In your own word, Compare the pathogenesis of visceral leishmaniasis with Chagas
ID: 189442 • Letter: I
Question
In your own word, Compare the pathogenesis of visceral leishmaniasis with Chagas disease (be specific and answer in complete sentences).
Visceral leishmaniasis is transmitted through the bite of a female sand fly. The sand fly bites the human and injects the promastigote into the blood known as the infection stage. Next promastigotes are phagocytized by the macrophages and transform into amastigotes inside the macrophages. The amastigotes then multiply inside the cells and then is picked up by a sand fly biting the human infected where the amastigotes transform into promastigotes inside the gut of the fly and divide. The process starts all over.
Chagas disease starts with the triatomine bug biting a human and passing the metacyclic trypomastigotes through their feces into the bite wound known as the infection stage. Once inside the host they penetrate cells and turn into amastigotes where they multiply by binary fission. The intracellular amastigotes transform into trypomastigotes and burst the cell entering the blood stream or they can infect other cells and start the transformation to amastigotes all over. Once they enter the blood stream the trypomastigotes can be picked up by another triatomine bug when they bite the human. Once inside the gut of the bug they turn into epimastigotes and multiply before turning back in to metacyclic trypomastigotes. The process starts all over.
Explanation / Answer
Answer=
The pathogenesis of visceral leishmaniasis=The infection begins withwhen the organisms are inoculated into human skin by the bite of the sandfly & are phagocytosed by mononuclear phagocytes.
The organisms reproduce within macrophages ,which rupture & yield a cluster of infected macrophages at the site of inoculation.
From this initial local infection .disease take widely divergent cources depending on the immunological capabilities of the host.
1] Young children & malnourished persons are most susceptible
2]The liver,Spleen and lymph nodes become massively enlarged,as macrophages in these organs fill with proliferating microorganisms.
3]Normal organ architecture is gradually replaced by sheets of parasitised macrophages.
4]Eventually these cells accumulate in other organs ,including heart & kidney,
5]after a month s,a patient with visceral leishmaniasis becomes profoundly cachectic & displays massive splenomegaly.
Pathogenesis of Chagas disease=
1]is an insect borne ,zoonotic infection by the protozoan Trypanosoma cruzi,which causes a systemic infection of human.
2]once the organism enters into the body ,they enter into macrophages& undergoes repeated divisions to form a localized nodular inflammatory lesion,a chagoma.
3]The organisms also invade other sites ,including cardiac myocytes and brain.
4] Within host cells organisms differentiate and divide ,break out & enter the bloodstream,from where they may be passed to the insect vector.
5]progressive destruction of cells at the site of infection -particularly heart ,eosophgus and colon -causes organ dysfunction