64 - Human Lice, Bed Bugs, Sand Fleas, Myiasis, and Leeches

Abstract

Human lice are obligatory ectoparasitic insects, spending their entire life on the body of their host and feeding exclusively on blood. Humans are parasitized by the head louse, Pediculus humanus capitis, the body louse, Pediculus humanus humanus, and the pubic louse, Pthirus pubis. Infestation by the head louse is called pediculosis capitis, the body louse, pediculosis corporis, and pubic louse, pediculosis pubis or phthiriasis. The common bed bug, Cimex lectularius, is an obligatorily haematophagous ectoparasitic insect that feeds on a variety of birds and warm-blooded mammals, including bats and humans. It is widely distributed throughout temperate parts of the globe and poses serious economic, psychological, and clinical problems to humans. The sand flea, Tunga penetrans is a haematophagous insect parasite of humans and domestic animals. Tungiasis is a zoonotic ectoparasitosis seen in resource-poor populations throughout Latin America, the Caribbean, and sub-Saharan Africa. Myiasis is the infestation of live human and vertebrate animals with larvae (maggots) of flies from the order Diptera, which feed on the host’s dead or living tissue, liquid body-substance, or ingested food. A higher incidence of myiasis is found in rural zones especially in tropical and sub-tropical areas of Africa and America. Animals are generally the most often infested, but occasionally humans, especially those who are ill and incapacitated can suffer from myiasis. There are approximately 650 known leech species, some living on land and others in salt and freshwater. Although some are predators, most of the leeches are haematophagous. Land leeches live in the vegetation of tropical rainforests and tend to breed near springs, streams, and wells frequented by cattle, horses, and other vertebrates. Leeches, which are used for the treatment of clinical symptoms in humans, are called medicinal leeches.