Parasites Flashcards
What is a parasite?
Organism that lives in another organism
Gets it’s food at the expense of the host
What are the 3 classes of parasites?
Protozoa
Helminths
Arthropods
Give examples of helminths…
Roundworms
Tapeworms
Flukes
Give examples of protozoa…
Malaria (parasite that causes it)
Amoebae
Flagellates
Give examples of arthropods…
Lice
Ticks
Mites
Name 3 major illnesses caused by protozoa.
Malaria
Amoebic Dysentery
Leishmaniasis
How do protozoa tend to be transmitted?
Fecal-oral route or via an arthropod vector
What are the symptoms associated with malaria?
Fever
Chills
Other flu-like symptoms
Describe the life cycle of malarial parasites…
Sporozoites injected under skin by mosquito
Travel in blood to liver
Mature in liver to merozoites
Re-enter circulation
Invade RBC’s, multiply, lyse, invade more RBC’s
Merozoites produce gametocytes
Gametocytes form taken up by mosquito and sheg: leading to production of sporozoites
Process repeats
A patient has got amoebic dysentery. What symptoms/signs are they likely to present?
Diarrhoea with blood/pus
Intestinal and extra-intestinal infections
Possible liver abscess (in late disease)
How would you identify amoebic dysentery in a stool sample, under a microscope?
Cysts
2 nuclei + chromatoid body
How is leishmaniasis transmitted?
Bites of sandflies
What typical symptoms are there of cutaneous/muco-cutaneous leishmaniasis?
Skin/mucosal ulceration
What health affects are caused by visceral leishmaniasis?
Fever
Weight loss
Hepato-splenomegaly
What is the sellotape test used for?
Pinworm infestation (sellotape shows Ova when looked at under a microscope)
Type of roundworm
Lives up your bum