Introduction to Parasites Flashcards
Define a parasite.
Organism that lives in another organism (host) and gets its food at the expense of this host.
Are parasites simple organisms?
Yes
Are parasites less complex than bacteria?
No
What parasite causes the most deaths globally?
Malaria
What are the three types of protozoa?
Malaria
Amoebae
Flagellates
What are the three types of helminths?
Roundworms
Tapeworms
Flukes
What are the three types of arthropods?
Lice
Ticks
Mites
In what two ways can protozoa live?
Free-living
Parasitic
Where do protozoa multiply?
In humans
How are protozoa transmitted from humans intestine?
Faecal-oral
How are protozoa transmitted from blood or tissue of humans?
Arthropod vector
What type of disease is malaria?
Mosquito-borne.
What are three symptoms of malaria?
Fever
Chills
Flu like illness
What is the parasite involved in malaria?
Plasmodium species (4)
What parasite has the highest mortality in malaria?
Plasmodium falciparum
What type of mosquito acts as the vector?
Anopheles
What type of stained blood film is used to show infected red cells?
Giemsa
What are the two types of malaria blood films?
Thick
Thin
What are injected under the skin by mosquitos and where do they travel to?
Sporozoites
Through blood to liver
What do sporozoites do in the liver and what do they re-enter circulation as?
Mature
Merozoites
What form of parasite is taken up by the mosquito?
Sexual
What 2 things can be used for malaria control?
Insecticide treated mosquito nets
Prophylaxis
What does amoebic dysentery cause?
Diarrhoea with blood/pus
What is the parasite that causes amoebic dysentery?
Entamoeba histolytica
What ingests red cells and how does it do this?
Trophozoite
Throw out pseudopodia
What can be seen under the microscope in amoebic dysentery?
Cysts in a stool sample
What is the parasite that causes Leishmaniasis?
Leishmania species
What are the two main parasites that cause Leishmaniasis?
Cutaneous
Mucocutaenous Leishmaniasis
What type of worm is a nematode?
Round worm
What type of worm is a cestodes?
Tapeworm
What type of worm is a trematode?
Flatworm
What is the other name for pinworm?
Enterobiasis
How is pinworm diagnoses?
Press adhesive sellotape against perianal region in the morning.
See ova on microscopy.
What is the most prevalent nematode?
Ascaris lumbricoides
In ascaris lumbricoides, where do the ingested eggs hatch?
In the intestine
Where is larvae of ascaris lumbricoides carried?
Lungs where it is swallowed again.
What can a mass of ascaris lumbricoides do?
Obstruct the small intestine or common bile duct.
What type of tapeworm is found in beef and pork?
Taenia Saginata
Taenia Solium
What is the intermediate host in tapeworm diseases?
Meat
What is the definitive host in tapeworm diseases?
Human
What is cysticercosis?
Ingestion of taenia solium eggs.
What type of tapeworm is carried by dogs and wolves?
Echinococcus sp.
How is echinococcus sp. transmitted?
Humans ingest eggs which hatch and form a hydatid cyst in the liver.
How is echinococcus sp. removed from the body?
Surgical resection.
What is the biggest trematode disease?
Schistosomiasis
What are the 3 major schistosomes?
Haemoatobium (bladder)
Mansoni (intestines)
Japonicum (intestines)
Where is there a high rate of schistosomiasis?
Near fresh water as snails are needed for transmission.
What is found in fresh water which goes into snails?
Miracidia
What emerges from snails 4-6 weeks later?
Cercaria
What happens after cercaria is penetrated through the human skin?
Migrates through lungs to liver where they mature into worms/
What do schistosome eggs cause?
Inflammation and potentially Katayama fever.
What 2 things is helminth infection often accompanied by?
Eosinophilia
Elevated IgE
What is needed for a definitive diagnosis in parasitology?
Identification of parasite.
What 3 ways can be used to diagnose parasites?
Microscopy (PCO)
Blood films (Malaria)
Serology
