Table of Contents

Whole Allergen

i71 Mosquito

i71 Mosquito Scientific Information

Type:

Whole Allergen

Display Name:

Mosquito

Allergen code:

i71

Family:

Culicidae

Species:

Aedes aegypti

Route of Exposure:

Injection

Latin Name:

Aedes communis

Other Names:

Yellow fever mosquito

WHO/ICD-11 code:

XM95T4

(ICD-11 is currently under implementation by WHO and the ICD-11 codes displayed in the encyclopedia may not yet be available in all countries)

Summary

Aedes aegypti is one of over 3000 species of mosquito, belonging to the Culicidae family. Females feed primarily on mammals by biting the skin, injecting saliva, and extracting blood. The saliva that is inoculated into the body induces cutaneous, and occasionally systemic, reactions.

Allergen

Nature

Ae. aegypti is a mosquito that requires warm and humid conditions for reproduction (1) and, thus, thrives in tropical and subtropical climates (2).

Global abundance of Ae. aegypti has increased an estimated 9.5% with a further increase of 20–30% anticipated by the end of this century (1). Because Ae. aegypti lays its eggs in water, humans add to larval sites through agriculture, polyculture and urbanization. Ae. aegypti abundance has increased in densely populated urban areas in part because of the availability of potential food (blood meals) and of human-created larval sites.

In addition to being the primary vector of important arboviruses (1), Ae. aegypti induces allergic reactions in sensitized individuals (3). People in tropical and subtropical regions are at higher risk of developing allergic sensitization because of mosquito exposure (4).

Taxonomy

*Taxonomic tree of Aedes aegypti* (2)**
Domain	Eukaryota
Kingdom	Metazoa
Phylum	Arthropoda
Subphylum	Uniramia
Class	Insecta
Order	Diptera
Family	Culicidae
Genus	Aedes.

Tissue

Saliva of the mosquito (3)

Epidemiology

Worldwide distribution

Mosquito allergy occurs worldwide, anywhere where mosquitoes and humans interact, and is common in climates that favor the mosquito life cycle, such as tropical and subtropical regions (4).

Route of Exposure

Main

Injection of mosquito saliva (3).

Clinical Relevance

Ae. aegypti saliva contains more than a hundred proteins, some of which induce cutaneous, and occasionally systemic, reactions in sensitized individuals (3).

Allergens in mosquito saliva can induce both immediate type I hypersensitivity reactions and delayed type 4 hypersensitivity reactions (3). Type I hypersensitivity reactions involve IgE-mediated mast cell degranulation that leads to vasodilation and pruritus within a few minutes of being bitten (3, 5). Wheals and erythema rapidly develop at the site of the bite (5). Delayed type 4 hypersensitivity reactions consist of non-specific infiltrates with macrophages, neutrophils, eosinophils and CD4+/CD8+ T lymphocytes. Delayed reactions are characterized by the appearance of an indurated papule 12–24 hours following the bite, and persisting for several days (5). In rare instances, systemic reactions occur, involving by generalized urticaria, angioedema, wheezing, and anaphylaxis (6).

Molecular Aspects

Allergenic molecules

The three major saliva allergens of Ae. aegypti are Aed a 1–3 (3). Table adapted from Allergome.org (7).

Allergen	Type	Mass (kDa)
Aed a 1	Apyrase	63
Aed a 2	Unknown salivary gland allergen	37
Aed a 3	Unknown salivary gland allergen	29
Aed a 4	Glycosyl hydrolase	66
Aed a 5	Calcium-binding protein	22
Aed a 6	Porin; anion channel protein	30.5
Aed a 7	Unknown	23.5
Aed a 8	Heat Shock protein	72
Aed a 11	Aspartic protease	42

Cross-reactivity

Saliva-derived allergens from mosquitoes can also cross-react with proteins from bees (8).

In a study of individuals with asthma and/or allergic rhinitis in Martinique, cross-reactivity was seen between A. aegypti and mite species; A. aegypti cross reacted with Dermatophagoides pteronyssinus (96.6%), Litopenaeus vannamei (95.4%), Blomia tropicalis (84.4%), and Periplaneta americana (75.4%) (6).

Compiled By

Author: RubyDuke Communications

Reviewer: Dr. Christian Fischer

Last reviewed:April 2022

References

Liu-Helmersson J, Brännström Å, Sewe MO, Semenza JC, Rocklöv J. Estimating Past, Present, and Future Trends in the Global Distribution and Abundance of the Arbovirus Vector Aedes aegypti Under Climate Change Scenarios. Front Public Health. 2019;7:148.
CABI. Aedes aegypti Wallingford, UK2019 [cited 2022 10.01.21]. Available from: https://www.cabi.org/isc/datasheet/94883.
Conway MJ. Type I hypersensitivity promotes Aedes aegypti blood feeding. Scientific Reports. 2021;11(1):14891.
Opasawatchai A, Yolwong W, Thuncharoen W, Inrueangsri N, Itsaradisaikul S, Sasisakulporn C, et al. Novel salivary gland allergens from tropical mosquito species and IgE reactivity in allergic patients. World Allergy Organ J. 2020;13(2):100099.
Hemmer W, Wantke F. Insect hypersensitivity beyond bee and wasp venom allergy. Allergol Select. 2020;4:97-104.
Cantillo JF, Puerta L, Lafosse-Marin S, Subiza JL, Caraballo L, Fernandez-Caldas E. Allergens involved in the cross-reactivity of Aedes aegypti with other arthropods. Ann Allergy Asthma Immunol. 2017;118(6):710-8.
Allergome.org. Mosquito 2021 [cited 2022 10.01.22]. Available from: http://www.allergome.org/script/search_step2.php.
Scala E, Pirrotta L, Uasuf CG, Mistrello G, Amato S, Guerra EC, et al. <b><i>Aedes communis</i></b> Reactivity Is Associated with Bee Venom Hypersensitivity: An in vitro and in vivo Study. International Archives of Allergy and Immunology. 2018;176(2):101-5.