107 - Mosquitoes and Other Blood-Feeding Flies

Abstract

•First Described: Aristotle gave true flies their name “Diptera” (two-winged) in the fourth century BC. In Aristotle’s History of Animals (335 BC), he accurately observed “the diptera have the sting in the front” and “no insect with only two wings has a sting in the rear.” The earliest Diptera appeared in the Triassic period ca. 240 million years ago.•Causes: A variety of blood-feeding flies feed on dogs and cats in North America, including members of the families Culicidae (e.g., mosquitoes), Simuliidae (e.g., black flies), Psychodidae (e.g., sand flies), and Muscidae (e.g., stable flies).•Affected Hosts: Blood-feeding flies feed on a wide variety of reptiles, birds, and mammals, including dogs and cats.•Geographic Distribution: Mosquitoes, black flies, and muscid flies are found on every continent except Antarctica. Sand flies can be found throughout tropical and subtropical Europe, Asia, Africa, and in parts of the Americas.•Primary Mode of Transmission: Fly bites occur upon contact with environments where blood-feeding flies are present. The specific environment of risk varies with each particular fly species.•Major Clinical Signs: Blood-feeding flies cause skin lesions leading to irritation, erythema, pruritus, inflammation, hypersensitivity reactions, and anemia. In addition, blood-feeding flies transmit numerous pathogens as biologic (e.g., Dirofilaria immitis) or mechanical (e.g., anthrax) vectors.•Differential Diagnoses: Skin lesions from other ectoparasites including ticks, mites, fleas, and lice; other cutaneous hypersensitivities (e.g., atopic dermatitis); eosinophilic plaque; autoimmune disorders; photoinduced dermatitis (e.g., solar dermatitis, photosensitive dermatitis).•Human Health Significance: Many species of blood-feeding flies readily feed on humans.