Protozoa Flashcards
what are Protozoa
Single-celled eukaryotic organisms (with nucleus)
can be free-living or parasitic
what are the 5 major groups of protozoa
Flagellates
Amoebae
Sporozoans
Ciliates
Microsporidia
What are flagellates
locomotory organelles that reproduce by binary fission
often intestinal
what are the 5 main examples of flagellates
sleeping sickness
american trypanosomiasis
leishmaniasis
trichomonas vaginalis
giardiasis
what flagellate causes sleeping sickness ?
sleeping sickness = human african trypanosomiasis
Trypanosoma spp
Trypanosoma brucei gambiense = west African milder version
Trypanosoma brucei rhodesiense = S.E African
how is human african trypanosomiasis transmitted?
the bite of an infected tsetse fly
causes a chancre at site (red large sore)
what are the symptoms of human African trypanosomiasis?
initially flu like symptoms
CNS symptoms - personality change, body clock alteration, confusion, seizures
untreated leads to coma and death
can human African trypanosomiasis be diagnosed and treated?
Diagnosed by seeing protozoa on microscopy of blood or CSF
Can be treated by drugs
what other trypanosoma species (a flagellate) causes a major disease, this time in central/South America?
american trypanosomiasis, aka chagas disease
Caused by trypanosoma cruzi
how is American trypanosomiasis spread ?
Spread by triatomine bug faeces, blood, contaminated food
what are the symptoms of American trypanosomiasis (chagas disease)
acute and chronic
acute – flu like and romana sign
chronic – dilated cardiomyopathy, failure , malnutrition, swallowing problems and weight loss as a result of Megaesophagus + Megacolon
what does the romana sign look like
swollen eyelid from faeces in eye
can you treat chagas disease?
Effective treatment for acute phase, but once in the chronic phase can only treat supportively eg pacemakers, antiarrhythmics
example 3 of a flagellate
leishmaniasis
how is it spread?
leishmaniasis is spread by infected sand fly
infected sad fly bite
leishmaniasis has 3 clinical pictures:
Cutaneous and Mucocutaneous, and visceral
describe Cutaneous and Mucocutaneous
Both have ulceration and destruction
Ulcers on face,arms,legs
Mucocutaneous lesions can lead to partial or total destruction of the mucous membranes of the nose, mouth and throat cavities and surrounding tissues. → lead to recurrent bacterial pneumonia + sepsis
no treatment
why does having leishmaniasis lead to social prejudice?
When the ulcers heal, they invariably leave permanent scars, which are often the cause of serious social prejudice.
leishmaniasis has 3 clinical pictures:
Cutaneous and Mucocutaneous, and visceral
describe visceral
Affects internal organs
Aka. black fever
Characterised by irregular bouts of fever, substantial weight loss, swelling of the spleen and liver, and anaemia secondary (which may be serious).
high fatality without treatment
Example 4 of flagellates → trichomonas vaginalis
how is it spread?
Sexually transmitted
Example 4 of flagellates → trichomonas vaginalis
symptoms
Can be asymptomatic, have dysuria and yellow frothy discharge
Example 4 of flagellates → trichomonas vaginalis
treatment
Metronidazole
Example 5 of flagellates → giardiasis
spread
Giardia lamblia
Faeco-oral spread
Example 5 of flagellates → giardiasis
symptoms
diarrhoea, cramps, bloating, flatulence,
Example 5 of flagellates → giardiasis
risk factors
recent travel and childcare workers
Example 5 of flagellates → giardiasis
treatment
metronidazole
what are amoeba ?
class of protozoa
Move by means of flowing cytoplasm and production of pseudopodia
what is the key example of an amoebiasis?
amoebic dysentery
amoebic dysentery
- how is it spread?
Faeco-oral
amoebic dysentery
- epidemiology
Common in poor sanitary conditions/ tropical countries