In Southeast Asia, a total of 59 species of foodborne intestinal flukes have been known to occur in humans. The largest group is the family Heterophyidae, which constitutes 22 species belonging to 9 genera (Centrocestus, Haplorchis, Heterophyes, Heterophyopsis, Metagonimus, Procerovum, Pygidiopsis, Stellantchasmus, and Stictodora). The next is the family Echinostomatidae, which includes 20 species in 8 genera (Artyfechinostomum, Acanthoparyphium, Echinochasmus, Echinoparyphium, Echinostoma, Episthmium, Euparyphium, and Hypoderaeum). The family Plagiorchiidae follows the next containing 5 species in 1 genus (Plagiorchis). The family Lecithodendriidae includes 3 species in 2 genera (Phaneropsolus and Prosthodendrium). In 9 other families, 1 species in 1 genus each is involved; Cathaemaciidae (Cathaemacia), Fasciolidae (Fasciolopsis), Gastrodiscidae (Gastrodiscoides), Gymnophallidae (Gymnophalloides), Microphallidae (Spelotrema), Neodiplostomidae (Neodiplostomum), Paramphistomatidae (Fischoederius), Psilostomidae (Psilorchis), and Strigeidae (Cotylurus). Various types of foods are sources of human infections. They include freshwater fish, brackish water fish, fresh water snails, brackish water snails (including the oyster), amphibians, terrestrial snakes, aquatic insects, and aquatic plants. The reservoir hosts include various species of mammals or birds.The host-parasite relationships have been studied in Metagonimus yokogawai, Echinostoma hortense, Fasciolopsis buski, Neodiplostomum seoulense, and Gymnophalloides seoi; however, the pathogenicity of each parasite species and host mucosal defense mechanisms are yet poorly understood. Clinical aspects of each parasite infection need more clarification. Differential diagnosis by fecal examination is difficult because of morphological similarity of eggs. Praziquantel is effective for most intestinal fluke infections. Continued efforts to understand epidemiological significance of intestinal fluke infections, with detection of further human cases, are required.
Animals ; Asia, Southeastern/epidemiology ; *Food Parasitology ; Humans ; Intestines/*parasitology ; Trematoda/classification/genetics/*isolation & purification/pathogenicity ; Trematode Infections/diagnosis/*epidemiology/*parasitology/therapy

Child, Preschool ; Diagnostic Errors ; Female ; Humans ; Lung Diseases, Parasitic ; diagnosis ; Pericardial Effusion ; diagnosis ; parasitology ; Pleural Effusion ; diagnosis ; parasitology ; Trematode Infections ; diagnosis

A 65-year old Korean man, living in Mokpo-city, Jeollanam-do, Republic of Korea, visited a local clinic complaining of right upper quadrant pain and indigestion. At colonoscopy, he was diagnosed as having a carcinoma of the ascending colon, and thus, a palliative right hemicolectomy was performed. Subsequently, an adult fluke of Gymnophalloides seoi was incidentally found in a surgical pathology specimen of the lymph node around the colon. The worm was found to have invaded gut lymphoid tissue, with characteristic morphologies of a large oral sucker, a small ventral sucker, and a ventral pit surrounded by strong muscle fibers. This is the first reported case of mucosal tissue invasion by G. seoi in the human intestinal tract.
Trematode Infections/diagnosis/parasitology/*pathology ; Trematoda/*isolation & purification/ultrastructure ; Male ; Lymphoid Tissue/*parasitology ; Korea ; Intestinal Diseases, Parasitic/diagnosis/*parasitology/pathology ; Humans ; Colonic Diseases/*parasitology ; Colon/*parasitology/pathology/surgery ; Animals ; Aged

Acanthotrema felis is an intestinal trematode of cats originally reported from the Republic of Korea. Only 1 human case infected with a single adult worm has been previously recorded. In the present study, we report 4 human cases infected with a total of 10 worms recovered after anthelmintic treatment and purging. All 4 patients reside in coastal areas of Jeollanam-do, Korea, and have consumed brackish water fish including the gobies, Acanthogobius flavimanus. The worms averaged 0.47 mm in length and 0.27 mm in width, and had 3 sclerites on the ventrogenital sac; 1 was short and thumb-like, another was long and blunt-ended, and the 3rd was long and broad-tipped. They were identified as A. felis Sohn, Han, & Chai, 2003. Surveys on coastal areas to detect further human cases infected with A. felis are required.
Adult ; Animals ; Antiparasitic Agents/administration & dosage ; Feces/parasitology ; Feeding Behavior ; Humans ; Male ; Microscopy ; Middle Aged ; Praziquantel/administration & dosage ; Republic of Korea ; Trematoda/*isolation & purification ; Trematode Infections/*diagnosis/*parasitology

A 33-year-old Korean man visited a medical clinic with complaints of throat discomfort and pain for one week. The symptoms occurred one day after eating raw brackish water fish, perch. Endoscopy revealed a fluke, about 5 mm in length, attaching to and peristaltically moving on the surface of the mucosa at the arytenoid region of the larynx. Microscopically, the testes were triangular, tandem, and separated by the uterus. The ovary and cirrus pouch were placed apart from median line between testes. Numerous blood cells were observed in the ceca. The worm was identified to be Clinostomum complanatum. This is the second human case of clinostomiasis in Korea.
Adult ; Animal Structures/anatomy & histology ; Animals ; Endoscopy ; Foodborne Diseases/*diagnosis/parasitology ; Humans ; Korea ; Larynx/parasitology/pathology ; Male ; Microscopy ; Pharynx/parasitology/pathology ; Trematoda/anatomy & histology/*isolation & purification ; Trematode Infections/*diagnosis/parasitology

In November 2007, a 46-year-old male Thai patient presented with chronic abdominal pain for over 3 years. Colonoscopy revealed a small parasite of about 2 x 1 mm in size attached to the cecum mucosa. The worm was removed endoscopically, fixed, and stained for morphological observations. The specimen was identified as Anchitrema sanguineum (Digenea: Anchitrematidae), a trematode first reported in a reptile, Chamaeleo vulgaris, from Egypt, and then sporadically found in the intestines of insectivorous bats and other mammals. The patient was treated with praziquantel but no more worms were found in his stool. His symptoms improved slightly but not cured completely. It remains unclear whether the chronic abdominal pain of the patient was caused by this trematode infection. Whatever is the pathogenicity of this trematode, this is the first human case of A. sanguineum infection in the literature.
Abdominal Pain/*etiology ; Animals ; Antiprotozoal Agents/therapeutic use ; Cecum/parasitology ; Colonoscopy ; Humans ; Intestinal Mucosa/parasitology ; Male ; Middle Aged ; Praziquantel/therapeutic use ; Thailand ; Trematoda/*isolation & purification ; Trematode Infections/*diagnosis/drug therapy/pathology