Anti-Anisakis IgE Seroprevalence in the Healthy Croatian Coastal Population and Associated Risk Factors

Abstract

BackgroundThe main objective of the study was to determine the degree of sensitization to Anisakis spp. antigens in healthy coastal population of Dalmatia given the high thermally unprocessed fish intake rate present in this area, suggested as a significant risk factor for anisakiasis. We performed a monocenter, cross-sectional pilot study stratified by geographic area of residence, conducted at the County secondary healthcare provider Medicine-biochemical Laboratory in Split (Croatia), from November 2010 till December 2011, on 500 unpaid volunteer subjects undergoing routine blood analysis and belonging to the south coast of the Adriatic Sea.Methodology/Principal FindingsWe studied the IgE seroprevalence to Anisakis spp. Ani s l and Ani s 7 allergens by indirect ELISA in healthy subjects, which were selected at random in the region of Dalmatia (Southern Croatia), among islands, coastal urban and inland rural populations. In order to detect possible cross-reactivity to other human helminthes, serum samples were tested also for the presence of IgG antibodies to Ascaris lumbricoides and Toxocara canis. The overall and coastal Anisakis seroprevalences for the sampled population were 2% and 2.5%, respectively. The logistic univariate regression analysis confirmed that regarding anti-Anisakis IgE seroprevalence, raw fish intake, daily fish intake, homemade origin of fish dish and occupational contact (professional, artisanal or hobby contact with fishery or fish industry) were risk factors associated to Anisakis spp. sensitization, but neither of the variables was exclusive for a particular seropositive population. Also, a significant difference was observed between seropositive and seronegative subjects that had stated allergy or symptoms associated with allergy (atopic dermatitis, asthma or rhinitis) in their previous history.Conclusions/SignificanceBeing the first in Croatia, our study underlines the necessity of incorporating Anisakis spp. allergens in routine hypersensitivity testing of coastal population.

Travelling with <b><i>Anisakis</i></b> Allergens

“…The presence of such antigenic epitopes may enhance the antigenicity of Ani s 7 relative to that of other Anisakis allergens. Consistent with this hypothesis, in a recent study carried out in Croatia, where Anisakis pegreffii is also prevalent [20,21], all members of a population of 10 positive asymptomatic individuals produced antibodies to Ani s 7, but only 3 presented IgE antibodies to Ani s 1 [22]. The Ani s 7 allergen is now commercially available [23], and the usefulness of different allergen combinations for anti- Anisakis IgE determinations can therefore be tested under field conditions.…”

Seafood Allergy, Toxicity, and Intolerance: A Review

“…Over 90% of Anisakis-induced allergic reactions are reported from Mediterranean countries (Spain, Italy, and coastal Croatia) [88,89] and eastern Asia (Japan, Korea) [90,91] where the consumption of traditionally raw or undercooked seafood is common.…”

“…Allergy to A. simplex is not a classical food-related allergy, because it does not require an atopic predisposition [94,95] Generally, Anisakis allergy has been diagnosed by using SPT and laboratory-based tests and specific Anisakis allergens (Table 5). Allergens Ani s 1 and Ani s 7 have been reported as the best markers for diagnosis of Anisakis infections, particularly in patients that consume home-made raw fish [89,94,96]. Both allergens are highly specific (100%) and sensitive (61.1% and 93.9% for Ani s 1 and Ani s 7, respectively); thus, they were proposed as the gold standard for serodiagnosis of human Anisakis infections [92,96].…”

IgE sensitization to Anisakis pegreffii in Italy: Comparison of two methods for the diagnosis of allergic anisakiasis

“…Anisakis ‐specific IgE sensitization has been extensively reported during recent decades, mainly from Spain, Croatia, Morocco and Italy . However, most of the epidemiological studies used to assess anti‐ Anisakis ‐IgE sensitization and Anisakis allergy have been carried out based on IgE‐ Anisakis reactivity detected by ImmunoCAP (iCAP) . A high level of Anisakis ‐IgE hypersensitivity in Italian fishery products handlers, fishermen and consumers of fish has been also reported using the iCAP methodology .…”

“…17,22 Finally, the allergens Ani s 2 (paramyosin; 97 kDa) and Ani s 3 (tropomyosin; 41 kDa), detected in crude extract (CE) of Anisakis larvae, have been considered as less specific for detecting an "Anisakis allergy". 17 Anisakis-specific IgE sensitization has been extensively reported during recent decades, mainly from Spain, 23 Croatia, 24 Morocco 8 and Italy. 25,26 However, most of the epidemiological studies used to assess anti-Anisakis-IgE sensitization and Anisakis allergy have been carried out based on IgE-Anisakis reactivity detected by ImmunoCAP (iCAP).…”