Seroprevalence of IgG and IgE Antibodies Against Anisakis in the Presumably Healthy Population of the Canary Islands

TL;DR

This study measures how common Anisakis infections are in the Canary Islands by checking for antibodies in blood samples.

Contribution

The study provides new seroprevalence data for Anisakis in a presumably healthy population across the Canary Islands.

Findings

16.9% of samples showed IgG antibodies, indicating past exposure to Anisakis.

6.8% of samples showed IgE antibodies, suggesting allergic responses to Anisakis.

Older individuals and those in temperate zones had higher antibody prevalence.

Abstract

Food-borne zoonoses, particularly anisakiosis caused by Anisakis spp., are an increasing public health concern due to the rising consumption of raw fish. Anisakiosis results from the ingestion of third-stage larvae of Anisakidae nematodes, with the genus Anisakis re-sponsible for approximately 97% of human cases. While regulatory protocols exist to minimize infection risk in commercial settings, domestic food preparation often lacks such safeguards, creating a gap in public health protection. In the Canary Islands, a major Spanish aquaculture region, farmed fish exhibit a low Anisakis prevalence, suggesting minimal risk from aquaculture products. In contrast, wild-caught fish demonstrate varia-ble parasitism, with recent studies reporting a 25% prevalence among commercial species. Methods: This study assessed Anisakis exposure in the Canary Islands by measuring specific IgG and IgE antibodies in 1043 serum samples collected from all seven islands between March 2014 and October 2015. ELISA assays detected anti-Anisakis antibodies, and the results were analyzed by age, sex, island, and isoclimatic zone. Results: Overall, 16.9% of samples were IgG-positive and 6.8% were IgE-positive. Seroprevalence was significantly higher in indi-viduals aged 60 years and above. Geographic heterogeneity was notable: La Palma had the highest IgG seroprevalence (35.3%), while El Hierro showed the highest IgE prevalence (16.3%). Temperate isoclimatic zones exhibited higher antibody prevalence than dry zones. These findings indicate variable Anisakis exposure across the Canary Islands, likely influenced by environmental and behavioral factors. Conclusions: The results highlight the need for targeted public health interventions to reduce the anisakiosis risk, particularly in regions and populations with elevated exposure.

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