Fleas and Diseases

Abstract

Adult fleas are blood-feeding insects that feed on birds and largely on mammals, acting as parasites and vectors of infectious diseases. Tungiasis is the most well-known direct effect caused by flea parasitism, with the sand flea Tunga penetrans occurring both on domestic and wild animals and also on humans, causing pain, pruritus, and secondary bacterial infection. Bites of some fleas may cause allergic dermatitis on humans and animals. In heavy infestations, the cat flea (Ctenocephalides felis felis) can also cause iron deficiency anemia in young animals. As biological vectors, fleas transmit viral, rickettsial, and bacterial diseases to humans, including bubonic plague, murine typhus, flea-borne spotted fever, bartonellosis, tularemia, and others. They are intermediate hosts for some trypanosomatids (Trypanosoma lewisi), cestodes (Hymenolepis spp., Dipylidium caninum), and filarial worms (Dipetalonema reconditum) between animals or between animals and humans, as well as lodge other monoxenic organisms, such as gregarines, microsporidians, and other flagellates (Leptomonas). Flea control depends on whether the purpose is to control fleas as household pest of animals or humans or to control the transmission of flea-borne diseases. Mechanical (natural) and chemical methods, as well as insect growth regulators (IGRs) or insect development inhibitors (IDI), can be used, applying insecticides to the hosts (pets) or to the indoor and outdoor environments. In case of X. cheopis, rodent control must be preceded or accompanied by the flea control. Concerning T. penetrans, the treatment is the surgical extraction of the embedded fleas; in humans, tetanus immunization is also recommended.