The Role of Common Housefly as a Mechanical Vector of Pathogenic Microorganisms

Abstract

The common housefly with the scientific name Musca domestica is a common pest of man known to cause nuisance, annoyance and has also been discovered to mechanically transport pathogenic microorganisms to man. Housefly is able to transmit disease to man because of its close association with man. Houseflies feed on liquid or semi-liquid food and therefore when they land on human solid food, they regurgitate liquid containing saliva and digestive juices which may contain pathogens accumulated in their esophagus from their previous feast on rotting and decaying matter such as human and animal feces. Structurally, the housefly is well suited in picking up pathogens. Housefly possesses wings therefore the continuous movement of house flies from filthy substances, such as human feces, animal excreta, carcasses, and garbage, to food makes them perfect candidate vectors for disease transmission. Several studies have shown that eggs of Ascaris lumbricoides, Trichuris trichiura, hookworm, Enterobious vermicularis, Taenia species, Hymenolepis nana, Toxocara canis, and Strongyloides stercoralis are transmitted by houseflies. Protozoan cysts and trophozoites such as Entamoeba histolytica, Giardia lamblia and bacteria such as Shigella species are also transmitted by houseflies. Houseflies can be controlled by various mechanisms which can be cultural, biological or by chemical means.