Trypanosoma cruzi
Trypanosoma cruzi is a Espèce of Protiste parasite about the Trypanosomatida. The species causes diseases, trypanosomiases at the man and the animals in South America. The species is transmitted by the Fèces of Réduve S (bugs of the kind Panstrongylus, Triatoma or Rhodnius)
Life cycle
In the insect vector
The parasite is absorbed by the Réduve when it pricks a victim, human or animal, contaminated by Trypanosoma cruzi in its form Trypomastigote, circulating in the Sang. Once in the Stomach of the animal, T.cruzi develops and multiplies in its form épimastigote. It is then found in the Intestin of the Réduve in its metacyclic form Trypomastigote (form close to the circulating form infecting the man). One finds this last form in the Fèces of the Réduve. A Réduve infected by T.cruzi remains contaminant all its life.It takes approximately 3 weeks between the puncture infecting the animal and the emission of the parasitic first in the Fèces.
Transfer of the insect to the man
When the Réduve spade, it emits at the same time Fèces, infected by T.cruzi . It is while being scraped that the victim is contaminated by the parasite. Indeed, it is while being scraped that it puts in contact the Plaie due to the Piqûre of the Insecte and the Fèces infected.At the man
Inside the Host, the forms Trypomastigote S invade the cells, in which it are differentiated in intracellular forms amastigotes. The Amastigote S multiply by binary fission and are differentiated in Trypomastigotes, then are slackened in the Blood circulation.The trypomastigotes infect the various cells retransforment fabrics and in amastigotes intracellular in the new sites of infection. The clinical signs can result from this infectious cycle.
The circulating forms Trypomastigote S are not retorted (difference with the African trypanosomes ). It there has replication only when the parasite enters another cells or is introduced by a news Réduve.
Other modes of transmission
Trypanosoma cruzi can also be transmitted during the blood transfusions, the transplantations of bodies or the mother to the Fœtus through the Placenta.Pathology
See also: Disease of Chagas
The human Trypanosomiasis American, or Disease of Chagas, is a potentially fatal disease.
The first phase of the Disease, the acute phase is generally asymptomatic and notes itself only by the presence of a swelling located on the level of the site of entry of the parasite in the skin.
The chronic phase generally declares 10 to 20 years after the infection. This phase affects the internal bodies of the cardiac and digestive system (Cœur, esophagus, Côlon, peripheral Nervous system). The people infected generally die of Cardiac failure.
The current therapies consist of cures of Nifurtimox (authorized only in Germany and Argentine) and Benznidazole (sold by Hoffman it Roche under the trade descriptions Rochagan® and Radanil® ) for the acute phase Asymptomatique. There are no effective therapies for the chronic phase.
References
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