Protozoa Flashcards
What are protozoa?
One celled animals, single cell with nucleus (eukaryotic)
Classification by shape: 5 major groups
Flagellates, Amoebae, Sporozoa, Microsporidia, Cilliates
Example of flagellate
African Trypanosomiasis (sleeping bite)
What are symptoms of African Trypanosomiasis?
Chancre (painless ulcer), flu-like symptoms, CNS involvement (sleepy, confusion, personality change)
American Trypanosomiasis “Chagas Disease”
Spread by triatomine, it defecates, you itch/rub it in, gets into bloodstream.
Symptoms of Amreican Trypanosomiasis
Acute: flu-like symptoms
Chronic (can lie dormant and reo-activate): Cardiomyopathy, Megaoesophagus, Megacolon
Leishmaniasis is spread by…
the sandfly
Leishmaniasis can cause 3 different clinical pictures:
Cutaneous (ulcer at site of bite, scarring)
Mucocutaneous (ulceration and destruction of mucous membranes)
Visceral (replication occurs in spleen, splenomegaly, hepatomegaly, anaemia, weight loss, fever)
Trichomonas vaginalis is s____ transmitted
sexually
Symptoms of trichomonas vaginalis
Dysuria, yellow frothy discharge, fertility issues
How is trichomonas vaginalis managed?
Metronidazole and contact tracing
How is Giardia spread?
Faeco-orally
Symptoms of Giardia
Diarrhoea, cramps, bloating, flatulence, trophozoites/cysts seen in stool
After having Giardia, can have intolerance to…
lactose
What antibiotic is used to treat giardia?
Metronidazole
Entamoeba histolytica is spread…
faeco-orally
Symptoms of amoebiasis
Dysentry, colitis, liver and lung abscesses
Cryptosporidiosis is w_____ and causes diarrhoea, vomiting, fever and weight loss
waterborne
What is seen in stool with cryptosporidiosis?
Oocytes
Toxoplasmosis is spread by…
Ingestion of contaminated food and water, feline faeces
What can toxoplasmosis cause?
Disseminated disease, toxoplasma encephalitis, chorioretinitis
What is advised in pregnancy to prevent toxoplasmosis?
Avoiding raw or cured meats, avoid unpasteurised goats milk products, wear gloves and wash hands or avoid gardening or cleaning cat litter trays
What is the most common reason for fever on return from travel?
Malaria
How many species of malaria cause human disease?
5
(plasmodium…falciparum
ovale, vivax, malariae, knowlesi
How is malaria diagnosed?
Light microscopy on blood film to see trophozoite.
Thick screen is low resolution but determines presence of malaria.
Thin screen identifies which species.
Other symptoms of malaria (other than fever)
Chills, headache, myalgia, fatigue, diarrhoea, vomiting, abdo pain
Malaria signs
Anaemia, jaundice, hepatosplenomegaly, Black water fever (haemoglobin passes into urine so becomes very dark)
Brief outline of malaria cycle
Mosquito bites infected human and ingests plasmodium gametocytes.
Develops in midguts , sporozoites in salivary glands.
Injects in next bite
Sprozoites infects hepatocytes.
Develops into schizont, burst and infects RBCs.
Becomes trophozoite.
Develops into a schizont, ruptures and infects another RBC.
Some trophozoites develop into gaetocytes.
Malaria causes haemolysis causing…
Anaemia and jaundice from bilirubinaemia
Certain type of malaria, P.falciparum is more complicated due to infected RBCs increased ability to…
adhere to endothelial cells
Small vessels can become obstructed by clumps of RBCs causing
hypoxia, microinfacts in brain and lung
Vascular occlusion causes
drowsiness (systemic hypoglycaemia), raised intracranial pressure, seizures, coma and death.
Anaemia and lacticacidosis can cause t_____ through compensatory mechanisms
tachypnoea
Increased vascular permeability in lungs causes
pulmonary oedema
Renal failure can occur due to…
vascular occlusion, hypoperfusion secondary to dehydration or hypotension, haemolysis creating nephrotoxic products.
Reduced circulating platelets is due to…
thrombocytopenia and platelet aggregation
