Interactions between parasites and humans Flashcards
what is a parasite?
an organism that lives on another, at its expense.
what is a helminth?
mutlicellualr, eukaryotic organisms.
what are nematodes?
round worms.
what platyhelminths?
flat worms.
what organs can helminths attack?
all the body’s organisms.
what is direct infection?
-reproductive stages are released, directly infect new host. e.g people drink water with eggs.
what is indirect infection?
- reproductive stages must go through a host.
- e.g. an infected animal is consumed.
what is filarisis?
dysfunction of lymphatic system - therefore often leads to secondary infections.
what is filarisis caused by?
nematodes.
what is filarisis transmitted by?
blood feeding vectors - mosquitos.
what can filarisis cause?
long term tissue damage.
what are protozoans?
unicellular eukaryotes.
what is giardiasis?
- severe diarrhoea
- one of the most common waterborne diseases.
- parasite lives in intestine
what are symptoms of giardiasis?
diarrhoea, greasy (floating) stools.
treatment for giardiasis?
generally self-limiting.
prevention for giardiasis?
good hygiene, avoid contaminated water.
what are kinetoplastids?
- flagellated parasites
- trypanosomes.
What is american trypanosome also called?
chagas disease.
What causes chagas disease?
trypanosoma cruzi
how does chagas disease occur?
animal deposits their faeces into a person’s skin.
what causes african trypanosomiasis?
-caused by trypanosoma brucei.
What is present at the site of the bite?
red sore.
what are effects of T. Brucei?
- effects CNS -seizures.
- can be lethal
What causes leishmaniasis?
-caused by leishamnia spp.
how is leishmaniasis transmitted?
sand-fly bite.
pathogenesis of leishmaniasis?
- cutaneous - invasion of skin tissue
- mucosal - invasion of mucosal tissue.
- visceral - invasion of macrophages in liver.
What causes acomplexa?
toxoplasma gondii.
what causes toxoplasmosis?
undercooked meat, contaminated water, ingeting cat faeces
What are symptoms of toxoplasmosis?
flu like symptoms.
prevention for malaria?
bed nets, insect repellants, doxycycline prophylaxis.
