• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.567-577
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• 2020

The infection of marine diatom Coscinodiscus wailesii by a parasitic protist from the Yongho Bay of Busan, Korea was observed during the diatom bloom events in 2017 through 2018. The morphological and molecular features suggested that the parasitic nanoflagellate Pirsonia diadema was responsible for the infection. During the study period, the parasite prevalence ranged from 0.3% to 3.3%, and infected C. wailesii cells were observed only at surface seawater temperatures ranging between 10.9 and 19.9℃, although the host population appeared at temperatures above 25℃. The parasite and host system was successfully established as cultures. Using the cultures, we determined the morphological features over the infection cycle, parasite generation time, parasite prevalence as a function of inoculum size, and zoospore infectivity and survival time. The diatom C. wailesii was readily infected by the parasite P. diadema, with a parasite prevalence reaching up to 100% and a zoospore to host inoculum ratio above 20:1. The survival and infectivity of the parasite zoospores decreased with age. While the zoospores could survive up to 88 hours, they quickly lost their ability to infect after 48 hours. These results could lead to a better understanding of the biology and ecology of the parasitoid infecting the giant-sized diatoms in coastal waters.

• Parasites, Hosts and Diseases
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• v.54 no.2
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• pp.215-219
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• 2016

Clonorchis sinensis is currently the most important parasite affecting public health problems in the Republic of Korea. We investigated the prevalence of C. sinensis infection among residents living along 5 major rivers in Korea. A total of 42,562 individual stool samples were collected from 37 localities and examined using the formalin-ether sedimentation technique. Helminth eggs were detected in 4,052 (9.5%) residents and 3,586 (8.4%) were infected with C. sinensis. The egg positive rate of C. sinensis in Nakdong, Seomjin, Geum, Yeongsan, and Han River was 11.7%, 9.9%, 6.5%, 3.1%, and 1.0%, respectively. The overall prevalence of clonorchiasis by sex was 11.2% in males and 6.2% in females. The age-prevalence was the highest in the 50-59 years band. It has been reconfirmed that the endemicity of clonorchiasis is higher in southern areas of Korea, especially along Nakdong and Seomjin Rivers. A combination of continuous control programs with health education initiatives is urgently required in these highly endemic areas of clonorchiasis in Korea.

• Parasites, Hosts and Diseases
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• v.38 no.4
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• pp.275-277
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• 2000

The status of intestinal parasite infections was investigated in two rural villages (Chitrasar, Jerona) in Chitwan District, Nepal in 1999. Stool examination was performed with a total of 300 specimens from schoolchildren by formalin-ether sedinentation technique. The prevalence rate of intestinal parasite infections in the surveyed areas was 44.0%. The prevalence rate in Jerona was slightly higher than that in Chitrasar. The prevalence rate of intestinal parasite infections in female was slighly higher than that in male without statistically significant difference. Entamoeba coli was the most commonly found protozoan parasite (21.0%) followed by Giardia lamblia (13.7%) and others (5.3%). Hookworm was the most prevalent intestinal helminth (13.0%) followed by Trichuris trichiura (3.0%) and others (5.0%). forty-three specimens (14.3%) Showed mixed infections. It is necessary to implement large-scale treatment with anthelminthics, health education and sanitary improvement for intestinal parasite control in the surveyed areas.

• Parasites, Hosts and Diseases
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• v.57 no.3
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• pp.243-248
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• 2019

The purpose of this study was 2-fold: 1) to investigate the prevalence of gastrointestinal parasite infection in cats reared in Daegu, Republic of Korea and 2) to assess the efficacy and safety of a topical emodepside/praziquantel formulation for cats with parasitic infections. The gastrointestinal parasite infections were examined microscopically using the flotation method. Of 407 cats, 162 (39.8%) were infected by at least one gastrointestinal parasite, including Toxocara cati (63.0%), Toxascaris leonina (31.5%), Taenia taeniaeformis (3.7%), and Cystoisospora felis (1.9%). None of the infected animals had multiple infections. When the data were analyzed according to sex, age, and type of cat, stray cats showed statistically higher prevalence than companion cats (P<0.05). On the 5th day after treatment, no parasitic eggs were detected using microscopic examination. In addition, no adverse effects, such as abnormal behaviors and clinical symptoms, were observed in the cats treated with the drug. These results quantify the prevalence of gastrointestinal parasites in cats in Daegu, Republic of Korea, and show that topical emodepside/praziquantel is a safe and effective choice for treating the parasitic infections in cats.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.357-361
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• 2013

Several epidemiological surveys have reported the prevalence of Toxoplasma gondii infection in stray cats in Korea, but little information is available on T. gondii infection in household cats. The aim of the present study was to assess the prevalence and risk factors of T. gondii infection among household cats reared in Seoul, Korea. A total of 474 blood samples were collected from clinically healthy household cats. All samples were tested using ELISA and PCR. The risk factor analysis was based on a questionnaire filled out by the owners. The overall positive rate for ELISA and PCR assays was 2.2% (10/437) and 2.1% (10/474), respectively. With regard to the origin of cats, the positive rates among cats adopted from the animal shelter and veterinary clinic for stray cats were significantly different (P<0.05). Our study demonstrated that the positive rate of T. gondii infection in household cats was low and that this low prevalence was assumed to be associated with keeping the cats indoors and restriction of eating raw food and uncooked meat. Therefore, we suggest that the owners check the origin of the cats prior to adoption to prevent infection of other animals, including humans.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.33-40
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• 2005

Occurrence and prevalence of Marteilioides chungmueasis have been reported in several waters around Tongyeong but no report has been made for Pukman bay. Therefore, we investigated that the prevalence and infection intensities in Pukman Bay at the inside and the outside areas which are hydrographically divided by tidal current. Furthermore, various environmental parameters were investigated in order to elucidate effective parameter for parasitic infection. Infection rates of Marteilioides chungmuensis in adult oysters were ranged 3.3-20.0% at the inside area during September 2002 through January 2003, and 3.3-30.9% at the outside area during August 2002 through January 2003. External manifestation of infected oyster consisted of abnormal egg masses with nodular appearance in the soft tissue. Histopathological symptoms included massive hemocytic infiltration within or around the follicle wall and atrophic epithelium of digestive diverticula. For the environmental parameters, comparative study made differences between two side of the Bay during the infection period: inside > outside for SS while inside < outside for chlorophyll-a. A positive relationship was observed between chlorophyll-a and infection period, which might indicate the difference in food availability between two areas. The prevalence of ovarian parasite Marteilioides chungmuensis, therefore, was highly associated with food availability. Pearson's correlation analysis was made between environmental parameters and infection prevalence. Significance was observed in water temperature (p < 0.05), suspended solids (p < 0.01) and chlorophyll-a (p < 0.05). A principle component analysis showed that infection of the ovarian parasite, Marteilioides chungmuensis, exhibited effects of seasonality (component I = 55.2%) and chemical/physical environmental factors (component II = 24.4%). These results clearly indicate that the infection of ovarian parasite, M. chungmuensis in the Pacific oyster Crassostrea gigas is closely associated with seasonality and food availability.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.329-339
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• 2019

Indonesia and South Korea have become inseparable in various respects since the 2 countries established diplomatic relation in 1973. Indonesia is a tropical region that stretches across the equator, comprised of 5 main islands (Java, Kalimantan, Sumatra, Sulawesi, and Papua) and 4 archipelagoes (Riau, Bangka Belitung, Nusa Tenggara, and Maluku). As most population of Eastern Indonesia (Sulawesi, Papua and Nusa Tenggara & Maluku) live in poor areas, it is expected that there will be many parasites. Nevertheless, little is known about the status of parasites in Indonesia. This study examines the prevalences of malaria and lymphatic filaria, which are prevalent in Indonesia, as well as those of soil-transmitted-helminths (STH). As a result, the Plasmodium falciparum and P. vivax case loads are almost equal. The current prevalence of P. vivax is uniformly low (<5%) in all age groups and annual parasite incidence (API) showed decreasing tendency as 0.84 per 1,000 population in 2016. However, more than 65 million people still live in malaria epidemic regions. Lymphatic filariasis remains an important public health problem and 236 cities were classified as endemic areas in 514 cities/districts in 2017. It is difficult to ascertain the current prevalence rate of STH in Indonesia, although West Sumba and Southwest Sumba in East Nusa Tenggara reported prevalence rate of more than 20%. The study also considers the (sero) prevalences of other parasites identified in Indonesia. This report should be useful not only to parasitologists but also to travelers and people with business in Indonesia.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.579-582
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• 2017

To investigate the prevalence of intestinal parasite infections in Yanbian Prefecture, Jilin Province, China, epidemiological surveys were conducted on a collaboration basis between the Korean Centers for Disease Control and Prevention and the Yanbian Center for Disease Control and Prevention. A total of 8,396 (males 3,737 and females 4,659) stool samples were collected from 8 localities and examined with the formalin-ether sedimentation technique, and additionally examined with the cellotape anal swab to detect Enterobius vermicularis eggs. The overall rate of intestinal parasites was 1.57%. The prevalence of Ascaris lumbricoides was the highest (0.80%), followed by Entamoeba spp. (0.23%), heterophyid flukes (0.15%), Clonorchis sinensis (0.08%), Enterobius vermicularis (0.07%), hookworms (0.06%), Trichostrongylus spp. (0.06%), Giardia lamblia (0.04%), Paragonimus spp. (0.02%), Diphyllobothrium spp. (0.02%), Trichuris trichiura (0.02%). The prevalence by sex was similar, 1.58% (n=59) in males and 1.57% (n=73) in females. By the present study, it is partly revealed that the prevalences of intestinal parasite infections are relatively low among the inhabitants of Yanbian Prefecture, Jilin Province, China.

• Journal of Korea Association of Health Promotion
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• v.3 no.1
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• pp.62-71
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• 2005

In order to investigate the epidemiological situation of intestinal parasite infections in Lao PDR, parasitological surveys were carried out on a national scale including 17 Provinces and the Vientiane Municipality. A total of 29,846 stool specimens were collected from primary schoolchildren in May 2000 June 2002 and examined once with the cellophane thick smear technique. The cumulative egg Positive rate For intestinal helminthes was 61.9%, BV species, the rate for As caris lumbricoides was 34.9%, hookworm 19.1%, Trichuris trichiura 25.8%,Opisthorchis viverrini 10.9%, Taenia spp. 0.6% and Hymenolepis spp. 0.2%. The northern mountainous regions suck as Phongsaly, Huaphan or Saysomboune Province showed higher prevalence(over 70%) of soil- transmitted helminthes. The regions along the Mekong River such as Khammuane, Saravaue or Savannakhet Province showed higher prevalence(over 20%)of fish-borne parasites. On the other hand, Schistosoma mekongi eggs were detected from1.7% of schoolchildren only in Champassak Province, a previously known endemic area. The highest prevalence was noted in Phongsaly Province(96.0%) and the lowest in Bolikhamxay Province(27.5%). An additional smal1-scale survey by cellophane anal swab detected Enterobius vermicularis eggs in 35.7% of 451 schoolchildren aged 6-8 in Khammuane, Vientiane, Champassak Province and the Vientiane Municipality. Meanwhile, the mean blood hemoglobin level of hootrworm-infected children was not lower than that of hookworm-uninfected children, suggesting that nutritional factors are more important than parasite infection per se. Nevertheless, the above results indicate that a nationwide parasite control project is necessary to reduce possible morbidity of parasitic diseases in the country.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.41.1-41.12
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• 2024

Importance: Equines are indispensable in reducing the huge burden on children and women and income generation. On the other hand, minimal attention is given to improving their health and welfare. Objective: This study examined the prevalence and associated risk factors of helminth parasites of equine in the Gamo Gofa Zone. Methods: A cross-sectional study was employed from June 2019 to March 2020. The study districts and Kebeles were selected purposively based on agroecology whereas selection of study households and animals were performed based on simple random sampling techniques. Identification of nematode, trematode parasite ova and larvae of D. arnfieldi were done by floatation, sedimentation, and Baermann techniques respectively. Descriptive statistics and logistic regression was applied to estimate the prevalence and association of risk factors with helminth parasites. Results: The overall helminth parasite prevalence in the study area was 90.4%, 425/470 (95% [CI], 87.16-92.9). The prevalence of Strongyle, Fasciola, O. equi, P. equorum, D. arnfieldi, and mixed parasite infections were 65.1%, 21.7%, 17.4%, 34%, 34%, and 58.1%, respectively. Infections from Fasciola species and D. arnfieldi infection were four ([AOR], 4.4; 95% CI, 2-9.4) and two times (AOR, 2; 95% CI, 1.1-3.6) respectively more likely occur in donkeys than in mules. The occurrence of Strongyle species in midland agroecology was two times (AOR, 2.6; 95% CI, 1.4-4.7) more likely than lowland agroecology. Conclusions and Relevance: The present study identified diverse species of equine helminth parasites that necessitate urgent disease control and prevention measures.