Status and emerging issues in the use of praziquantel for treatment of human trematode and cestode infections are briefly reviewed. Since praziquantel was first introduced as a broadspectrum anthelmintic in 1975, innumerable articles describing its successful use in the treatment of the majority of human-infecting trematodes and cestodes have been published. The target trematode and cestode diseases include schistosomiasis, clonorchiasis and opisthorchiasis, paragonimiasis, heterophyidiasis, echinostomiasis, fasciolopsiasis, neodiplostomiasis, gymnophalloidiasis, taeniases, diphyllobothriasis, hymenolepiasis, and cysticercosis. However, Fasciola hepatica and Fasciola gigantica infections are refractory to praziquantel, for which triclabendazole, an alternative drug, is necessary. In addition, larval cestode infections, particularly hydatid disease and sparganosis, are not successfully treated by praziquantel. The precise mechanism of action of praziquantel is still poorly understood. There are also emerging problems with praziquantel treatment, which include the appearance of drug resistance in the treatment of Schistosoma mansoni and possibly Schistosoma japonicum, along with allergic or hypersensitivity reactions against praziquantel treatment. To cope with and overcome these problems, combined use of drugs, i.e., praziquantel and other newly introduced compounds such as triclabendazole, artemisinins, and tribendimidine, is being tried.
Artemisinins ; Benzimidazoles ; Cestoda ; Cestode Infections ; Clonorchiasis ; Cysticercosis ; Diphyllobothriasis ; Drug Resistance ; Echinostomiasis ; Fasciola ; Fasciola hepatica ; Humans ; Hymenolepiasis ; Hypersensitivity ; Opisthorchiasis ; Paragonimiasis ; Phenylenediamines ; Phosphatidylethanolamines ; Praziquantel ; Schistosoma japonicum ; Schistosoma mansoni ; Schistosomiasis ; Sparganosis ; Taenia ; Taeniasis ; Trematode Infections

BACKGROUND/AIMS: Although the overall infection rate of infection with parasites has decreased, the rate of food-mediated infection with parasites has not declined. This study was conducted to define the various endoscopic and clinical characteristics of gastrointestinal (GI) parasite infections diagnosed endoscopically. METHODS: We reviewed retrospectively the medical records including the endoscopic reports of 27 patients with GI parasite infections diagnosed endoscopically at University Hospital from January 1993 through September 2006. RESULTS: Among 27 patients with a GI parasite infection, 66.7% were female and food-mediated parasite infections including anisakiasis accounted for 77.8% of all of the infections. Soil-mediated parasites were still detected. Extremely rare cases of echinostomiasis and diphyllobothriasis were also identified. Abdominal pain was most frequent symptom (48.1%) and even intestinal or biliary obstructions were seen. The most common endoscopic finding was a visible worm, and various findings including the presence of a pseudotumor were observed. The median period from symptom onset to endoscopy was 15 days for anisakiasis with a pseudotumor compared to 1 day for anisakiasis without a pseudotumor. CONCLUSIONS: Endoscopy revealed the presence of various GI parasite infections as well as the presence of anisakiasis, a food-mediated parasitic disease. Various clinical and endoscopic features were seen, including GI bleeding, obstruction, and a pseudotumor. Therefore, a thorough endoscopic examination is required promptly together with detailed history taking concerning the consumption of raw fish.
Abdominal Pain ; Anisakiasis ; Diphyllobothriasis ; Echinostomiasis ; Endoscopy ; Female ; Hemorrhage ; Humans ; Medical Records ; Parasites* ; Parasitic Diseases ; Retrospective Studies

A case of breast sparganosis was confirmed by surgical excision of a worm (fragmented into 5 pieces) in a 59-year-old Korean woman suffering from a palpable mass in the left breast. Mammography and ultrasonography characteristically revealed the presence of several well-defined, isodense and hypoechoic tubular masses, in the upper quadrant of the left breast, each mass consisting of a continuous cord- or worm-like structure. During surgery, a long segment of an actively moving sparganum of Spirometra sp. and 4 small fragments of the same worm, giving a total length of 20.3 cm, were extracted from the upper outer quadrant of the left breast and the axillary region. The infection source remains unclear, because the patient denied ingesting any snake or frog meat or drinking untreated water.
Middle Aged ; Humans ; Female ; Diphyllobothriasis/*diagnosis/parasitology/pathology ; Breast Diseases/*parasitology/pathology/*surgery

Five cases of Diphyllobothrium latum infection were proved by collection of worms after treatment with bithionol, niclosamide or praziquantel, during 1975-1983. The patients were 4 males and one female aged 10-64 years residing in Seoul or Wando-gun, Chollanam-do, Korea. All of them remembered the history of eating several kinds of raw marine fish and 2 persons said they ate the raw flesh of perch, Lateolabrax japonicus. Three among them experienced abdominal pain, 2 natural discharge of a chain of segments, but none revealed any sign of anemia. The average egg size in stool varied 59-67 x 41-48 micrometer according to cases. The eggs were characterized by ovoid to elliptical shape, terminal operculum, and distinct abopercular protuberance. One naturally discharged segment (30 cm) and 4 complete strobilae (320~680 cm) with scolices obtained after treatments were examined. The morphological characters of proglottids such as rosette-form uterus with 3-6 loops, vaginal pore included in the cirrus sac, separated seminal vesicle from cirrus sac etc. were all compatible with D. latum. These are the 7th~11th cases of D. latum infection proved by worms in Korea.
parasitology-helminth-cestoda ; Diphyllobothrium latum ; case report ; diphyllobothriasis ; chemotherapy-praziquantel ; niclosamide ; bithionol ; praziquantel

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 62–67×42–45 μm. 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.
Asian Continental Ancestry Group* ; Base Sequence ; China* ; Diphyllobothriasis ; Diphyllobothrium* ; Eggs ; Electron Transport Complex IV ; Humans* ; Methods ; Ovum ; Parasitic Diseases ; Uterus

Diphyllobothrium nihonkaiense has been reported in Korea as Diphyllobothrium latum because of their close morphologic resemblance. We have identified a human case of D. nihonkaiense infection using the mitochondrial cytochrome c oxidase subunit I (cox1) gene sequence analysis. On 18 February 2012, a patient who had consumed raw fish a month earlier visited our outpatient clinic with a long tapeworm parasite excreted in the feces. The body of the segmented worm was 2 m long and divided into the scolex (head) and proglottids. It was morphologically close to D. nihonkaiense and D. latum. The cox1 gene analysis showed 99.4% (340/342 bp) homology with D. nihonkaiense but only 91.8% (314/342 bp) homology with D. latum. The present study suggested that the Diphyllobothrium spp. infection in Korea should be analyzed with specific DNA sequence for an accurate species identification.
Animals ; Cyclooxygenase 1/*genetics ; Diphyllobothriasis/*parasitology ; Diphyllobothrium/enzymology/genetics/*isolation & purification ; Female ; Helminth Proteins/*genetics ; Humans ; Mitochondrial Proteins/*genetics

A case of Diphyllobothrium latum infection in a 49-year old man is described, and diphyllobothriasis latum in the Republic of Korea is briefly reviewed. An incomplete strobila of a tapeworm, 95 cm in length, without scolex and neck, was spontaneously discharged in the feces of a patient. On the basis of morphologic characteristics of the worm and eggs, the worm was identified as D. latum. The patient was successfully treated with a single dose (15 mg/kg) of praziquantel. The most probable source of infection was salmon flesh according to the past history of the patient. The first case of D. latum infection was documented in 1971, and this is the 43rd recorded case in the Republic of Korea. The 43 cases were briefly reviewed. The patients' main complaints were gastrointestinal troubles, such as mild abdominal pain, indigestion, and diarrhea, and discharge of tapeworm segments in the feces. The suspected infection sources included raw or improperly cooked flesh of fresh or brackish water fish, including the perch, mullet, salmon, and trout.
Animals ; Anthelmintics/therapeutic use ; Diphyllobothriasis/drug therapy/*epidemiology/*parasitology ; Diphyllobothrium/anatomy & histology/*isolation & purification/pathogenicity ; Feces/parasitology ; Humans ; Korea/epidemiology ; Male ; Middle Aged ; Praziquantel/therapeutic use ; Treatment Outcome

Human diphyllobothriasis is a widespread fish-borne zoonosis caused by the infection with broad tapeworms belonging to the genus Diphyllobothrium. In mainland China, so far 20 human cases of Diphyllobothrium infections have been reported, and the etiologic species were identified as D. latum and D. nihonkaiense based on morphological characteristics or molecular analysis. In the present study, proglottids of diphyllobothriid tapeworms from 3 human cases that occurred in Heilongjiang Province, China were identified as D. nihonkaiense by sequencing mitochondrial cytochrome c oxidase subunit I (cox1) and NADH dehydrogenase subunit 5 (nad5) genes. Two different cox1 gene sequences were obtained. One sequence showed 100% homology with those from humans in Japan. The remaining cox1 gene sequence and 2 different nad5 gene sequences obtained were not described previously, and might reflect endemic genetic characterizations. D. nihonkaiense might also be a major causative species of human diphyllobothriasis in China. Meanwhile, the finding of the first pediatric case of D. nihonkaiense infection in China suggests that infants infected with D. nihonkaiense should not be ignored.
Adult ; Animals ; China ; Diphyllobothriasis/*parasitology ; Diphyllobothrium/classification/enzymology/*genetics/*isolation & purification ; Electron Transport Complex IV/genetics ; Female ; Helminth Proteins/genetics ; Humans ; Infant

Parasites transmitted by fish (=fish-borne parasites) and the diseases caused by them are briefly reviewed. The fish-borne parasites known to occur in the Republic of Korea are taxonomically classified as 23 helminth species, which include 5 species of nematodes, 16 species of trematodes, and 2 species of cestodes. Among them, Anisakis simplex, Clonorchis sinensis, Metagonimus yokogawai, Heterophyes nocens, Echinostoma hortense, and Diphyllobothrium latum are the most important species in public health points of view. The kinds of fish responsible for human infections include various species of fresh water fish, brackish water fish, and marine fish. Pathogenicity and clinical manifestations are variable according to different parasite species and immune status of the host. For prevention of these infections, avoidance of consuming raw or improperly cooked fish is important.
Anisakiasis ; Anisakis ; Cestoda ; Clonorchiasis ; Clonorchis sinensis ; Diphyllobothriasis ; Diphyllobothrium ; Echinostoma ; Echinostomiasis ; Fresh Water ; Helminths ; Heterophyidae ; Humans ; Methylmethacrylates ; Parasites ; Parasitic Diseases ; Polystyrenes ; Public Health ; Republic of Korea ; Trematode Infections ; Water

An excavation of the Vesakoyakha II–IV and Nyamboyto I burial grounds was conducted during the 2014 field season, and soil samples from intact burials dating from the 19th and 20th centuries, respectively, were analyzed to determine interactions between parasites and host/vectors. Considering the discovery of Diphyllobothrium sp. and Taenia sp. eggs in soil samples from the pelvic region, diphyllobothriasis was the most frequent helminthic infection among the Taz Nenets. The Nyamboyto Nenets mainly consumed uncooked fish, while the Vesakoyakha Nenets had a bigger variety in food choices, including reindeer meat. Nenets children were given raw fish from early childhood. The paleoparasitological results corroborate rare ethnographic records about the consumption of uncooked reindeer cerebrum which led to beef tapeworm helminthiases. This is the first parasitological report of helminthic diseases among the Taz Nenets, and, as such, it provides insight into their subsistence activities and food patterns and broadens our understanding of their health condition.
Burial ; Cerebrum ; Child ; Diphyllobothriasis ; Diphyllobothrium ; Eggs ; Food Habits ; Helminthiasis ; Helminths ; Humans ; Meat ; Ovum ; Parasites ; Pelvis ; Reindeer ; Seasons ; Soil ; Taenia ; Taenia saginata ; Tundra*