Protozoa Flashcards
Obligate parasites are
those which have to spend part of their life living a parasitic- host relationship
definitive host
parasite reaches sexual maturity
incidental host
host can be infected but does not play a role in the life cycle
Parasites cause
a huge global burden of sickness and death
Parasites cause diseases
in the poor
Most parasites enter through
vector involvement, broken skin, or the mouth
Helminths refers to parasitic worms
nematodes (roundworm), cestodes (tapeworms), and trematodes (flukes)
Helminth infections cause
huge morbidity, symptoms include abdominal pain,
Challenges of helminths are:
- very good at evading and suppressing immunity,
increases in allergy prevalence have occurred
primarily in westernised societies
The whipworm is
one of the most common helminthic infections
Infection may be
asymptomatic
Larvae can migrate through lungs
causing haemorrage e.t.c
Challenges occurred by protozoal parasites
Infecting hosts and specific host cells,
undergo transmission
gaining nutrients
avoid being killed by the host
cryptosporidium lifecycle
transmission occurs by ingestion of oocysts in contaminated water, proliferation and sexual reproduction in the gut,
it is zoonotic
cryptosporidium succesful life strategy
favourable environmental niche, transmission effective,
Malaria - key facts
causative agent - plasmodium spp (5 infect human)
Anopheles mosquitoes are the definitive host
it is an acute disease
disease occurs during the parasites asexual blood stage cycle
Challenges of intracellular life - plasmodium
ad:
gain nutrients from their host cell,
shielded from the host immune system
host cells are readily available and are accessible
Toxoplasma
incidental hosts can be virtually any mammalian species, definitive hosts are cats, transmission to cats occurs via predation, transmission occurs via ingestion of contaminated faeces or meat containing parasite cysts
Humans can be ingested by contamination via cat faeces
For toxoplasma, in healthy hosts,
initial infection causes mild flu like symptoms, chronic infection is ….
Apicomplexan parasites use
gliding motility to invade host cells
