Vector borne protozoa Flashcards
how can malaria spread directly between humans?
via blood transfusions (done by mosquitos in small amounts)
what are the 5 ways in which protozoa can transmit disease?
- vectors (malaria)
- ingestion (Giardia)
- sexual contact (Trichomonas vaginalis)
- transovarial (Babesia bovis)
- placental (Toxoplasma gondii)
the symptoms of protozoan disease is caused by?
- protozoa damaging host tissue
- toxic protozoal products
- immune response to protozoans
- REPRODUCE AND RUPTURE HOST CELLS (Plasmodium spp.)
- ATTACH TO MACROPHAGES, BECOME PHAGOCYTOSED (Toxoplasma gondii)
- ATTACH TO HOST CELL AND DIGEST CONTENTS (Giardia)
what are the two bacteria that cause sleeping sickness?
T.brucei gambiense and T. brucei rhodesiense
which bacteria causes Chagas disease?
Trypanosoma cruzi
what is responsible for spreading trypanosomiasis?
Tsetse flies
where are Tsetse flies found & O where is Trypanosomiasis most common?
- forest
- near dense dhrubs
- rivers and watering holes
- close to human settlements
how can we limit Tsetse fly contact with humans?
tsetse fly traps
what are the symptoms of sleeping sickness?
- swollen lymph nodes
- swelling of face and hands
- skin rash
- fever & severe headaches
- muscle and joint pain
- fatigue
COMA if parasites cross CHOROID PLEXUS to brain and CSF
what are the symptoms of African Trypanosomiasis (sleeping sickness) if it PROGRESSES?
- weight loss
- neurological impairment
where does asexual reproduction occur of Trypanosoma brucei?
in humans
what is the treatment for sleeping sickness? problems?
1st stage: Suramin, Pentamidine 2nd stage: Melarsoprol, Eflornithine - scarce - difficult to administer - HARMFUL side effects
how do treatments for sleeping sickness work?
bind to components that protect PARASITES from OXIDATIVE DAMAGE
is there a vaccine for sleeping sickness?
nope
what does the drug Suramin target in sleeping sickness?
targets GLYCOSOME
how is the GLYCOSOME targeted by drugs against sleeping sickness?
Glycosome is the site of the 1st stages of glycolysis
- enzymes involved in the generation of ATP are confined here
- Suramin binds to the ENZYMES req for ATP synthesis
- O ATP synthesis slows
where is Chagas disease usually found?
all Americas (esp South)
which vector is important in the spread of Trypanosoma. cruzi?
Reduviid insects
what are the 2 stages of Chagas disease (Trypanosoma cruzi) ? symptoms
ACUTE stage- shortly after infection
- swelling at site of infection
CHRONIC stage- after asymptomatic stage (up to several years)
- cardiac symptoms
- digestive damage
- peripheral nervous involvement
DAMAGED MYOFIBRES replaced by FIBROUS TISSUE
describe the pathogenesis of Chagas disease (Trypanosoma cruzi)
- inflammation
- autoimmunity
- antigen variation
in patients with Chagas disease (Trypanosoma cruzi) , where are the parasites found?
in cerebral spinal fluid
how is Chagas disease (Trypanosoma cruzi) prevented?
- spray insecticide
- insecticide paints
- housing improvement
- health education
- PREVENT INFECTED BLOOD TRANSFUSIONS
Leishmaniasis is caused by what?
Leishmania sp. (L. donovani)
describe Leishmania sp. (L. donovan
obligate intracellular parasite
what transmits L. donovani?
female sandflies
who is at risk of Leishmaniasis?
- those in endemic areas
- TIMING: biting at dusk or dawn
what are the 3 ways Leishmaniasis can manifest?
1) cutaneous (skin)
2) mucocutaneous (deep skin/tissue)
3) visceral (internal organ)
describe the clinical presentation of cutaneous leishmaniasis?
- one or more sores after bite
- sores can last weeks–> years
- raised edges and central crater
describe the clinical presentation of mucocutaneous leishmaniasis?
how is inflammation brought about?
- can occur months–>years after initial cutaneous lesion healed
- scanty presence of parasites
- affects NASO-PHARANGEAL tissues
INFLAMMATION: non-specific granulation tissue
what are the symptoms of visceral leishmaniasis?
what happens if it is not treated?
- fever
- weight loss
- enlargement of spleen/liver
- anaemia
NO TREATMENT? fatal
how can Leishmaniasis be prevented?
- no vaccines BUT- protective clothing & insect repellent - PERMETHRIN impregnated clothing - bed nets - PERMETHRIN impregnated bed nets