D3.53 - Prevalence of allergic sensitization to edible insects in exposed breeders from Thailand

Edible insect proteins have emerged as a sustainable alternative to conventional animal proteins. Insects are commonly consumed in Thailand for centuries and, nowadays, more than 20000 sites, mostly small-scale family farms, breed edible insects in the country. However, insects represent major sources of pan-allergens described in seafood or house dust mite (HDM) as well as insect-specific allergenic proteins for humans which trigger food-induced anaphylaxis when ingested or occupational respiratory allergic symptoms by airborne exposures. In this cross-sectional study, we aimed to assess the incidence of allergic sensitization to edible insects in a cohort of insect breeders from different regions of Thailand

A cross-sectional population study was performed involving 104 adult subjects recruited from thirteen sites and breeding at least one of these edible insects: silkworm (Bombyx mori), mealworm (Tenebrio molitor), cricket (Acheta domesticus), locust (Patanga succincta) or black soldier fly (BSF, Hermetia illucens). Each participant answered a self-reported questionnaire about their health and development of food/non-food-induced allergic symptoms. The prevalence of allergic sensitization to these insect species as well as to HDM and shrimp was assessed by ELISA using commercial (for HDM) or in-house prepared protein extracts.

Twelve percent (12/104) of subjects self-reported at least one allergic symptom in relation to occupational exposure to insects, mostly rash and itching (50%). Out of these 12 participants, 4 and 5 self-reported seafood/shrimp or house dust allergy respectively. None reported insect consumption-related allergic symptoms. Of the 104 participants, 23 (22%) exhibited IgE sensitization to at least one insect species. The levels of allergic sensitizations to silkworm, mealworm, BSF, cricket and locust reached 6 (6/104), 17 (18/104), 12 (12/104), 6 (6/104) and 9 (9/104) percent respectively. Of the insect-sensitized individuals, 11 were monosensitized (mostly to mealworm, 64%) whereas polysensitizations to two (3/23), three (4/23) or four (5/23) insect species were also observed. Co-sensitizations to HDM and shrimp were detected in 52 (12/23) and 35 (8/23) percent of insect-sensitized population. However, the patterns of allergen sensitization and the self-report of insect, seafood or house dust were not associated.

Despite the limited sample size of our cohort which precludes strong conclusions. occupational exposure to edible insects in Thai breeders may frequently cause IgE mediated allergic sensitization. The large discrepancy between the levels of allergic sensitizations and the self-reported insect allergy underscores the utility of insect-specific skin testing and allergen challenges to improve the diagnosis of occupational insect allergy. Component-resolved diagnosis using individual pan- and insect-specific allergens could improve the characterization of edible insect allergic sensitization and notably differentiate IgE cross-reactivities from insect-specific allergic sensitizations.