Changes

Stercorarian trypanosomes develop in the '''posterior gut''' of the insect and infective '''metatrypanosomes''' are excreted in the '''faeces''' of the insect onto the '''skin''' of the host.  

Stercorarian trypanosomes develop in the '''posterior gut''' of the insect and infective '''metatrypanosomes''' are excreted in the '''faeces''' of the insect onto the '''skin''' of the host.  

They can then '''penetrate''' the tissues, gaining access through skin abrasions or mucous membranes. The metatrypanosomes then multiply within the reticulo-endothelial system of the host, later '''disseminating''' throughout the organs.  

They can then '''penetrate''' the tissues, gaining access through skin abrasions or mucous membranes. The metatrypanosomes then multiply within the reticulo-endothelial system of the host, later '''disseminating''' throughout the organs invading host cells residing within parasitophorous vacuole. These vacuoles acidify and subsequently release '''trypomastigotes''' into the cell cytoplasm. These then develop into '''amastigotes''' which divide several times eventually transforming back into trypomastigotes that rupture the host cell. From here they may invade other cells or enter the bloodstream where the opportunity may arise to infect the insect vector. The amastigotes may also burst the host cell and invade other cells.

 

'''Trypomastigotes''' then enter the bloodstream and can reinvade new tissues as anastigotes as well as infecting insects during bloodfeeding.

'''''T. cruzi''''', the trypanosome of '''most veterinary importance''', is a typical Stercorarian trypanosome and utilises the '''triatomid “kissing bug”''' as its vector.

'''''T. cruzi''''', the trypanosome of '''most veterinary importance''', is a typical Stercorarian trypanosome and utilises the '''triatomid “kissing bug”''' as its vector.