Parasite Flashcards
Define “parasite”?
Animals or plants who live on or in others from which they obtain nutrition
What are the 3 main types of parasite?
Helminths
Protozoa
Arthropods
What is a protozoa?
A microscopic unicellular organism
Can protozoa live independtly?
Protozoa can live free of a host
How do protozoa travel between human hosts?
Those in the human intestine travel there by the faecal-oral route.
Those in the blood/tissue travel there by an arthropod vector.
Can protozoa multiply in humans?
Yes, protozoa multiply in humans
What protozoa causes malaria?
4 plasmodium species
P. Falciparum is the most deadly
What is the vector for the plasmodium species that cause malaria?
Anopheles Mosquito Vector
In what form are plasmodium species injected under the skin by mosquitos?
As sporozoites
How do sporozoites mature?
They travel through blood to liver where they mature into merozoites
What do merozoites do in the body to cause malaria?
Invade & destroy RBCs, using them to multiply
What causes Amoebic Dysentery?
The protozoa: Entamoeba Histolytica
What are the effects of AMoebic Dysentery?
- Protozoal Cysts in stool
- Late disease Liver abscesses
- Diarrhoea with blood/pus
What does Entamoeba Histolytica do to RBCs?
Ingests them by Pseudopodia
What causes Leishmaniasis?
Leishmania Species
What are the sub-types of Leishmaniasis?
Cutaneous & muco-cutaneous
What do the sub-types of leishmaniasis cause?
Skin & mucosal Ulcerations
What does Visceral Leishmaniasis cause?
- Fever
- Weight loss
- Hepato-Splenomegaly
How are Leishmania transmitted?
By Sandfly Bites.
What are 3 types of Helminths?
[Hint: Sellotape & tremors]
Nematodes (Roundworms)
Trematodes (Flatworms)
Cestodes (cellotape)
How do Nematodes reach the Small intestine?
- Eggs ingested & enter Blood
- Egs hatch & enter lungs
- Lungs -> stomach -> Small intestine
What can Nematodes cause?
- A mass of worms can block bile duct
- Loefllers Syndrome (accumulation of eosinophils in lungs)
How are nematodes diagnosed?
Ova are seen in the Stool sample microscopy
How are Trematodes diagnosed?
Ova can be seen in the faeces & urine
How do trematodes hatch?
In fresh water as miracidia
Where do trematodes mature?
In the bodies of snails (intermediate hosts)
What is an adult trematode called?
Cecaria
How trematodes reach the liveR?
Penetrate human skin.
Then migrate from Lungs -> Liver.
At what point to nematodes mature into adult roundworms?
In the stomach before entering the small intestine
