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

The transition of important parasitic diseases in Korea is briefly reviewed in this article. Soiltransmitted helminthiases, such as ascariasis, trichuriasis, and hookworm infections, which had been prevalent all over the country, decreased remarkably, largely owing to the national control activities by means of mass examination-mass treatment schemes for school students. Paragonimiasis has shown significant reduction in its incidence, but clonorchiasis still remains as an important health-threatening trematode infection. Intestinal trematodiases, including metagonimiasis, heterophyidiases, and echinostomiases are prevalent, and new species, such as Gymonphalloides seoi and Neodiplostomum seoulense, have been documented as new human parasitic diseases. Tapeworm infections including larval cestodiases are also decreasing. Among the protozoan infections, amebiasis and malaria showed an apparent decreasing trend, but in recent years, vivax malaria has become a re-emerging disease. Brugian filariasis, which was prevalent in southern parts of the Korean peninsula, has been completely eliminated nowadays. In terms of the prevalence and distribution, clonorchiasis, enterobiasis, and vivax malaria are currently the major parasitoses of public health importance in Korea.
Amebiasis ; Ascariasis ; Cestode Infections ; Clonorchiasis ; Echinostomiasis ; Enterobiasis ; Filariasis ; Helminthiasis ; Hookworm Infections ; Humans ; Incidence ; Korea* ; Malaria ; Malaria, Vivax ; Paragonimiasis ; Parasitic Diseases* ; Prevalence ; Protozoan Infections ; Public Health ; Trematode Infections ; Trichuriasis

Eosinophilic gastroenteritis is a rare disorder, characterized by increased eosinophil count and eosinophilic infiltration in gastrointestinal organ. Its etiology is unknown, but affected by parasitic infestation, collagen disorder, malignancy and allergic disorder. There have been several reports all over the world that Eustoma rotundum, Schistosomiasis, Ancylomastoma and Ascaris are the sources of parasites occurring eosinophilic gastroenteritis. But the reports on Metagonimus yokogawai have not presented yet. We experienced a case of metagonimiasis with a presentation of small bowel perforation by eosinophilic enteritis. A 35-year-old woman was admitted to the hospital because of epigastric pain. Six months ago, she had been treated as metagonimiasis. This time she took antiparasitic agent again, but abdominal pain was aggravated and perforation of small bowel was detected. The pathologic finding of resected small bowel showed perforation and obstruction with diffuse and dense eosinophilic infiltration.
Abdominal Pain ; Adult ; Ascaris ; Collagen ; Enteritis ; Eosinophils* ; Female ; Gastroenteritis* ; Heterophyidae ; Humans ; Parasites ; Schistosomiasis ; Trematode Infections*

Freshwater snails, as the first intermediate hosts of trematodes, can cause health hazards in animals and humans. Recently, the World Health Organization has included Iran in a list of 6 countries known to have serious problems with fascioliasis. In addition, cercarial dermatitis is a job-related disease that is seen often in paddy workers, agricultural labourers, and fishermen in Iran, particularly in Mazandaran Province. Many studies have been conducted in Iran to survey larval trematodes in freshwater snails. However, to the best of our knowledge, no comprehensive data exist regarding infections in gastropods. Therefore, the aim of the present study was to estimate the types and prevalence of cercarial infections in snails in Iran. Electronic English-language and Persian-language databases were searched to identify 24 published articles reporting the prevalence of trematode infections in snails (9 species from 6 families) in various provinces of Iran. In total, 4.4% of gastropods were infected with the larval stages of trematodes. According to the studies reviewed in this meta-analysis‚ the highest infection prevalence was found in Radix auricularia (9.9%). Twelve larval species of trematodes were identified, and the highest prevalence of cercariae was found for Echinostomatidae cercariae (4.3%). Among the provinces explored, West Azerbaijan had the highest prevalence of infected snails (16.9%). The presence of trematodes in snails could pose a serious health problem in Iran. Thus, further studies are necessary to characterize these infections in other provinces.
Animals ; Azerbaijan ; Cercaria ; Dermatitis ; Echinostomatidae ; Farmers ; Fascioliasis ; Fresh Water ; Gastropoda ; Humans ; Iran ; Prevalence ; Snails ; Trematode Infections ; World Health Organization

Freshwater snails, as the first intermediate hosts of trematodes, can cause health hazards in animals and humans. Recently, the World Health Organization has included Iran in a list of 6 countries known to have serious problems with fascioliasis. In addition, cercarial dermatitis is a job-related disease that is seen often in paddy workers, agricultural labourers, and fishermen in Iran, particularly in Mazandaran Province. Many studies have been conducted in Iran to survey larval trematodes in freshwater snails. However, to the best of our knowledge, no comprehensive data exist regarding infections in gastropods. Therefore, the aim of the present study was to estimate the types and prevalence of cercarial infections in snails in Iran. Electronic English-language and Persian-language databases were searched to identify 24 published articles reporting the prevalence of trematode infections in snails (9 species from 6 families) in various provinces of Iran. In total, 4.4% of gastropods were infected with the larval stages of trematodes. According to the studies reviewed in this meta-analysis‚ the highest infection prevalence was found in Radix auricularia (9.9%). Twelve larval species of trematodes were identified, and the highest prevalence of cercariae was found for Echinostomatidae cercariae (4.3%). Among the provinces explored, West Azerbaijan had the highest prevalence of infected snails (16.9%). The presence of trematodes in snails could pose a serious health problem in Iran. Thus, further studies are necessary to characterize these infections in other provinces.
Animals ; Azerbaijan ; Cercaria ; Dermatitis ; Echinostomatidae ; Farmers ; Fascioliasis ; Fresh Water ; Gastropoda ; Humans ; Iran ; Prevalence ; Snails ; Trematode Infections ; World Health Organization

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

The central nervous system involvement of Schistosomiasis is rarely reported in the literatures. The authors report a case of cerebellar Schistosomiasis. A 40-year-old man presented to our hospital with a one year history of dizziness and gait disturbance. The computerized tomography and MRI of the brain and spinal cord showed tumoral form of mass on cerebellar vermis and roof of the fourth ventricle. The histological study of the partially excised cerebellar mass demonstrated granulomatous reaction around Schistosoma mansoni eggs. After operation, praziquantel was used for 7 days(60 mg/kg/day) drally. This is the first case report of central nervous system Schistosomiasis in Korea.
Adult ; Brain ; Central Nervous System ; Cerebellum ; Dizziness ; Eggs ; Fourth Ventricle ; Gait ; Humans ; Korea ; Magnetic Resonance Imaging ; Neuroschistosomiasis ; Ovum ; Praziquantel ; Schistosoma mansoni ; Schistosomiasis* ; Spinal Cord

There have been some reports on schistosomiasis of school children in Sudan’s Nile River basin area; however, information about the infection status of Schistosoma species and intestinal helminths among village residents of this area is very limited. Urine and stool samples were collected from the 1,138 residents of the Al Hidaib and Khour Ajwal villages of White Nile State, Sudan in 2014. The prevalence of overall schistosomiasis and intestinal helminthiasis was 36.3% and 7.7%, respectively. Egg positive rates were 35.6% for Schistosoma haematobium, 2.6% for S. mansoni, and 1.4% were mixed. The prevalence of schistosomiasis was significantly higher in men (45.6%) than in women (32.0%), in Khou Ajwal villagers (39.4%) than in Al Hidaib villagers (19.2%), and for age groups ≤15 years old (51.5%) than for age groups >15 years old (13.2%). The average number of eggs per 10 ml urine (EP10) of S. haematobium infections was 18.9, with 22.2 eggs in men vs 17.0 in women and 20.4 in Khou Ajwal villagers vs 8.1 in Al Hidaib villagers. In addition to S. mansoni eggs, 4 different species of intestinal helminths were found in the stool, including Hymenolepis nana (6.6%) and H. diminuta (1.0%). Collectively, urinary schistosomiasis is still prevalent among village residents in Sudan’s White Nile River basin and was especially high in men, children ≤15 years, and in the village without a clean water system. H. nana was the most frequently detected intestinal helminths in the 2 villages.
Child ; Eggs ; Female ; Helminthiasis ; Helminths ; Humans ; Hymenolepis nana ; Male ; Ovum ; Prevalence ; Rivers ; Schistosoma ; Schistosoma haematobium ; Schistosoma mansoni ; Schistosomiasis haematobia ; Schistosomiasis ; Sudan ; Water

This study was performed to observe the infection status of sweetfish, caught from Kwangjung-stream and Namdae-stream in Yangyang-gun, Kangwon-do in August 1989, with the metacercariae of Metagonimus yokogawai. All of 28 sweetfish from Kwangjung-stream were infected with the metacercariae of M. yokogawai. The number of metacercariae in a fish ranged 89-521(224 on average), and the number of larvae/g of flesh was 12 approximately 55 (22 on average). On the other hand, no metacercariae were detected in the fish from Namdae-stream. It has been confirmed that the Kwangjung-stream in Yangyang-gun, Kangwon-do is one of the endemic foci of metagonimiasis in Korea.
English-Abstract ; Fish-Diseases-parasitology ; Heterophyidae-isolation-and-purification ; Korea-epidemiology ; Trematode-Infections-parasitology ; *Fish-Diseases-epidemiology ; *Fresh-Water ; *Heterophyidae- ; *Trematode-Infections-epidemiology

This study was performed to observe the infection status of sweetfish, caught from Kwangjung-stream and Namdae-stream in Yangyang-gun, Kangwon-do in August 1989, with the metacercariae of Metagonimus yokogawai. All of 28 sweetfish from Kwangjung-stream were infected with the metacercariae of M. yokogawai. The number of metacercariae in a fish ranged 89-521(224 on average), and the number of larvae/g of flesh was 12 approximately 55 (22 on average). On the other hand, no metacercariae were detected in the fish from Namdae-stream. It has been confirmed that the Kwangjung-stream in Yangyang-gun, Kangwon-do is one of the endemic foci of metagonimiasis in Korea.
English-Abstract ; Fish-Diseases-parasitology ; Heterophyidae-isolation-and-purification ; Korea-epidemiology ; Trematode-Infections-parasitology ; *Fish-Diseases-epidemiology ; *Fresh-Water ; *Heterophyidae- ; *Trematode-Infections-epidemiology