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

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.

Keywords: Canary Islands; ELISA; IgE antibodies; IgG antibodies; anisakiosis; parasitic infection; seroprevalence; zoonoses.

Figure 1

Mean and standard deviation of IgG and IgE anti-Anisakis antibody levels by sex. Group comparisons were performed using Student’s t-test for normally distributed data and the Mann–Whitney U test for non-normally distributed data.

Figure 2

Mean and standard deviation of IgG and IgE anti-Anisakis antibody levels by age group. Group comparisons were performed using Student’s t-test for normally distributed data and the Mann–Whitney U test for non-normally distributed data. * p < 0.05.

Figure 3

Mean and standard deviation of IgG (B) and IgE (A) anti-Anisakis antibody levels by island (GC: Gran Canaria; T: Tenerife; F: Fuerteventura; L: Lanzarote; LP: La Palma; LG: La Gomera; EH: El Hierro). Group comparisons were performed using Student’s t-test for normally distributed data and the Mann–Whitney U test for non-normally distributed data. Significant differences are described in the text.

Figure 4

Mean and standard deviation of IgG and IgE anti-Anisakis antibody levels by isoclimatic zone: 1, mild temperate (Tm); 2, cold temperate (Tc); 3, dry desert (Dd); 4, dry steppe (Ds). Group comparisons were performed using Student’s t-test for normally distributed data and the Mann–Whitney U test for non-normally distributed data. * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001.