• Parasites, Hosts and Diseases
• /
• v.23 no.2
• /
• pp.197-202
• /
• 1985

During 8 April 1983 to 9 April 1985, a total of 181 domestic cats (Felis catus domestica Linnaeus) of unknown localities in Korea were purchased at Seoul Chung-ang market, and the internal organs were dissected for helminth infections. In the results, three kinds of trematodes of family Heterophyidae (Ohdner, 1914) were obtained from small intestine of domestic cats and identified as follows; five adult worms of Heterophyopsis continua (Onji et Nishio, 1916) from three hosts, two hundreds and twenty three adult worms of Pygidiopsis summa Onji et Nishio, 1916 from seven hosts and twenty six adult worms of Heterophyes heterophyes nocens (Onji et Nishio, 1916) from three hosts. Among them, Heterophyopsis continua and Pygidiopsis summa had not been proved as natural infections of cats in Korea.

• Parasites, Hosts and Diseases
• /
• v.34 no.4
• /
• pp.283-285
• /
• 1996

Six metacercariae were found from the gill filaments of Conger myriaster purchased at Mokpo-shi in korean on September, 1996. Based on the morphology of the excysted specimen. we identified them as metacercariae of Heterophyosis continua, C. myriaster is a new intermediate host H. continua in the literature.

• Korean Journal of Veterinary Research
• /
• v.30 no.4
• /
• pp.479-485
• /
• 1990

This study was carried out to observe in vitro effect of praziquantel on the viability and internal organ changes of Heterophyopsis continua with light microscopy. Metacercariae were collected from the perch, Lateolabrax japonicus, by artificial digestion technique and fed to 2-week old chickens. Adult worms were recovered from the small intestines of chickens 8 days after infection. For working solutions, praziquantel was diluted with TC199 medium at the concentration of 0.01, 0.1, 1 and $10{\mu}g/ml$. To each petri dish containing 10ml of solution, 5~10 worms were introduced and incubated at $37^{\circ}C$. Motlity of worms was observed at 5, 15, 30, 60 minutes, 1, 2, 4 and 6 hours after incubation. For light microscopy, worms were fixed in 10% formalin under cover glass pressure and stained with Semichon's acetocarmine. The results were as follows: 1. In $0.01{\mu}g/ml$ praziquantel, the worms had their mobility until 6 hours post treatment. However, worms in over $0.1{\mu}g/ml$ of praziquantel contracted within 5 minutes and immobilized. 2. Intestine of the worm incubated in $0.001{\mu}g/ml$ praziquantel for 5 minutes was dilated and intestinal wall was thickened. 3. In incubated over $0.1{\mu}g/ml$ praziquantel, pharynx of the worm protruded out from oral sucker. 4. The lowest effective lethal concentration of praziquantel on H. continua was $0.1{\mu}g/ml$. The worms exposed to the drug were observed to be immobilized immediately after incubation in solutions of over $0.1{\mu}g/ml$ concentration. All of the worms in early period showed severe contraction and those in late period showed severe dilation.

• Parasites, Hosts and Diseases
• /
• v.34 no.1
• /
• pp.87-90
• /
• 1996

The third human case of natural infection by Heterophvopsis continuo in Korea was found in Chinju, Kyongsangnam-do. The case was a 53-year-old mn. He used to eat raw brackish and fresh water fish. After praziquantel treatment and purgation, H. continua were collected from the diarrheal stool together with Metononimw vokognwai, Heterophves nocens and Echinostona hokense. His clinical complaints were indigestion, epigastric discomport, poor appetite and fatigue. The complaints were considered rather due to heavy M. Wokoscwci infection.

• Korean Journal of Veterinary Research
• /
• v.30 no.4
• /
• pp.487-497
• /
• 1990

This study was carried out to observe in vitro effect of praziquantel on the tegumental changes of Heterophyopsis continua with scanning electron microscope. Metacercariae were collected from the perch, Lateolabrax japonicus, by artificial digestion technique and fed to 2-week old chickens. Adult worms were recovered from small intestine of chickens 8 days after infection. For working solutions, praziquantel was diluted with TC199 medium at concentration of 0.01, 0.1. 1 and $10{\mu}g/ml$. To each petri dish containing 10ml of solution, 5~10 worms were introduced and incubated at $37^{\circ}C$. For the scanning electron microscopy(SEM), the worms were fixed in cold 2.5% glutaraldehyde, dehydrated in a series of graded ethanol and freeze-dried. Dried specimen was mounted on stub and coated with gold and observed in an SEM. The results were as follows: 1. Severe tegumental alterations were recognized by scanning electron microscope. Bleb formation of tegument was observed in 5 minute group and most pronounced on anterior tegument of worms. The number and size of blebs increased as incubation time prolonged. 2. The surface destruction was more pronounced at ventral margin between the oral and the ventral suckers. 3. The sensory papillae were slightly affected, but destruction of tegumental spine was not recognized. 4. The effect of praziquantel on the worm was found dependent on the concentration and incubation time, however, the effect was more dependent upon the incubation time.

• Parasites, Hosts and Diseases
• /
• v.22 no.1
• /
• pp.51-60
• /
• 1984

Two cases of natural human infection by Heterophyopsis continua (Heterophyidae) were identified by collection of adult worms in 1983 in Korea. And in order to know the source of infection a study on fish intermediate hosts was performed along the southwestern coastal areas. The cases were 21 and 50 year old males residing in southern coastal areas. They had the clinical complaints of non-specific gastrointestinal symptoms such as epigastric pain and one of them also complained the discharge of tapeworm segments. Praziquantel in single dose of 10~15mg/kg was given followed by purgation with magnesium salt and 2 and 46 specimens of H. continua were collected from the diarrheal stools. They said to have eaten raw ilesh of several kinds of brackish water fishes. The results of fish examination for metacercarial infection were as follows: I. Seventeen (663.0%) out of 27 perches (Lateolabrax japonicus) and 10 (29.4%) out of 34 gobies (Acantkogobius flavimanus) harboured the metacercariae but none of 42 mullets (Mugil cepkalus) were found to harbour them. 2. The average metacercarial density in perches was 55.1 and 18.7 per fish respectively. And the majority of the metacercariae were collected from the muscle of body portions in these fishes. 3. After the metaeercariae were experimentally fed to two rats and one young dog. two adult worms were recovered from the dog while none from the rats. These worms were also identified as H. continua. From the results it was concluded that the brackish water flshes which the human cases said to have eaten were the source of infection.

• Parasites, Hosts and Diseases
• /
• v.23 no.1
• /
• pp.173-174
• /
• 1985

1984년 11월에 쩐남 장홍군 장흥읍에서 구입한 은어에서 자연감염된 요꼬가와흠충의 피낭유충을 분리하여 개 2마리에 실험감염시키고, 감염후 4주일 및 8주일에 도살하여 성충을 얻었다. 그 과정중에서 감염 제8주에 도살한 개의 회장에서 인eterephyepsis continua로 동정한 충체 3마죄를 요꼬가와흡충과 함께 얻었다. 이들 충체는 은어에서 분리하여 감염시킨 괴낭유충 140,000개중에 섞여 있었던 것에서 유래 하였다고 판단하였다. 따라서 은어를 노. continua의 제이중간숙주로 추가하는 것이 타당하다고 생각한다. 은어가 강 하구 반염수대에서 겨울철을 넘기거나 어린시절을 보내므로 그때에 적게나마 감염되는 것으로 생각하였다. Heterephyepsis continua(Onji et Nishio, 1916)의 우리 말 이름을 "긴이형휸충"으로 할 것을 제의한다.

• Parasites, Hosts and Diseases
• /
• v.46 no.2
• /
• pp.77-82
• /
• 2008

Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters located in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua; both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.

• Parasites, Hosts and Diseases
• /
• v.44 no.1 s.137
• /
• pp.7-13
• /
• 2006

Heterophyid metacercarial infections in brackish water fishes, i.e., perch, shad, mullet, redlip mullet, and goby, of Jinju-man (Bay), Kyongsangnam-do, Korea, were investigated using a digestion technique. Among 45 perch (Lateolabrax japonicus), the metacercariae of Heterophyopsis continua were found in $55.6\%$ (18.5 metacercariae per fish), Stictodora spp. in $28.9\%$ (3.6), and Metagonimus takahashii in $6.7\%$ (17.0). The metacercariae of H. continua were detected in 23 $(65.7\%)$ of 35 shad (Konosirus punctatus). Among 15 mullet (Mugil cephalus), the metacercariae of Pygidiopsis summa were found in $100\%$ (105.9 metacercariae per fish), Heterophyes nocens in $40.0\%$ (8.5), H. continua in $13.3\%$, and Stictodora spp. in $6.7\%$. Among 12 redlip mullet (Chelon haematocheilus), the metacercariae of P. summa were detected in $91.7\%$ (1,299 metacercariae per fish), H. nocens in $16.7\%$, and Stictodora spp. in $16.7\%$. Among 35 gobies (Acanthogobius flavimanus), the metacercariae of Stictodora spp. were found in $82.9\%$ (44.5 metacercariae per fish), and H. continua in $25.7\%$ (2.8). The adult flukes recovered from a cat experimentally infected with metacercariae from perches were compatible with M. takarashii. The results confirm that the estuarine fish in Jinju-man (Bay) are heavily infected with heterophyid metacercariae. Furthermore, it was found for the first time that the perch acts as a second intermediate host for M. takahashii.

• Parasites, Hosts and Diseases
• /
• v.28 no.1
• /
• pp.53-62
• /
• 1990

The growth and developmental pattern of H. continua was observed after experimental infection of their metacercariae to chicks. The recovery rate of worms from the chicks at 1 to 28 days post-infection(PI) was 12.8% in average. The rate remained fairly high for early 4 days of infection but decreased thereafter rapidly till 28 days PI. Most of the nukes, 91.9%, were recovered from the ileum of the chicks. In metacercariae, genital organs such as the ovary, testes, seminal vesicle, seminal receptacle and genital sucker were recognizable. At one day PI Mehlis'gland appeared, and at 2 days follicular vitellaria were observed. At 3 days PI, eggs were formed in the uterine tubule and increased in number as the worm grew old. The worms reached $2,990{\;}{\mu\textrm{m}}$ in length and $525{\;}{\mu\textrm{m}}$ in width at 28 days PI. Genital organs developed rapidly in early stages of infection but slowly thereafter to 28 days Pl, whereas non-genital organs developed steadily through the infection period. It was proved by this experiment that chicks should be a moderately suitable final host of H. continua.