Aetiology and distribution The parasite measures three x 1.5cm. Eggs are released inthe biliary passages and pass to the exterior in the faeces.The miracidium hatches in fresh water and penetrates the tissues of a freshwater snail (Lymnaea species). Soon after acycle lasting four months in the snail, cercariae are released.These encyst on the leaves of watercress and other typesof aquatic vegetation. Humans are infected by eating water cress with encysted metacercariae. Maturation to the adult stage in bile ducts takes about four months until egg laying starts. Sheep are the typical hosts of this infection,and human infections are most likely wherever sheep are herdedin wet pasture lands.
Pathology There is hepatic parenchymal necrosis in the phase of migration by way of the liver. The liver tissue regenerates.The worm burden determines the severity of illness. In the bile ducts there is chronic inflammation, with regenerative hyperplasia of the epithelium and some degree of... [ Continue reading... ]
Another fascinating study is known as, "The clinical importance of magnetic resonance imaging versus computed tomography in malignant pleural mesothelioma." - Lung Cancer. 1998 Dec22(3):215-25 by Knuuttila A, Halme M, Kivisaari L, Kivisaari A, Salo J, Mattson K. Department of Medicine, Helsinki University Central Hospital, Finland. Here is an excerpt: "Abstract - There is no normal therapy for malignant pleural mesothelioma (MPM), but recent reports have shown that extensive surgery combined with chemo - and radiotherapy prolongs the survival of selected patients with early stage disease. This emphasises the need for accurate staging procedures at diagnosis and dependable imaging strategies to assess response to treatment. Computed tomography (CT) of the chest has been the standard imaging strategy for these purposes for the last decade, but it is limited in its capacity to demonstrate accurately the platelike growth pattern of MPM within the thorax due to the partial volume... [ Continue reading... ]
Infection with Trypanosoma gambiense causes an initialfebrile illness which progresses slowly to a chronic phasedominated by infection of the CNS, causing neuronaldeath and a selection of organic neurological syndromes.Neurological involvement occurs early in T. rhodesiense infections, within weeks of inoculation of parasites and,untreated, there is rapid deterioration and death. The twospecies can not be distinguished on morphological grounds.Various species of tsetse fly, Glossina, are the vectors.
Distribution and incidence The specific names of these parasites suggest a WestAfrican (T. gambiense) or East African (T. rhodesiense)origin for the infections, but there is a considerable overlapof the distribution of the two species in Central Africa The total numbers of instances are far fewer thanmalaria, but rhodesiense infections have a considerable economic impact as valuable farming and grazing lands can't be used because of the high risk of infection. Therehave been... [ Continue reading... ]