PARASITOLOGY 2 Flashcards
what is DALY ranking?
disability adjusted life years
how many years of healthy life do you lose
measured instead of deaths because those diseases dont usually kill you but they worsen your life conditions
which animal is the deadliest?
the mosquito
what is the name of the parasite that causes malaria?
plasmodium
what is the plasmodium life cycle?
- about 100 sporozoites are injected by the mosquito into the human
- they look for the liver
- after they settle in the liver, they replicate there for about 1 week, depending on the species
- the merozoites start to infect RBC and replicate quickly inside them
- the RBC become sticky and block blood flow, which causes oxygen starvation and the brain dies
- when the merozoites burst out of RBC they become gametocytes which are taken up by mosquitoes to go infect someone else again
what is the species of human african trypanosomiasis?
trypanosome brucei
what is human african trypanosomiasis transmitted by?
transmitted by the tsetse fly
what is the sickness that you get from human african trypanosomiasis?
sleeping sickness
the parasite gets into the CNS and then into the brain
this causes confusion and a coma
you get encephalitis and then you die
why were most of these diseases discovered by military doctors?
because of colonization
what is the history of trypanosomes?
were present long before humans
when south america and africa were one and the same continent there was one species of trypanosome and they might have been infecting dinosaurs (200 million years ago)
after the separation, theres now two separate species for south america and for africa
what is the species of trypanosome that is present in south america?
trypanosome cruzi
what are the morphological differences between T.brucei and T.cruzi?
T.cruzi have much larger mitochondria
this diverged due to evolution over 200 million years
what is the vector for T.cruzi?
a triatomine beetle (assassin bug)
what is the life cycle of T.cruzi?
- triatomine (beetle) infects the human with amastigotes
- the amastigotes go into the muscle
- the muscle cells burst
- the amastigotes go into the blood, become trypomastigotes and continue the cycle
which muscles are preferably affected by T.cruzi?
heart, colon, and eosophagus muscles
how do people die from a T.cruzi infection?
after infection you have a fever for 2 weeks but then youre fine
symptoms take a lot longer to come into effect
you carry the infection for life
eventually, heart muscles give out and you die from heart attack
where are most chagas cases present?
south america
what are the two forms of leishmaniasis?
visceral (50 mil cases): attacks the liver, spleen, bone marrow, causes swelling of those organs and is deadly if not treated
cutaneous (300 mil cases): stays on the skin, not deadly, usually self healing but leaves scars
what is leishmaniasis transmitted by?
transmitted by sand flies
what is the leishmania life cycle?
- a sandfly (2 times smaller than a mosquito) infects you with about 1000 promastigotes
- the promastigotes attack your macrophages
- the promastigotes divide inside of the macrophages and become amastigotes
- the amastigotes are picked up by a sandfly and become promastigotes again
what are the different species that cause the two forms of leishmaniasis?
Leishmania Major = cutaneous
Leishmania Donovani = visceral
the two species have a different genome
how is visceral leishmaniasis treated?
treated with ambisome
only one treatment is needed
melts the membrane of the amastigotes very quickly so that they cannot develop resistance
once you get the disease once and are cured, you develop an immunity for it
what is PKDL?
post kala-azar dermal leishmaniasis
in about 10-25% of individuals treated for visceral leishmaniasis, the parasite moves to the skin and they get PKDL, which causes white patches on their skin
for now there is no confirmation that individuals that have PKDL can infect other people with leishmaniasis
