The infection status of anisakid larvae was examined in 290 marine fish of 25 species and in 108 cephalopods of 3 species purchased in Bayuquan region, Yingko city nearby the coast of the Bohai Sea from may to August 1992. A total of 7,327 larvae were collected from 156 fish of 19 species and 8 squids of one species. The 3rd-stage larvae of Anisakis simplex were collected from 121 fish (63.4%) of 15 species (N = 191) and from 8 squids (14.8%) of one species (N = 54), and they were total, 5,992 (81.8%). Out of remaining 1,335 larvae, 154 (2.1%) were classified as Thynnascaris type B from 23 fish of 4 species, 1,013 (13.8%) as Thynnascaris type C from 79 fish of 13 species. 164 (2.2%) as Hysterothylacium China type V from 20 fish of 4 species, 3 (0.04%) as Raphidascaris from 3 fish of 2 species and one was Pseudoterranova decipiens larva.
Animal ; Anisakiasis/veterinary* ; Anisakiasis/parasitology ; Anisakiasis/epidemiology ; Anisakis/isolation & purification ; Anisakis/classification* ; China ; Fish Diseases/parasitology* ; Fish Diseases/epidemiology ; Fishes ; Larva ; Seawater ; Squid/parasitology*

OBJECTIVEThe aim of this research was to investigate the third phase Anisakis simplex larvae (Anisakis L₃) infection in marine fish caught in Zhoushan Fishery and to find out its physicochemical and biological characteristics.

METHODSA total of 444 fish belonging to 29 species were dissected to isolate anisakis larvae which were then morphologically identified. The survival tolerance of Anisakis L₃ were observed in various conditions, such as in different temperature and medium.

RESULTSA total of 218 fish from 21 species were infected by Anisakis simplex larvae, yielding an overall infection rate of 49.10% (218/444). Trichiurus haumela, pneumatophorus japonicus, miichthys miiuy, argyrosomus argentatus and anguilliformes had high infection rate and had an average infection intensity of 15.28 per fish. 3332 Anisakis larvae were detected in 218 fish, among which Anisakis L₃ and Pseudoterranova larvae accounted for 99.46% (3314/3332) and 0.54% (18/3332) respectively. Anisakis L₃ was highly resistant to common condiment. We found the liquor with high concentration of alcohol showed better insecticidal effect than that with low concentration of alcohol (t = 4.105, P < 0.05) and low concentration mebendazole composite was not only more effective than high concentration mebendazole composite (F = 45.198, P < 0.01) but also more effective than other drugs, such as albendazole and mebendazole. Anisakis L₃ could live up to 9 h and 12 h at -20°C, -10°C respectively, however they were very sensitive to high temperature. It has been shown that they could only survive for less than 11 s and 1 s at 50°C and 60°C respectively.

CONCLUSIONThe observed Anisakis L₃ infection rate in the marine fish found in Zhoushan Fishery was very high. Anisakis L₃ showed high resistance to low temperature but not to high temperature.

Animals ; Anisakiasis ; parasitology ; veterinary ; Anisakis ; Fish Diseases ; parasitology ; physiopathology ; Fisheries ; Fishes ; parasitology ; Larva ; Temperature

The present study was performed to determine the infection status of anisakid larvae in marine fish collected from 3 sea areas of the Republic of Korea. Total 86 marine fish (8 species) collected from the East Sea (Goseong-gun, Gangwon-do), 171 fish (10 species) from the South Sea (Sacheon-si, Gyeongsangnam-do), and 92 fish (7 species) from the Yellow Sea (Incheon Metropolitan City) were examined by both naked eyes and artificial digestion method. Among the total of 349 fish examined, 213 (61.0%) were infected with 8 species of anisakid larvae, i.e., Anisakis simplex, 6 types of Contracaecum spp., and Raphidascaris sp., and the mean larval density was 13.8 per infected fish. Anisakid larvae were detected in 45 fish (52.3%) from the East Sea, 131 fish (76.6%) from the South Sea, and 37 fish (40.2%) from the Yellow Sea. The average numbers of larvae detected were 4.0, 16.6, and 15.9, respectively. Anisakis simplex larvae were detected in 149 fish (42.7%), and the mean larval density was 9.0 per infected fish. They were found in 26 fish (30.2%) collected from the East Sea, 96 fish (56.1%) from the South Sea, and 27 fish (29.3%) from the Yellow Sea. The average numbers of larvae detected were 2.9, 10.3, and 10.5, respectively. Conclusively, the present study suggests that the infection rate and density of anisakid larvae are more or less higher in the fish from the South Sea than those from the East Sea or the Yellow Sea.
Animals ; Anisakiasis/epidemiology/parasitology/*veterinary ; Anisakis/*isolation & purification ; Data Collection ; Fish Diseases/*epidemiology/parasitology ; Fishes ; Larva ; Oceans and Seas ; Republic of Korea/epidemiology

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

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

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

Anisakis spp. (Nematoda: Anisakidae) parasitize a wide range of marine animals, mammals serving as the definitive host and different fish species as intermediate or paratenic hosts. In this study, 18 fish species were investigated for Anisakis infection. Katsuwonus pelamis, Euthynnus affinis, Caranx sp., and Auxis thazard were infected with high prevalence of Anisakis type I, while Cephalopholis cyanostigma and Rastrelliger kanagurta revealed low prevalence. The mean intensity of Anisakis larvae in K. pelamis and A. thazard was 49.7 and 5.6, respectively. A total of 73 Anisakis type I larvae collected from K. pelamis and A. thazard were all identified as Anisakis typica by PCR-RFLP analysis. Five specimens of Anisakis from K. pelamis and 15 specimens from A. thazard were sequenced using ITS1-5.8S-ITS2 region and 6 specimens from A. thazard and 4 specimens from K. pelamis were sequenced in mtDNA cox2 region. Alignments of the samples in the ITS region showed 2 patterns of nucleotides. The first pattern (genotype) of Anisakis from A. thazard had 100% similarity with adult A. typica from dolphins from USA, whereas the second genotype from A. thazard and K. pelamis had 4 base pairs different in ITS1 region with adult A. typica from USA. In the mtDNA cox2 regions, Anisakis type I specimens from A. thazard and K. pelamis showed similarity range from 94% to 99% with A. typica AB517571/DQ116427. The difference of 4 bp nucleotides in ITS1 regions and divergence into 2 subgroups in mtDNA cox2 indicating the existence of A. typica sibling species in the Makassar Strait.
Animals ; Anisakiasis/epidemiology/parasitology/*veterinary ; Anisakis/*isolation & purification ; Cluster Analysis ; DNA Fingerprinting ; DNA, Intergenic/chemistry/genetics ; Fish Diseases/*epidemiology/*parasitology ; Genotype ; Indonesia/epidemiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Prevalence ; RNA, Ribosomal, 5.8S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid