Introduction to Parasites Flashcards
What is a vector
Organism which acts as intermediate host for parasite
Transmits parasite to next host
What are the three classes of parasites?
Protozoa, helminths and ectoparasites
Describe the structure of protozoa
Single celled organisms
What is the mode of protozoa transmission?
Intestinal parasites - fecal - oral route
Blood parasites - arthropod vector
What is the species responsible for malaria?
Plasmodium falciparum
What is the vector for malaria?
Anopheles mosquito
What is the life cycle of malaria?
Sporozoites injected under skin by mosquito,
Travel through blood & enter liver
Mature in the liver
Re-enter the circulation as merozoites
Invade red blood cells, multiply and lyse cells
What is the diagnosis of amoebic dysentery?
Cysts in formed stool - microscopy
Diarrhoea with blood and pus
What type of disease is Amoebic Dysentery responsible for?
Intestinal and extra-intestinal infections
Liver abscess in late disease
What are the different types of helminths?
Nematodes, Cestodes, Trematodes
What are Nematodes?
Round worms
What are Cestodes
Tapeworms
What are trematodes
Flatworms
What is the diagnosis of nematodes?
Press adhesive sellotape against perianal region
Name a type of cestode
Tapeworms (taenia saginata/solium)
What are the various methods of transmission a tapeworm?
Raw/undercooked meat
Where is there a high incidence of Schistosomiasis
Near fresh water, snail is important in the life cycle intermediate host
What accompanies a helminth infection?
Eosinophilia
Elevated IgE
How is diagnosis of a parasite infection achieved?
Microscopy of parasites cysts and ova
Serology - detection of antibodies
Blood films for malaria
Are cultures of parasites possible?
rarely
Schistosomiasis is what kind of parasite?
Flatworm (trematode)
Ascarius lumbricoides is what kind of parasite?
Round worm (nematode)
What kind of parasite infection is leishmaniasis and amoebic dysentry?
Protozoal
What are ectoparasites
Parasites which live outside the body
What can Helminths cause?
Lead to developmental delay in children.
Bowel obstruction can arise
What can pork tapeworms cause?
Cysts to form outside of the gut and cause problems, especially in brain
What can Trematodes cause?
Liver failure and bladder cancer if untreated.
