• Parasites, Hosts and Diseases
• /
• v.55 no.3
• /
• pp.319-325
• /
• 2017

We described 4 human infection cases of zoonotic fish-tapeworm, Diphyllobothrium nihonkaiense, identified with morphological and molecular characters and briefly reviewed Chinese cases in consideration of it as an emerging parasitic disease in China. The scolex and mature and gravid proglottids of some cases were seen, a rosette-shaped uterus was observed in the middle of the mature and gravid proglottids, and the diphyllobothriid eggs were yellowish-brown in color and displayed a small knob or abopercular protuberance on the opposite end of a lid-like opening. The average size of the eggs was recorded as $62-67{\times}42-45{\mu}m$. The parasitic materials gathered from 4 human cases were morphologically identified as belonging to the genera Diphyllobothrium and Adenocephalus. The phylogenetic analysis based on the nucleotide sequences of cytochrome c oxidase subunit 1 gene of the etiologic agents confirmed that the 4 cases were D. nihonkaiense infection. The finding of 4 additional D. nihonkaiense cases suggests that D. nihonkaiense might be a major causative species of human diphyllobothriasis in China. A combined morphological and molecular analysis is the main method to confirm D. nihonkaiense infection.

• Journal of fish pathology
• /
• v.24 no.3
• /
• pp.289-295
• /
• 2011

The in-vitro eliminative effects of against three types of herbal extract and formalin Ichthyophthirius multifiliis were examined. All parasites were killed within one hour after exposure to the 500 fold dilution of the complex herb extract whereas the 10 fold dilution of the fertilized solution of Salvia plebeia R. Br. killed all parasites within one hour after exposure. The 5,000 fold dilution of the extracts of Ginkgo biloba leaves killed all parasites within one hour after exposure. As a comparative agent, formalin killed all parasites within one hour at 100 ppm. As the results, the extracts of Ginkgo biloba leaves extracts have the most eliminative ability against the parasite. No differences were found among different parasite density in eliminative effects of the three types of herbal extracts and formalin. Also there were no changes in the fish gill tissues after exposure for two hours to the 5,000 fold dilution of the extract of Ginkgo biloba leaves.

• Journal of fish pathology
• /
• v.11 no.1
• /
• pp.69-76
• /
• 1998

An apicomplexan parasite, Perkinsus sp. was observed from the cultured baby clams, Ruditapes philippinarum, collected from the coast of Kochang and Taean (South Korea), where it caused seasonal mortality of clams. Several milky-white cysts were observed on the surface of gill and visceral mass of parasitised clams. The trophozoites of parasite had eccentric nucleus and proliferated by schizogony in gill, mantle, hepatopancrease and reproductive tissues, resulting in the formation of granuloma and the intensive infiltration of hemocytes in the tissues. During incubation in FTM, trophozoites increased in size, resulting in prezoosporangia which appeared as round black spheres when colored with Lugols iodine solution. The prevalence of Perkinsus sp. in clams was Kochang, 73.1%; Taean, 94.8% (during 9-mo. survey) and showed size-dependent infection. Hemacolor kit was useful to reduce time for diagnosis of the trophozoite of Perkinsus sp. that has been responsible of massive motalities in the clam.

• Journal of fish pathology
• /
• v.22 no.1
• /
• pp.1-7
• /
• 2009

To investigate the effect of hydrogen peroxide in israel carp, Cyprinus carpio, toxicity and microbial activities were determined. For hydrogen peroxide toxicity test, the median lethal concentration ($LC_{50}$) to israel carps Cyprinus carpio (average weight 0.44 g) by acute toxicity was determined after 24 hour treatment. All israel carp were alive in 24 hours treatment at 80 $\mu\ell/\ell$ concentration and $LC_{50}$ value was 148.9 $\mu\ell/\ell$. For biocidal activities of hydrogen peroxide, remove of parasite and growth inhibition of pathogenic bacteria were determined. The parasite Trichodina sp. infected on the skin and gills of israel carps (average weight 0.1 g) was completely eliminated at 40 $\mu\ell/\ell$ of hydrogen peroxide treatment for 24 hour. Most of the minimum inhibitory concentrations (MICs) against 30 fish pathogenic bacteria were less than 40 $\mu\ell/\ell$.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.3
• /
• pp.337-345
• /
• 2015

To investigate the causes of emaciation in cultured olive flounder Paralichthys olivaceus in Korea. We performed histological examinations and polymerase chain reaction (PCR) with a new primer set. In most cases, the most severe emaciation was observed in the abdominal area Using PCR on extracted livers, kidneys, spleens, gills, brains, and intestines, we found that areas around the kidneys and intestines were as almost always positive. In significantly emaciated fish, PCR was positive in all internal organs except the gills. In addition, the homology of 812-bp nucleotide sequences of the 28S rRNA gene was more than 99% in emaciated fish. Partial homology with Myxobolus spp. and Cystodiscus axonis, whose data were obtained from GenBank was 86% and 88%, respectively. Histological examinations detected spores in kidneys and intestines but not in other organs. We also performed cohabitation experiments to determine whether infections could be exchanged among species or only within species. Uninfected olive flounder and red sea bream, Pagrus major, cohabitating with emaciated olive flounder showed 100% and 0% cumulative mortality, respectively. Thus the cause of emaciation in cultured olive flounder of Korea is likely due to a new parasite.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.3
• /
• pp.258-265
• /
• 1993

Monthly changes in the occurrence and infection levels of a parasitic copepod Acanthochondria yui(Poecilostomatoida, Chondracanthidae) on a gobiid fish Acanthogobius flavimanus were studied for a year from April 1990 to March 1991. This parasite was not found on the fish for four months from September to December. Prevalence of the parasite increased from $2.9\%$ in January to $88.9\%$ in June. Relative density and mean intensity also increased from January to June. Prevalence of A. yui increased with host size. A. flavimanus samples were never found carrying A. yui larvae of three copepodid stages(CI to CIII), although a few CIV and CV larvae were identified from April and May samples. This indicates that A. flavimanus was not the sole host of A. yui. Adult females and copepodites of A. yui were usually found in the gill arch($74.8\%$) and gill filament($80.6\%$), respectively. This suggests that copepodites select the gill filament as the most suitable place on their host A. flavimanus, and the adult females move toward the gill arch.

• Parasites, Hosts and Diseases
• /
• v.45 no.1 s.141
• /
• pp.45-54
• /
• 2007

Although Vietnam has a high risk of fish borne zoonotic trematode(FZT) infections for humans, little information exists on the epidemiology of these infections in the country's fish. Because of the importance of cultured cat-fish and snakehead production in An Giang province, a major production area in the Mekong Delta of Vietnam, a survey for FZTs was carried out in randomly selected fish farms between June 2005 and March 2006. For comparison, wild fish from the same area were also surveyed. A total of 852 cultured fish from 4 districts were collected and examined by pepsin digestion to determine their FZT infection status. In Tra catfish, the prevalence of all types of metacercariae was 2.6%, of which the prevalence of Haplorchis pumilio was 0.7%. The overall prevalence of metacercariae in wild fish was 30.6%, of which 10.3% harbored zoonotic species: H. pumilio(2.8%) and Procerovum sp.(5.6%). The prevalence of Opisthorchis metacercariae, which were diagnosed as O. viverrini, was 1.9%. No metacercariae were found in cultured snake head fish, although wild-caught snakehead fish had a FZT prevalence of 10.3%: 5.1% were O. viverrini; 2.6% H. pumilio; and 2.6% were Procerovum sp. These are the first reports of H. pumilio, Procerovum sp., and O. viverrini metacercariae in Vietnamese fish. These results indicate that consumption of improperly prepared fish represents a significant risk of acquiring FZTs in this south Vietnam region.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.233-234
• /
• 2000

Formalin, 37% formaldehyde, has been employed as a chemical for controlling ectoparasites and aquatic fungi responsible for infectious fish of diseases in hatcheries and culture facilities (Roberts, 1978; Schnick, 1991; Rach et al., 1997). Regarding the commercial usage of formaldehyde in the aquaculture industry, the U.S. Food and Drug Administration (FDA) approved three commercial products as parasiticides in a species-specific manner: Paracide-F and Formalin-F for bluegill, catfish, largemouth bass, salmon, and trout and Parasite-S for all finfish (FDA, 1998). Withdrawal time for these products was legally zero when used as permitted under the regulations. With the increased production of cultured fish in Korea, such as olive Hounder Paralichthys olivaceus and black rockfish Sebastes schlegeli, application of formalin to diseased fish has become more frequent. Moreover, there is still some concern about environmental exposures caused by effluents from fish culture facilities. The purpose of the present study was to evaluate residues in fish resulting from therapeutic usage of formalin in the aquaculture industry and to document the rate of disappearance of formaldehyde in seawater treated with formalin. (omitted)

• Journal of fish pathology
• /
• v.31 no.2
• /
• pp.123-129
• /
• 2018

Parvicapsula anisocaudata, a myxosporean parasite, is presumably one of causative agents of emaciation in olive flounder Paralichthys olivaceus in Korea. In this study, we report a case of unusual abdominal distension due to exceptionally enlarged liver in farmed olive flounder. For the identification of the causative agent, bacteria and nucleic acids of virus that are possibly present were attempted to isolate from internal organs of five fish sampled from a fish farm in Jeju. Although a few bacterial colonies were isolated from some samples, there was no evidence that fish were primarily affected by virus and/or bacteria. From histopathological analysis, myxosporean were found in almost all internal organs, particularly in the stomach. The causative agent was identified as P. anisocaudata by sequencing a part of small subunit rRNA. This study contains a very unusual case of olive flounder heavily and systemically infected with P. anisocaudata, showing excessively enlarged liver with a small amount of ascitic fluid.

• Journal of agricultural medicine and community health
• /
• v.22 no.2
• /
• pp.239-252
• /
• 1997

A questionnaire survey including stool examination for the parasite ova, skin test, and enzyme-linked immunosorbent assay (ELISA) of the liver fluke to find the factors related with the prevalence of the parasite infestation was done toward 118 residents living in three villages of Song-jung, Yi-jung, and Chim-gok of Okok-myun, Goksung County, South Cholla Province. The results are as follows : 1. The prevalence of Clonorchis sinensis ova by the stool examination was 46.6%. The sensitivity and specificity of skin test to egg-positive cases were 63.5% and 68.9%. The sensitivity and specificity of ELISA to egg-positive clonorchiasis were 100% and 34.9%. 2. The prevalence of Clonchiasis was higher in male than in female. 45~64 year old group was the highest among age groups, and the longer the duration of living in the present residence was, the higher the prevalence was shown statistically significantly (p<0.01). 3. The present drinker had higher prevalence of Clonorchiasis significantly than the past drinker or non-drinker, and the more the frequency of drinking the higher the prevalence was shown significantly (p<0.05). 4. Those who took raw fish had significantly higher than persons who didn't take it or take cooked fish(p<0.05) and prevalence showed the tendency to be increased as the frequency to take raw fishes increased significantly(p<0.05). 5. Those who had taken a raw sweet fish(Plecoglossus altivelis) or snake-headed fish(Ophicephalus argus) showed significantly higher prevalence of infection with liver fluke than persons who didn't take the raw fish. 6. While 56.4% of persons infected with Clonorchiasis answered that they were healthy, only 13.0% of the subjects were careful for their health, and 41.8% experienced tests to diagnose liver flukes before they were examined by this survey. 7. While 56.4% of infected persons thought the prevalence was high in their community, 54.0% were afraid to be infected, 47.1% thought the infection might destroy their health, 25.5% took treatment drugs, and 18.2% took raw fish continuously after treatment. The above results confirmed that Goksung area was highly prevalent in Clonorchiasis, so it was necessary to push effective preventive program against liver fluke infection together with the program to diagnose and treat existing infected persons.