Protozoa and Disease Flashcards
what is an apicoplast
an organelle similar to a chloroplast
what is the purpose of a cyst
long term survival
what are the three classes of parasitic causing microorganisms
protozoa, helminths, arthropods
what are the WHO list of major parasitic diseases
amoebiasis, hookworm disease, leishmaniasis, schistosomiasis and malaria
what is amoebiasis caused by
entamoeba histolytica - grows in water dirty with fecal matter
what causes hookworm disease
ancylostoma duodenate and necator americanus
what causes leishmaniasis
leishmania via sandfly bite
what causes schistosomiasis
contaminated fresh water by parasitic worms
what causes malaria
anopheles mosquito bite
what microorganism causes malaria
plasmodium genus- bite of female anopheles mosquito
which two diseases outdo malaria for cause of death
aids and tuberculosis
what are the 5 species of plasmodium
- p falciparum
- p vivax
- p ovale
- p malariae
- p knowlesi
describe the malaria transmission cycle
- infection from female anopheles mosquito via sporozoites
- sporozoites form merozoites in liver cells which causes lysis in hepatocytes
- merozoites now get into the blood stream
- RBCs are infected by merozoites
- merozoites form rings in rbc
- trophozoites are hence formed from the rings
- trophozoites multiply to form a schizont and more merozoites - RBCs lyse to release more merozoites into the blood
- schizont may form gametocytes which a different mosquito ingest and hence will transmit the infection
what is the morphology of a P. falciparum trophozoite
headphone shaped or ring shaped
what stain is used for observing malaria infected red blood cells
giemsa stain
what are the general symptoms of malaria
anaemia, splenomegaly (enlarged spleen), fever, nausea, vomiting, rigor, headache, coma
which strain of malaria might cause cerebral malaria
p falciparum
what is a hypnozoite
a dormant protozoa that cna form in p ovale and p vivax strains (these strains have remission and relapse cycles)
how long is the p ovale and p vivax cycle
48hrs
how long is the p malariae cycle
72 hrs
what attracts mosquitos
body odour, skin bacteria, pregnancy
write a short note on chagas disease
caused by trypanosoma cruzi - parasitic protozoa carried by reduviid bug. prevalent in america. may cause swellings and rashes in the body i,e intestinal swelling
write a quick note on babesiosis
caused by babesia microti which is protozoa transmitted by deer tick. it infects RBCs to cause fever and haemolytic anaemia. similar to p falciparum. you’ll see a maltese cross on blood film. immunocompromised and splenectomised people are particularly susceptible to this disease.
explain the cryptosporidium spp infection cycle
- humans ingest thick walled oocyst in contaminated water
- parasites reproduce in the small intestine
- oocysts are released into environment via feces
- water and food contaminated
explain the toxoplasmosis infection cycle
caused by toxoplasma gondii
1. cat ingests a cyst from meat of infected animal
2. unsporulated oocyst passed in faeces
3. sporulated cyst forms and is ingested by humans via infected meat or contact with cats
which groups of people may be severely affected by toxoplasmosis
immunocompromised (HIV or cancer) and pregnancy (lead to abortion or defects)
