Since 2002, adult worms of human small liver fluke in some provinces were identified by morphology and confirmed by molecular method as Clonorchis sinensis in Thanh Hoa, Ninh Binh, Nam Dinh and Bac Giang province; Opisthorchis viverrini in Phu Yen and Binh Dinh province. This study, using polymerase chain reaction (PCR), a portion of the cytochrome oxidase 1 (410 nucleotide and 136 amino acid) of mitochondrial genome of adult worms of small liver fluke from human in Nghe An (CsNA) and Dong Nai (CsDN) province were amplified. The nucleotide and amino acid of these sequences was comparatively analyzed with the known Clonorchis sinensis (Nam Dinh strain). The analysis revealed that the Nghe An Clonorchis sp and Dong Nai Clonorchis sp (in human) were homology (99.5 - 99.8% nucleotide) and similar (100% amino acid) to the Nam Dinh Clonorchis sinensis (identification was done). Thus, the Nghe An and Dong Nai Clonorchis sp were identified as Clonorchis sinensis in Opisthorchiidae family, Clonorchis genus.
Helminths ; Trematoda ; Human

The outbreak of the lung fluke occurred in Sin Ho - Lai Chau in 1994 and Da Bac - Hoa Binh in 1998. The biological, clinical, epidemiological investigation and X-ray showed that there were more 2000 patients (the morbidity rate: 4%). All patients had a lung lesion in X-ray image... the major signs in X-ray were pulmonary nodules and cavity and pleurocele. It should distinguish the lung fluke and the pulmonary tuberculosis
Trematoda ; lung ; X-Rays

The total sequence of 18S rRNA and the neighbours including 1950 pairs of nucleotide (N) was received by PCR and expressed orderly. The examinated sample was 1 of 8 adult worms collected from 12.5 years old male patient. The worm was determined morphologically as Fasciolopsis buski. The comparison showed that in this intestinal fluke worm there is an almost absolutely analogous coefficient concerning nitrogen components of 18S rRNA in only 2 differences on 1950 N (0.01%) with the gene sequence of 18S rRNA kept in the bank of genes. In Viet Nam, this is the first molecular determination realized on human
Fasciolidae ; Trematoda ; RNA, Ribosomal, 18S

Ultrastructural studies on the integument of digenetic trematodes were investigated by several workers (Senft et al., 1961; Bjorkman and Thorsell, 1964; Burton, l966; Erasmus, l968; Morris and Threadgold, 1967, l968). Clonorchis sinensis is a common parasite of human beings in the Far East. But as far little has been written on ultrastructure of the integument of this parasite. This study was carried out systematically to elucidate the ultrastructure of the integument of adult C. sinensis, and the results are summarized as follows: The integument of C. sinensis was organized in two parts; the epidermis and the muscular layer. The apical surface and basal surface of the epidermis were covered with typical plasma membrane and irregularly invaginated from the surface. Plasma membrane at perisuckers was extremely folded and appeared as if the epidermis might be divided with the layer. The syncytial epidermis contained mitochondria and numerous secretory bodies, and which was connected by cytoplasmic processes to nucleated epidermal cells lying in the parenchyma. The mitochondriae, the secretory bodies, the granular endoplasmic reticulum, the Golgi bodies and the free ribosomes were present in the perinuclear cytoplasm of epidermal cells, but no organelle was observed in processes of epidermal cell except some secretory bodies. The fibrous layer consists of argentophile fiber and collagenous fiber, in which the circular muscle bundles and longitudinal muscle bundles were embedded. Bundles of muscle fiber are weIl developed at the perisucker, and mitochondriae in this portion contain many cristae as compared with any other parts of C. sinensis.
parasitology-helminth-trematoda-Clonorchis sinensis ; ultrastructure ; electronmicroscopy

The authors carried out histochemical studies on Clonorchis sinensis, especially, histochemical demonstration of carbonic anhydrase activity. Kurada's method was applied for the histochemicl staining in this study. The result obtained were summerized as follows : Carbonic anhydrase activity was intensely positive in oral sucker cells, reticular tissue cells, epithelium of the intestine and testes, more or less intensely positive in vitelline gland cells and yolk of eggs as well.
parasitology ; histochemistry ; trematoda ; helminth ; Clonorchis sinensis

Metacercariae were found from 6 samples among 4,382 Parlemon nipponensis which were caught at Podu, Kohung, Korea. The metacercaria was inclined as a larval stage of Paragonimus westermani by following reason: Semisulcospira libertina was the only one species which lives in Podu area. No other metacercaria except Paragonimus westermani were found from the craw or cray fish which were caught in the endemic aera. Metacercariae, ovary, testes and cuticular spines resmbled the characteristics of Paragonimus westermani, which have been described by previous workers.
parasitology ; helminth ; trematoda ; Paragonimus westermani ; metacercaria ; epidemiology

The in situ posture of anterior body of Metagonimus yokogawai was observed in experimental metagonimiasis of dog. The metacercariae were collected from naturally infected sweetfish by peptic digestion; a total of 8 dogs was orally infected with 10,000 metacercariae respectively. Two dogs were killed on 3 days, 9 days, 4 weeks and 10 weeks after the infection. The postures of worms in histological section of small intestine and of whole worms collected from the fixed intestinal mucosa were examined by light and scanning electron microscope. The results were summarized as follows: The recovery rates of worms were 42.6% on 3 days, 55.0% on 9 days, 33.2% on 4 weeks and 9.8% on 10 weeks after the infection respecively. In histological sections of small intesine, most of worms were found at intervillous spaces as ovoid sections of posterior body. However, many worms, especially in 3 day-old worms, revealed protruded anterior body in glandular lumens of crypt. Some sections of anterior body were bifurcated or sacculated. The worms collected from fixed intestinal mucosa under dissecting microscope exhibited a variety of postures. Many worms showed flat shapes with a concavity or curvatures. However, in many worms, the anterior body made a single or multiple protrusions. By SEM observation of protruded anterior body, a longitudinal groove was found. The frequency of worms with protuded anterior body decreased in 9 days, 4 weeks and 10 weeks than in 3 day-old worms. The above findings indicated that the anterior body of juvenile and adult M. yokogawai protruded to lumens of glandular crypt by folding their lateral protions to make a reversible tubelike structure. Frequent multiple protrusions were considered to be made to adapt the microniche of glandular crypts of dog intestine.
parasitology-helminth-trematoda ; Metagonimus yokogawai ; pathology ; intestine

Thin layer immunoassay was carried out to demonstrate antibodies against Clonorchis sinensis in sera from clonorchiasis patients. Saline extract of adult worm was used as antigen. TIA technique was performed as described earlier by Elwing et al. (1976), but agarose was used instead of agar. The antibody titres of sera in 60 clonorchiasis cases were higher than that of 10 healthy and 10 amoebiasis cases, but not different comparing with that of 10 paragonimiasis cases. Antibody titres in clonorchiasis gave no differences according to the age, sex, EPG in feces, eosinophilia degree of blood, level of alkaline phosphatase and transaminase (SGOT, SGPT) in sera. It is suggested that, after evaluation, the TIA might supplement or be used as an alternative to other immunodiagnostic tests already in use for the diagnosis of clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; immunology

Thin layer immunoassay was carried out to demonstrate antibodies against Clonorchis sinensis in sera from clonorchiasis patients. Saline extract of adult worm was used as antigen. TIA technique was performed as described earlier by Elwing et al. (1976), but agarose was used instead of agar. The antibody titres of sera in 60 clonorchiasis cases were higher than that of 10 healthy and 10 amoebiasis cases, but not different comparing with that of 10 paragonimiasis cases. Antibody titres in clonorchiasis gave no differences according to the age, sex, EPG in feces, eosinophilia degree of blood, level of alkaline phosphatase and transaminase (SGOT, SGPT) in sera. It is suggested that, after evaluation, the TIA might supplement or be used as an alternative to other immunodiagnostic tests already in use for the diagnosis of clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; immunology

In order to observe the growth and development of Fibricola seoulensis metacercariae, the tadpoles of Rana nigromagulata were experimentally infected with the cercariae. The metacercariae of various developmental stages were recovered from the tadpoles after 2 to 65 days of infection. They were prepared for morphological observation, and were given orally to mice to observe their infectivity. The following results were obtained. All of the tadpoles exposed to the cercariae were observed to harbour the larvae in their abdominal cavity. The young metacercariae of 2 days after infection were 121.1 micrometer long and 63.3 micrometer wide. They grow linearly for the first 14 days to be 262.0 micrometer long and 166.4 micrometer wide. Thereafter, no more growth recognized until 65 days. The larvae of 2 days old were similar with cercarial body and had 2 suckers, a pharynx, two ceca and a primordium of germ cells but no tribocytic organ. On the 8th day, they had tribocytic organ, and their morphology resembled that of mature metacercariae. The metacercariae younger than 10 days could not infect the mice. Only the metacercariae older than 14 days had infectivity. The recovery rate increased by the age of metacercariae from 19.0% in 14 days old to 70.0% in 40 days old. Above findings indicate that the tadpole is indispensible for metacercarial development and it needs at least 2 weeks for maturation. The tadpole is a pivotal host in the life cycle of F. seoulensis for connection between the snail and the frog.
parasitology-helminth-trematoda ; Fibricola seoulensis ; metacercaria ; development