Infectious Diseases: Malaria

Question 1

What causes malaria?

Answer 1

Vector = mosquito

Plasmodium: falciparum (most common), vivax, ovale

Question 2

What is the minimum incubation period of falciparum vs vivax/ovale?

Answer 2

F = min 6 day – 4 weeks

V/O = 6 days – 1 year

Question 3

What is the history/examination of malaria?

Answer 3

Fever

Chills

Sweats

Cycle every 3rd to 4th day

+/- splenomegaly

Severe headaches

Abdo pain

N+V

Question 4

Outline the possible side effects of malaria

Answer 4

CVS: tachycardia, hypotension, arrhythmias

Res: ARDS

GIT: diarrhoea, deranged LFTs,

CNS: confusion

Blood: low/norm WCC, DIC, thrombocytopenia

Renal: AKI

MET: acidosis, hypoglycaemia

Question 5

How should malaria be investigated?

Answer 5

Blood film x3 (parasites)

Rapid Dx test (Ag testing)

Bloods: FBC, LFTs, U+Es, Glu, coag, G+S

CT if neuro symptoms

CXR

Question 6

How should malaria be treated?

Answer 6

Falciparum = artesunate

Vivax/ovale = chloroquine

Question 7

Briefly outline the life cycle of malaria

Answer 7

1) mosquito feeds - sporozoite enters blood stream
2) make way to liver, infect hepatocytes
3) in hepatocytes: sporozoite devel to schizont = creating thousands of merozoites
4) merozoites burst out of cell, travel in blood steam
5) infect RBCs: reproducing, rupturing cell (massive destruction)
6) few cells devel to gametocytes = remain in blood several days
7) ingested by another mosquito - devel back to sporozoite