Anisakiasis is a zoonotic disease induced by anisakid nematodes, and endoscopic inspection is used for a diagnosis or remedy for it. Anisakis simplex, Anisakis physeteris, and Pseudoterranova decipiens had been reported to be the major species causing human infections, particularly, in Japan. However, in Korea, recent studies strongly suggested that Anisakis pegreffii is the major species of human infections. To support this suggestion, we collected anisakid larvae (n=20) from 20 human patients who were undergone gastrointestinal endoscopy at a health check-up center in Korea, and molecular identification was performed on the larvae using PCR-RFLP analysis and gene sequencing of rDNA ITS regions and mtDNA cox2. In addition, anisakid larvae (n=53) collected from the sea eel (Astroconger myriaster) were also examined for comparison with those extracted from humans. The results showed that all human samples (100%) were identified as A. pegreffii, whereas 90.7% of the samples from the sea eel were A. pegreffii with the remaining 9.3% being Hysterothylacium aduncum. Our study confirmed that A. pegreffii is the predominant species causing human anisakiasis in Korea, and this seems to be due to the predominance of this larval type in the fish (sea eels) popularly consumed by the Korean people. The possibility of human infection with H. aduncum in Korea is also suggested.
Anisakiasis ; Anisakis ; Diagnosis ; DNA, Mitochondrial ; DNA, Ribosomal ; Eels ; Endoscopy, Gastrointestinal ; Humans ; Japan ; Korea ; Larva ; Zoonoses

Anisakidosis is a term that collectively refers to a human infection caused by larvae of the family Anisakidae. Because Anisakis simplex was the main cause, it was originally called anisakiasis or anisakiosis, but since other parasites such as Pseudoterranova decipiens also cause similar diseases, the family name is now used as the diagnostic name. Anisakidosis cases have been increasing steadily owing to the propagation of the Japanese raw-fish-eating culture, such as sushi and sashimi, around the world; the traditional raw-fish-eating habits of individual countries; the establishment of marine mammal protection laws; and the development of endoscopic diagnostic techniques. The disease continues to occur in Korea, where most human parasites are believed to have been eradicated and is probably the most common parasitic disease encountered in clinical practice. Anisakidosis is a disease associated with acute abdominal pain. Anisakid larvae can invade the entire digestive tract and abdominal cavity and cause abdominal pain and a variety of digestive system symptoms. Thus, the history of eating raw fish is very important for its differential diagnosis. The lack of a precise understanding of the pathogenesis and clinical course of this disease may lead to unnecessary surgery. Anisakidosis may also manifest as allergic symptoms. Therefore, it is necessary to understand anisakidosis from the perspective of public health, food hygiene, and preventive medicine.
Abdominal Cavity ; Abdominal Pain ; Anisakiasis ; Anisakis ; Asian Continental Ancestry Group ; Diagnosis, Differential ; Digestive System ; Eating ; Food Hypersensitivity ; Gastrointestinal Tract ; Host-Parasite Interactions ; Humans ; Hygiene ; Jurisprudence ; Korea ; Larva ; Mammals ; Parasites ; Parasitic Diseases ; Preventive Medicine ; Public Health ; Raw Foods ; Unnecessary Procedures

Anisakiasis (anisakidosis) refers to a foodborne zoonosis caused by ingesting raw or undercooked marine fish or cephalopods infected with anisakid larvae. The present study was performed to investigate the prevalence of anisakid larvae in anchovies (Engraulis japonica) purchased from 2 local markets in Gyeongsangnam-do, the Republic of Korea (=Korea), during 2018–2019. Anchovies were transported to our laboratory and examined by pepsin-HCl artificial digestion technique followed by microscopic observations and molecular analyses. The overall prevalence of anisakid larvae was 19.5% (39/200), from which a total of 51 larvae (av. 1.3 larvae/infected anchovy) were recovered. Sequencing of the larvae targeting the ITS region, including ITS1, 5.8S rRNA, and ITS2 genes confirmed the species of larvae as Anisakis pegreffii (54.9%; 28/51), Hysterothylacium sinense (23.5%; 12/51), and Hysterothylacium aduncum (21.5%; 11/51). The results suggested that anchovies could be a potential source of human anisakiasis in Korea.
Anisakiasis ; Anisakis ; Cephalopoda ; Digestion ; Gyeongsangnam-do ; Humans ; Korea ; Larva ; Prevalence ; Republic of Korea

Along with globalization of traveling and trading, fish-borne nematodiases seems to be increasing in number. However, apart from occasional and sporadic case reports or mini-reviews of particular diseases in particular countries, an overview of fish-borne nematodiasis among travelers have never been performed. In this review, we gathered fish-borne nematodiasis among travelers for recent 25 years by an extensive global literature survey using appropriate keywords, e.g. travelers diseases, human infection, anisakiasis, gnathostomiasis, capillariasis, sushi, sashimi, ceviche, Gnathostoma, Pseudoterranova, Anisakis, Capillaria, etc., as well as various combinations of these key words. The Internet search engines PubMed, Medline, Google and Googler Scholar were used as much as possible, and the references of every paper were checked in order to identify useful and reliable publications. The results showed unexpectedly high incidence of gnathostomiasis and low incidence of anisakidosis. The different incidence values of the infection with several fish-borne zoonotic nematode species are discussed, as well as some epidemiological aspects of the infections. The difficulties of differential diagnosis in non-endemic countries are emphasized. It is concluded that travelers must avoid risky behaviors which can lead to infection and that physicians and health authorities must advice travelers on the risks of eating behaviors during travel.
Anisakiasis ; Anisakis ; Capillaria ; Diagnosis, Differential ; Feeding Behavior ; Gnathostoma ; Gnathostomiasis ; Humans ; Incidence ; Internationality ; Internet ; Public Health ; Search Engine

Anisakis is a parasite with life cycles involving fish and marine mammals. Human infection, anisakiasis, occurs with the ingestion of raw infected seafood and usually presents with acute or chronic gastrointestinal symptoms from esophageal or gastric invasion. We report a rare caseinvolving the oral cavity. A 39-year-old male presented with oral and sub-sternal pain of one day duration after eating raw cuttlefish. Physical examination revealed areas of erythema and edema with a central white foreign particle on the labial and buccal mucosa. With microscopic field we could remove the foreign material from the lesions. The foreign material was confirmed to be Anisakis. Anisakis was also removed from the esophagus by esophagogastroduodenoscopy. The patient was discharged the following day without complication. Anisakiasis is frequently reported in Korea and Japan, countries where raw seafood ingestion is popular. The symptoms of acute anisakiasis include pain, nausea, and vomiting and usually begin 2–12 hours after ingestion. The differential diagnosis includes food poisoning, acute gastritis, and acute pancreatitis. A history of raw seafood ingestion is important to the diagnosis of anisakiasis. Treatment is complete removal of the Anisakis to relieve acute symptoms and prevent chronic granulomatous inflammation.
Adult ; Anisakiasis* ; Anisakis ; Decapodiformes ; Diagnosis ; Diagnosis, Differential ; Eating ; Edema ; Endoscopy, Digestive System ; Erythema ; Esophagus ; Foodborne Diseases ; Gastritis ; Humans ; Inflammation ; Japan ; Korea ; Life Cycle Stages ; Male ; Mammals ; Mouth ; Mouth Mucosa* ; Nausea ; Pancreatitis ; Parasites ; Physical Examination ; Seafood ; Vomiting

Subepithelial tumors are frequently found in asymptomatic patients in Japan and Korea where cancer screening tests routinely include endoscopy. Most lesions are asymptomatic and clinically insignificant. However, carcinoid tumors, lymphomas, glomus tumor and gastrointestinal stromal tumors (GISTs) are malignant or have the potential to become malignant. Inflammation due to parasitic infestation by Anisakis and poorly differentiated adenocarcinomas in the stomach rarely present as subepithelial lesions. In contrast to the frequency of gastric GIST in the gastrointestinal system, they are uncommon in the duodenum and very rare in the esophagus. The prognosis of patients with GISTs in the stomach is relatively good compared with GISTs in other organs. Along with the location of the tumor, its size and mitotic count are major factors that determine the malignant potential of GIST. Small (<2 cm) asymptomatic GISTs usually have benign clinical course. GIST is the most common subepithelial tumor to occur in the stomach. Although various methods are employed to diagnose GISTs, the risk of GIST metastasis cannot be accurately predicted before lesions are completely resected. Recently, new endoscopic diagnostic methods and treatment techniques have been developed that allow the diagnosis and resection of lesions located in the muscularis propria, without any complications. These endoscopic methods have different indications depending on regions where they are performed.
Adenocarcinoma ; Anisakis ; Carcinoid Tumor ; Diagnosis ; Duodenum ; Early Detection of Cancer ; Endoscopy ; Endosonography ; Esophagus ; Gastrointestinal Stromal Tumors ; Glomus Tumor ; Humans ; Inflammation ; Japan ; Korea ; Lymphoma ; Neoplasm Metastasis ; Prognosis ; Stomach ; Stomach Neoplasms

Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.
Animals ; Anisakiasis/parasitology/*veterinary ; Anisakis/classification/genetics/*isolation & purification ; DNA, Helminth/genetics ; DNA, Ribosomal Spacer/genetics ; *Eels/growth & development ; Fish Diseases/*parasitology ; Larva/classification/genetics ; Phylogeny ; Polymorphism, Restriction Fragment Length ; Republic of Korea

The present study was performed to report 15 anisakiasis cases in Korea and to review the Korean cases reported in the literature. Total 32 Anisakis type I larvae were detected in the stomach of 15 patients by the endoscopy. Single worm was detected from 12 cases, and even 9 larvae were found from 2 cases. Epigastric pain was most commonly manifested in almost all cases, and hemoptysis and hematemesis were seen in 1 case each. Symptom manifestations began at 10-12 hr after eating fish in 73.3% cases. Endoscopy was performed 1-2 days after the symptom onset in most cases. The common conger, Conger myriaster, was the probable infection source in 7 cases. In the review of Korean anisakiasis cases, thus far, total 645 cases have been reported in 64 articles. Anisakis type I larva was the most frequently detected (81.3%). The favorable infection site of larvae was the stomach (82.4%). The common conger was the most probable source of human infections (38.6%). Among the total 404 cases which revealed the age and sex of patients, 185 (45.8%) were males, and the remaining 219 (54.2%) were female patients. The age prevalence was the highest in forties (34.7%). The seasonal prevalence was highest in winter (38.8%). By the present study, 15 cases of gastric anisakiasis are added as Korean cases, and some epidemiological characteristics of Korean anisakiasis were clarified.
Adult ; Animals ; Anisakiasis/epidemiology/*parasitology/*veterinary ; Anisakis/genetics/*isolation & purification/physiology ; Female ; Fish Diseases/*parasitology ; Fishes/classification/parasitology ; Food Contamination/analysis ; Humans ; Larva/genetics/*physiology ; Male ; Middle Aged ; Prevalence ; Republic of Korea/epidemiology ; Stomach/parasitology ; Stomach Diseases/epidemiology/*parasitology

Anisakiasis, a human infection of Anisakis L3 larvae, is one of the common foodborne parasitic diseases in Korea. Studies on the identification of anisakid larvae have been performed in the country, but most of them have been focused on morphological identification of the larvae. In this study, we analyzed the molecular characteristics of 174 Anisakis type I larvae collected from 10 species of fish caught in 3 different sea areas in Korea. PCR-RFLP and sequence analyses of rDNA ITS and mtDNA cox1 revealed that the larvae showed interesting distribution patterns depending on fish species and geographical locations. Anisakis pegreffii was predominant in fish from the Yellow Sea and the South Sea. Meanwhile, both A. pegreffii and A. simplex sensu stricto (A. simplex s.str.) larvae were identified in fish from the East Sea, depending on fish species infected. These results suggested that A. pegreffii was primarily distributed in a diverse species of fish in 3 sea areas around Korea, but A. simplex s.str. was dominantly identified in Oncorhynchus spp. in the East Sea.
Animals ; Anisakiasis/parasitology/*veterinary ; Anisakis/*classification/genetics/*isolation & purification ; Aquatic Organisms ; Cluster Analysis ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Electron Transport Complex IV/genetics ; Fish Diseases/*parasitology ; Fishes ; Korea ; Larva/classification/genetics ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sequence Analysis, DNA

Gastric anisakiasis is a parasitic disease caused by the gastric mucosal penetration of the Anisakis larvae ingested with raw fish. Acute gastric anisakiasis is diagnosed by the endoscopic visualization of Anisakis larvae along with mucosal edema, erythema, hemorrhage, and/or an ulcer, whereas chronic anisakiasis is often observed as a localized tumor commonly occurring in the submucosal layer, and is characterized by eosinophilic granuloma with edema and embedded Anisakis larvae on pathological examination of surgical specimens. We report here a case of chronic gastric anisakiasis provoking a bleeding gastric ulcer, which is a rare clinical manifestation of this condition.
Anisakiasis* ; Anisakis ; Edema ; Eosinophilic Granuloma ; Erythema ; Hemorrhage* ; Larva ; Parasitic Diseases ; Stomach ; Stomach Ulcer* ; Ulcer