Anisakidae parasites in frozen fish fillets intended for human consumption

INTRODUCTION

Anisakiasis is a human parasitic disease caused by the consumption of raw fish or shellfish containing larvae of the Anisakidae family. It is currently considered an emerging disease of public health interest.

OBJECTIVE

To identify the presence of larvae of the Anisakidae family in samples of frozen raw fish fillets intended for human consumption in markets in Medellín and its metropolitan area in Antioquia, Colombia.

MATERIALS AND METHODS

A cross-sectional study was carried out, in which larvae of the Anisakidae family were detected and identified in frozen raw fish fillets from three representative markets in Medellín and its metropolitan area. A total of 384 ready for consumption fillets were analyzed (197 sawfish, 137 salmon, 37 tuna, and 13 hake), using the pressing and ultraviolet light method. Taxonomic keys were used to identify the collected parasites and to establish its genus. Conventional PCR and Sanger sequencing was performed to determine the species.

RESULTS

Four larvae were found in 4 of the 384 (1.04%) fillets (CI95% 1.04 ± 1.01%). The species of fish in which the larvae were found was sawfish (Scomberomorus spp.) and the genus and species of the larvae was established as Anisakis pegreffii.

CONCLUSIONS

According to the study, the presence of Anisakis parasites in frozen raw fish fillets in the influence area is evident.

Prevalence and molecular identification of zoonotic Anisakis and Pseudoterranova species in fish destined to human consumption in Chile

Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94-1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23-0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097-0.309) in Chilean hakes, 15% (CI: 0.07-0.26) in snoeks, and 1.7% (CI: 0-0.089) in sea breams. Meanwhile, prevalence of anisakid larvae in internal organs showed highest values for peritoneum (100% and 83.3%) for snoeks and Chilean hakes, respectively, for liver (96.7%) and gonads (86.6%) in Chilean hakes, and for intestine (98.3%) in snoeks. Molecular analysis of collected anisakid L3 unveiled presence of two potentially zoonotic nematode species, i.e., Pseudoterranova cattani and Anisakis pegreffii. P. cattani was found in Chilean hakes and snoeks being the first molecular host species report for Chilean snoeks. Besides, A. pegreffii was also identified in these species being the first molecular report on this regard. These findings are relevant for better understanding of epidemiology of anisakiasis in Chilean coasts and for public health issues considering potential risk of human population due to its culinary preferences in eating raw fish.

Anisákidos y anisakidosis: generalidades y su actualidad en Colombia. Revisión bibliográfica

La anisakidosis es una parasitosis ocasionada por nematodos de la familia Anisakidae, causadapor el consumo de pescado parasitado con larvas infectivas (L3) de estos nematodos. EnEuropa y Asia es un problema de salud pública. Sin embargo, en Colombia y en general enlos países de América del Sur, es poco conocida. El objetivo de este trabajo es presentar unarevisión de las generalidades de los parásitos anisákidos y mostrar la situación actual de estaparasitosis en Colombia. Se realizó una búsqueda estructurada de términos MeSH y DeCS enMEDLINE, Cochrane, Embase, LILACS y Scopus; esta se complementó con otra no estructurada en SciELO y Google Scholar. Se incluye un reporte de caso y seis registros de hospederos. Se describen registros de peces de consumo humano parasitados por Anisakis sp., Anisakis physeteris y Pseudoterranova decipiens para el Océano Pacífico y, los géneros Pseudoterranova y Contracaecum en peces del Océano Atlántico y aguas continentales. Se concluye que la anisakidosis representa un riesgo latente para Colombia, es necesario instaurar legislaciones efectivas para un control eficiente sobre esta parasitosis y educar a la población sobre los cuidados necesarios para el consumo de pescado.

Anisakis Nematodes in Fish and Shellfish- from infection to allergies

Anisakidosis is a zoonotic parasitosis induced by members of the family Anisakidae. The anisakid genera includes Anisakis, Pseudoterranova, Hysterothylacium and Contracaecum. The final definitive hosts of these nematodes are marine mammals with a complex life cycle. These nematode parasites use different crustaceans and fish species as intermediate or paratenic hosts and humans are accidental hosts. Human anisakiasis, the infections caused by members of the genus Anisakis, occurs, when seafoods, particularly fish, contaminated with the infective stage (third stage larvae [L3]) of this parasite, are consumed. Pseudoterranovosis, on the other hand is induced by members of the genus Pseudoterranova. These two genera of anisakids have been implicated in human disease globally. There is a rise in reports of gastro-intestinal infections accompanied by allergic reactions caused by Anisakis simplex and Anisakis pegreffii. This review provides an update on current knowledge on Anisakis as a food-borne parasite with special focus on the increasingly reported diversity of fish and crustacean hosts, allergens and immunological cross-reactivity with invertebrate proteins rendering this parasite a significant public health issue.

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Anisakis, is a foodborne zoonotic parasite.

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Humans are accidental hosts of Anisakis L3 larva.

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Consumption of Anisakis parasite-contaminated seafood causes human anisakiasis.

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Zooplankton (Crustaceans: Krills, Squids, Crayfish) composition in fishing regions contribute to Anisakis parasitosis.

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Anisakis is the parasite with the largest number of registered allergens with the IUIS.