hanyang University Hospital and examined by formalin-ether sedimentation technique once for helminth ova and protozoan cysts. The results were summarized as follows: 1. The overall egg positive rate of intestinal helminthes was 2.53%; and 1.43% for Clonorchis sinensis, 0.7% for Trichuris trichiura, 0.13% for Metagonimus yokogawai, 0.06% for hookworm, and 0.02% for Ascaris lumbricoides, Diphyllobothrium latum and Hymenolepis nana, respectively. 2. The overall cyst positive rate of intestinal protozoa was 1.07%. Cyst positive rate was 0.06% for Entamoeba histolytica and 0.13% for Giardia lamblia, respectively. 3. Higher prevalence of intestinal parasitic infection was observed in male and in $21{\sim}50$ year-old groups. 4. The highest prevalence of Clonorchis sinensis infection was observed in 40th age group (3.4%), and male (2.3%) was more infected than female (0.7%) in general.

• Biomedical Science Letters
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• v.2 no.2
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• pp.267-274
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• 1996

This study was performed to observe the present status of intestinal parasitic infections among the children in Iksan, Jeonbuk, Korea. During the period from February to June 1996, total 510 fecal samples(male 276, female 234) were collected and examined by formalin-ether sedimentation technique and trichrome stain for intestinal helminths and protozoan cysts. Of 510 samples examined, 62(12.2%) were positive for intestinal parasites. Helminth egg positives were 3(0.6%), and protozoan cyst positives were 59(11.6%). The female group showed higher positive rate(13.2%) than males(11.2%), and the highest positive rates were observed in 7 age group(17.5%), and lowest positive rates were 4 age group(9.5%). 3 species of helminths egg and 6 species of protozoan cyst were detected; Metagonimus yokogawai 0.4%, Enterobius vermicularis 0.2%, Trichuris trichiura 0.2%, Endolimax nana 4.1%, Entamoeba coli 3.9%, Ciardia lamblia 2.0%, Entamoeba histolytica 1.4%, Iodamoeba butschilii 0.8%, and Chilomastix mesnili 0.4%, respectively. In 3 helminth egg positive cases, single infection was 2(66.7%), and double infection 1(33.3%), among 59 protozoan cyst positives, single infection was 54(91.5%), and double infection was 5(8.5%). The highest positive rate of protozoan cyst was 7 age group(14.3), and lowest positive rate was 4 age group(9.5%).

• Parasites, Hosts and Diseases
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• v.47 no.1
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• pp.37-47
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• 2009

National surveys on the prevalence of intestinal parasitic infections have been carried out every 5-7 years since 1971 in the Republic of Korea in order to establish control measures. The present nationwide survey was conducted from June to December 2004. The 10% population sampling data of Population and Housing Census by the Korean government in 2000 was used as the survey population. One sample was selected randomly from each of the 22,858 registered subjects, and a total of 20,541 people were ultimately included in this survey. Fecal examinations were performed by the cellophane thick smear and saturated brine flotation techniques. Pinworm infection was examined by cello-tape anal swab method. This survey also included a questionnaire study for a socioeconomic analysis. The total helminth egg positive rate was 3.7%, and the estimated total positive number among nationwide people was 1,780,000. The rates in urban and rural areas were 3.1% and 6.8%, respectively. As the total egg positive rate in the 6th survey in 1997 was 2.4%, the present survey showed that there was a considerable degree of increase in the prevalence rate of intestinal parasitic infections over the 7-year period following the 6th survey. The largest increases occurred in the egg positive rates of Clonorchis sinensis and heterophyids including Metagonimus yokogawai.

• Parasites, Hosts and Diseases
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• v.58 no.1
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• pp.67-72
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• 2020

Human infection with Echinostoma aegyptica Khalil and Abaza, 1924 (Trematoda: Echinostomatidae) is extremely rare. In this study, we confirmed E. aegyptica infection in 5 riparian residents living along the Mekong River in Savannakhet Province, Lao PDR. The patients revealed eggs of Opisthorchis viverrini/minute intestinal flukes, echinostomes, and other parasites in fecal examinations using the Kato-Katz technique. Following treatment with praziquantel 30-40 mg/kg and pyrantel pamoate 10-15 mg/kg in a single dose and purging with magnesium salts, adult specimens of various helminth species were collected. Among the trematodes, echinostome flukes of 4.5-7.6 mm in length (n = 134; av. 22.3 specimens per case) were of taxonomic interest and subjected in this study. The flukes were morphologically characterized by having total 43-45 collar spines arranged in 2 alternating rows (corner spines usually 5 on each side) and compatible with previous descriptions of E. aegyptica. The patients were mixed-infected with other helminths, so specific clinical manifestations due to this echinostome fluke were difficult to determine. The present paper describes for the first time human E. aegyptica infections in Lao PDR. This is the second report of human infection (2nd-6th cases) with E. aegyptica in the world following the first one from China.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.215-222
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• 1984

During February 1982 to September 1983, a total of 105 domestic ducks (Anas platyrhynchos var. domestica Linnaeus) were collected from Ichon Gun, Pusan City, Chunchon City, Yanggu Gun, Taejeon City and unknown areas in Korea. In the results, six trematode and one nematode species of helminth parasites were obtained and described as follows: Amphimerus anatis Yamaguti, 1933, Echinostoma miyagawai Ishii, 1932, Echinochasmus japonicus Tanabe, 1926, Cryptocotyle sp., Notocotylus attenuatus (Rudolphi, 1809) Kossack, 1911, Apatemon sp. and nematode species, Heterakis gallinarum Schrank, 1788. From this collection, Amphimerus anatis Yamaguti, 1933, Echinochasmus japonicus Tanabe, 1926, genus Cryptocotyle Liihe, 1899 and genus Apatemon Szidat, 1928 were firstly recorded in Korea.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.65-68
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• 1995

We examined stool specimens of the residents in the emigi·ation camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entnmoeba coli (29.3%) Giardio lomblia (9.8%), Entamoebo histolytica (7.6%), and eggs of Tqenic app. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.

• Parasites, Hosts and Diseases
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• v.38 no.3
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• pp.179-181
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• 2000

Stool and cellotape anal swab examinations were carried out in August 1997 on handicapped people at an institution located in Chorwon-gun, Kangwon-do, Korea. A total of 112 stool samples (78 males and 34 females) revealed three cases of Trichuris trichiura infection and one case of Enterobius vermicularis infection. Other helminth eggs were not detected. The overall prevalence rate was 35.7% (38.5% for males and 29.4% for females). More than two different kinds of parasites were found in 42.0% of the positive stool samples (17 cases). The infection rates for protozoan cysts are as follow : Entamoeba coli (25.0%), E. histoIUtica (1.8%), Endolinax nana (21.4%), Iodoamoeba butschlii (1.8%) and Giardia lamblia (0.9%). In cellotape anal swab examinations (165 samples), the prevalence rate of E. vemicularis was 20.6% (25.7% of males and 9.6% of females). In conclusion, the handicapped people in the institution showed higher infection rates of protozoan parasites and E. vemicularis, possibly due to more accessibility to the infection.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.673-678
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• 2016

Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the 'true' prevalence of S. stercoralis.

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.133-138
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• 2010

Infection status of intestinal flukes was investigated in residents of Muan-gun, Jeollanam-do, the Republic of Korea. Total 1,257 fecal samples of residents were examined by formalin-ether sedimentation technique and Kato-Katz thick smear method. Helminth eggs were detected from 95 (7.6%) residents, and eggs of heterophyid flukes and Clonorchis sinensis were found from 62 (4.9%) and 40 (3.2%) cases, respectively. The larger heterophyid eggs, somewhat darkbrown in color and $37.7{\times}21.5{\mu}m$ in average size, and found in 32 (2.6%) out of 62 egg positive cases of heterophyid flukes. To confirm the adult flukes, we performed worm recovery from 12 cases after praziquantel treatment and purgation with $MgSO_4$. A total of 1,281 adult flukes, assigned to 7 species, were recovered from 9 cooperative cases. Heterophyes nocens (total 981 specimens) was collected from 9 cases, Stictodora fuscata (80) from 7, Gymnophalloides seoi (75) from 5, Pygidiopsis summa (140) from 3, Stellantchasmus falcatus (3) from 2, and Stictodora lari and Acanthotrema felis (each 1 worm) from 1 case each. The intrauterine eggs of S. fuscata collected from the recovered worm were identical with the larger heterophyid eggs detected in the stool examination. By the present study, it was confirmed that A. felis is a new intestinal fluke infecting humans, and residents in Muan-gun, Jeollanam-do are infected with variable species of intestinal trematodes.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.523-532
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• 2017

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.