L28: Parasitology Flashcards
What are protozoa
single celled eukaryotes
cell structure similar/different to?
- similar humans and plants (DNA nucleus bound)
- different to bacteria and protozoa
what is special about protozoa transmission
involves more than one species
what causes malaria
plasmodium falciparum
what causes toxoplasmosis
toxoplasma gondii
what causes giardiasis
giardia lamblia
How is giardiasis commonly manifested
food poisoning, indigestion
giardia lamblia infects what?
enterocytes of the small intestine
how is giardia acquired
contaminated water
symptoms of giardia lamblia
watery diarrhoea
what does giardia do?
disrupts projections on enterocytes (vili?), disruption of nutrient absorption
trophozoites
parasites in eating phase
what happens when giardia is in an unfavourable environment
develops cyst wall around itself - protection, survival
life cylce of giardia
cyst swallowed - SI - to LI - cyst formation - shat out
diagnosis and treatment of giardia
- cysts in faeces
- metronizadole
toxoplasma gondii infects
gut of various cat species
what is the mechanism of survival of t. gondii
oocyte/cyst formation - like giardia
how can humans get infected with toxoplamsa gondii
- eating oocytes in cat faeces
- eating uncooked meat
cycle of infection of toxoplasma gondii
infected cat - poop with organism - other organism infected by ingestion of organism - source of infection for next generation (can be rats, sheep - uncooked meat etc)
where does toxoplasma gondii like to reside/multiply
brain
toxoplasmosis how much percent is infected?
30%
when in life is toxoplasma gondii usually caught
childhood
symptoms of toxoplasmosis
- mild, swollen lymph nodes, fever - non specific
HIV relation to toxomplasmosis
untreated HIV can lead to toxoplasma gondii causing brain abcesses
how does toxoplasma gondii affect vision
affect retina, scar tissue, blind spot
Toxoplasmosis diagnosis
- serolology
- IgM = acute infection (new AB, current)
- IgG = chronic infection - PCR for DNA in CSF
- Radiology
- Opthalmoscopy appearances
Toxoplasmosis treatment
usually none for acute
- pregnant or AIDS –> sulphadiazine + pyramethamine
What cuases potentially fatal malaria
plasmodium falciparum
what causes benign malaria
plasmodium vivax
what are the common malaria
plasmodium vivax
plasmodium falciparum
plasmodium falciparium
malaria - potnetially fatal
how is malaria transmitted
mosquitoes
what mosquito transmits malaria
anopheles
life cycle of malaria
mosquito - sucks blood from human - mosquito secretes saliva (anticoagulant) - parasite in glands - infected human - travel through blood - enter liver cells - ultimate target is RBC - exit liver to rbc
malaria causes what symptoms
rigors, fever, shivering, sweating, headache
malaria diagnosis
blood microscopy analysis
P. falciparum differs from P. vivax in terms of RBC
- P. falciparum can infect any circulating RBC - high % infected RBC - severe disease
- P. vivax only infect immature/young RBC - small % infected RBC - mild disease
P. falciparum infected RBC - consequence on capillary
surface of RBC gets chancges, expression of molecules, stick to capillary cells - clump up and block cappillaries - affect brain and kidney perfusion
- sequesteration?
