Malaria Flashcards
What are the four main species of plasmodium?
Falciparum, vivax, ovale, malariae
What is the minimum incubation period for malaria?
6 days
What could the incubation period be up to for P. falciparum?
Up to 6 months
Why could the incubation period P vivax/ovale be up to 1 year+?
There is a dormant phase in the liver
What are the symptoms of malaria?
Fever, tiredness, vomiting, headaches
What signs/symptoms could be observed in severe faciparum malaria (parasites >2%)?
Tachycardia, hypotension, arrhythmias, ARDS, diarrhoea, cerebral malaria, low WCC, thrombocytopenia, metabolic acidosis, hypoglycaemia
How many blood smears must you get to diagnose malaria?
3
What investigations are required if malaria is suspected?
3 blood smears, FBC, U&Es, LFT, glucose, coagulation, head CT if CNS symptoms, CXR
What treatment is given if malaria is caused by P. faciparum?
Artesunate
What treatment is given if malaria is caused by P. vivax, ovale or malariae?
Chloroquine and primaquine
primaquine given to treat hypnozoites - liver
How can malaria be prevented?
Assess risk, know risk areas
Bite prevention - sprays, nets etc
Chemoprophylaxis
What are 3 examples of anti-malarials?
Atovaquone, proguanil, chloroqine
Which blood test needs to be done before commencing treatment with primaquine?
G6PD test (G6PD deficiency predisposes to haemolysis)
What is the name of the genus of the mosquito that carries malaria?
Anopheles mosquito
When the parasites (sporozoites) reach the liver, which receptors do they bind in order to get into hepatocytes?
Receptors for the serum proteins thrombospondin and properdin.
Two of the species of parasite, Plasmodium vivax and Plasmodium ovale , are able to form latent types that just hang around inside the hepatocytes for long periods. What are these called?
Hypnozoites
What do the parasites to when in the blood?
Bind to surface of RBCs
How do the parasites get into RBCs?
RBCs rich in glycophorin - contains sialic acid residues
Parastes bear molecule called lectin which binds to sialic acid
Which type of RBC do P. vivax and ovale affect?
Reticulocytes
Which type of RBC does P malariae affect?
Normoblasts
Why is P falciparum most severe?
Affects all ages of RBCs
How often does fever occur in malaria caused by P falciparum?
Every 3rd day
