Lecture 04 - Leishmania Flashcards
What causes leishmania
a single celled organism of the genus leishmania belonging to the family trypanosomatidae
What are the reservoires of leishmania
canines, rodents, humans
What is the vector of leishmania
the female sandfly
What is the disease manifestation caused by
partially due to the parasite, but also the presence of an RNA virus in the parasite and the immune response
What is unique about the leishmania life cycle
no sexual stage has been identified
What causes cutaneous or mucocutaneous leishmaniasis
L. major, L. tropica, L. aethiopoca
What caues visceral leishmaniasis
L. donovani, L. infantum
What is the parasitic stage of leishmania in mammals
amastigotes
What is the parasitic stage of leishmania in sanfly
promastigotes
How to leishmania ensure a high level of parasitemia
they form a blockage in the sandfly gut so it doesn’t feel hungry, once there is lots of them the plug breaks, the sandfly feeds and the parasite is transmitted
What are risk factors for leishmania
poor rural housing conditions, poor sanitation, lack of accessible medicines, conflict, HIV
What is the differentiation in the insect form of leishmania
increased surface glycoprotein GP63, flagellated, prefer alkaline pH, prefer high glucose concentration
What is the differentiation in the human form of leishmania
decreased GP63, rudimentary flagella, prefer acid pH, prefer sparse glucose concentration
What is GP63
a zinc proteinase found on the parasite membrane and aids in the internalization of promastigotes
What do parasites use the macrophage for
they bind to the cell and use it as a replication vessel by internalizing, eventually they get too full and the macrophage bursts which causes a type of immunosuppression allowing further spread of infetion
What is LCL
local cutaneous, well defined round painless ulcer with raised edges and a central crust (can develop to a granuloma)
What is DCL
diffuse cutaneous, subcutaneous noduls that do not usually ulcerate
What is disseminated cutaneous
10-300 pleomorphic lesions in >2 sites on the body
What is mucocutaneous
upper respiratory tract mucosa commonly affected, destruction of walls of oral-nasal and pharynfeal cavities
What is visceral
systemic, most severe case, if not treated they die
What is PKDL
post kala-azar disseminated, granulomas that appear after treatment of visceral
What makes leishmania even worse
HIV
Why is it hard to diagnose leishmania
it mimics many things, invasive biopsies are required to get a good sample, molecular techniques are good but not practical in effected areas, antibodies are not always present
What is the treatment of leishmania
cleaning of lesions, treatment of secondary bacterial infections, reconstruction of damaged tissues, antimony compounds
