Allergic reactions associated with tsetse fly bites.

Area of Science:

• Medical Entomology
• Immunology
• Allergology

Background:

• Allergic reactions to arthropod bites are a growing global health concern.
• Alpha-Gal syndrome (AGS) is an allergy to red meat linked to IgE antibodies against galactose-alpha-1,3-galactose (alpha-Gal), often associated with tick bites.
• The role of other arthropods, including tsetse flies, in AGS development is under investigation.

Purpose of the Study:

• To investigate the potential association between tsetse fly (Glossina spp.) bites and AGS.
• To analyze clinical cases and citizen science data related to tsetse fly bites and allergic reactions.
• To explore the possibility of alpha-Gal production by tsetse flies.

Main Methods:

• Analysis of five case series involving tsetse fly bites, including demographic and clinical data.
• Epitope content analysis by ELISA to assess alpha-Gal production in tsetse flies.
• RT-qPCR to examine galactosyltransferase expression in Ugandan tsetse flies (Glossina fuscipes fuscipes).

Main Results:

• Clinical cases of individuals bitten by tsetse flies in Uganda-Rwanda and other regions presented with varying symptoms.
• Two cases were diagnosed with AGS, and one presented with AGS-consistent symptoms.
• Citizen science data identified individuals with allergic reactions to red meat post-tsetse fly bites and others with local skin reactions.
• Gene expression analysis suggested potential alpha-Gal modification in tsetse flies.

Conclusions:

• Tsetse fly bites may induce allergic anaphylactic reactions and potentially contribute to AGS development.
• Diagnosis and monitoring of AGS should consider factors beyond anti-alpha-Gal IgE levels, including arthropod salivary components and immune biomarkers.