Intro to Parasites Flashcards
Define a parasite
An organisms that lives in another organism (host) and gets its food at expense of the host
Parasitic infection
Cause burden of disease in both the tropics and subtropics as well in the temperature climate
What are the three mains types of parasites?
- protozoa
- helminths (worms)
- arthropods
Describe protozoa parasites and give three examples
One-celled organisms able to amplify in humans.
- Malaria
- Amoebae
- Flagellates
How are protozoa transmitted?
- Fecal-oral route: if they live human’s intestine
- Arthropod vector: if they lie in the blood or tissue in human’s
What parasite causes malaria?
Plasmodium falciparum
Characteristics of malaria
-fever, chills, flu-like symptoms
Life cycle of malaria
- sporozoites injected under skin by mosquito
- Travel through blood to liver
- Mature in liver and enter blood as merozoites
- Invades red cells, multiply and lyse leading to more invasion
- Sexual forms taken up by mosquito and others infected
Methods of malaria control
- Insecticide treated mosquito nets (ITNs)
- prophylaxis
What parasite causes Amoebic Dysentery?
Entamoaeba histolytica
Life cycle of amoebic dysentery
Trophozite ingests red cells by throwing out pseudopodia
Clinical features in Amoebic Dysentery
cysts in stool and liver abscesses
What parasite causes Leishmaniasis (flagellate)?
Bite from sand flies which carry Leishmania spp.
Clinical features in Leishmaniasis (flagellate)
Cutaneous or muco-cutaneous leishmaniasis - mucosal ulceration
Visceral leishmaniasis - fever, weight loss, hepatic-splenomegaly
Three main types of Helminths (worms)
- Nematodes (round worms)
- Cestodes (tapeworms)
- Trematodes (flatworms)