Onchocerciasis (Onchocerca Volvulus) Infection with Onchocerca volvulus leads to onchocerciasis or river blindness . Onchocerciasis occurs primarily in West Africa but also in Central and East Africa and is the world's 2nd leading infectious cause of blindness. There have been…
Etiology The filarial worms Brugia malayi ( Malayan filariasis ), Brugia timori, and Wuchereria bancrofti ( bancroftian filariasis ) are threadlike nematodes that cause similar infections. Infective larvae are introduced into humans during blood feeding by the mosquito vector. Over…
Etiology Strongyloidiasis is caused by the nematode, or roundworm, Strongyloides stercoralis. Only adult female worms inhabit the small intestine. The nematode reproduces in the human host by parthenogenesis and releases eggs containing mature larvae into the intestinal lumen. Rhabditiform larvae…
Etiology The cause of enterobiasis, or pinworm infection, is Enterobius vermicularis, which is a small (1 cm in length), white, threadlike nematode, or roundworm, that typically inhabits the cecum, appendix, and adjacent areas of the ileum and ascending colon. Gravid females…
Etiology Trichuriasis is caused by the whipworm , Trichuris trichiura, a nematode, or roundworm, that inhabits the cecum and ascending colon. The principal hosts of T. trichiura are humans, who acquire infection by ingesting embryonated, barrel-shaped eggs ( Fig. 319.1…
Etiology Two major genera of hookworms, which are nematodes, or roundworms, infect humans. Necator americanus, the only representative of its genus, is a major anthropophilic hookworm and is the most common cause of human hookworm infection. Hookworms of the genus…
Etiology Ascariasis is caused by the nematode, or roundworm , Ascaris lumbricoides. Adult worms of A. lumbricoides inhabit the lumen of the small intestine. The reproductive potential of Ascaris is prodigious; a gravid female worm produces 200,000 eggs per day.…
Toxoplasma gondii, an obligate, intracellular, apicomplexan protozoan, is acquired perorally, transplacentally, or rarely parenterally in laboratory accidents, transfusions, or from a transplanted organ. In immunologically normal children, acute acquired infection most often is asymptomatic or unrecognized, but may cause lymphadenopathy…
Babesiosis is a malaria-like disease caused by intraerythrocytic protozoa that are transmitted by hard body ( ixodid ) ticks. The clinical manifestations of babesiosis range from subclinical illness to fulminant disease resulting in death. Etiology More than 100 species of…
Malaria is an acute illness characterized by paroxysms of fever, chills, sweats, fatigue, anemia, and splenomegaly. It has played a major role in human history, causing harm to more people than perhaps any other infectious disease. Although substantial progress has…