MALARIA Flashcards Preview

HAEMATOLOGY > MALARIA > Flashcards

Flashcards in MALARIA Deck (52):
1

What are the four species that cause malaria?

Plasmodium falciparum
Plasmodium ovale
Plasmodium vivax
Plasmodium malariae

2

What is the name of the vector that is responsible for transmitting malaria?

The female Anopheles mosquito

3

What do we call the stage of the plasmodium life cycle where human are infected via the bite of the mosquito?

Sporozoites

4

Where do the sporozoites of plasmodium travel to when a human is bitten by the mosquito?

The liver

5

What stage of the plasmodium life cycle occurs in the human liver?

Asexual reproduction

6

What do we call the stage of the plasmodium life cycle which gets released into the blood from the liver in malaria?

Merozoites

7

At what stage of the life cycle of plasmodium does the patient start feeling fever?

When the merozoites are released into the blood stream from the hepatocytes

8

What happens to the merozoites of plasmodium in the blood stream during a malaria infection?

They infect red blood cells to further reproduce asexually. Each release of new merozoites causes a spike in fever, which gives malaria the characteristic cyclical spikes in fever.

9

Which species of plasmodium parasite can lay dormant in the liver leading to relapse of malaria?

P. vivax
P. ovale

10

Which species of plasmodium parasite can lay dormant in the blood stream leading to relapse of malaria?

P. malariae

11

What is the incubation period for P. falciparum parasite?

7-14 days

12

What is the incubation period for P. ovale parasite?

10-18 days

13

What is the incubation period for P. vivax parasite?

10-17 days

14

What is the incubation period for P. malariae parasite?

18-42 days

15

What is the time between each fever cycle (typical of malaria) of P. falciparum?

36-48 hours

16

What is the time between each fever cycle (typical of malaria) of P. ovale?

36-48 hours

17

What is the time between each fever cycle (typical of malaria) of P. vivax?

36-48 hours

18

What is the time between each fever cycle (typical of malaria) of P. malariae?

72 hours

19

Which red blood cells does P. falciparum tend to infect?

All of them especially the younger ones

20

Which red blood cells does P. ovale tend to infect?

Reticulocytes

21

Which red blood cells does P. vivax tend to infect?

Reticulocytes

22

Which red blood cells does P. malariae tend to infect?

Older cells

23

What is the mortality rate for someone infected with P. falciparum?

20%

24

What are P. ovale, P. vivax and P. malariae collectively called?

Benign malarias

25

How might someone with malaria present?

Travel history
Periodic chills
Rigors
Periodic high fevers
Drenching sweats
Vomiting

Prodrome:
Headache
Malaise
Myalgia
Anorexia

26

What species of malaria is now considered resistant to chloroquine in many parts of the world?

P. falciparum

27

Can people from endemic areas build immunity to malaria?

Yes

28

Does the immunity to malaria built up in those from endemic areas last forever?

No, if they live somewhere else for a few years they will lose their immunity, but may travel without knowing this.

29

What might you notice on examination of someone with malaria?

Fevers up to 41 degrees
Conjunctival pallor - anaemia
Jaundice - haemolysis
Hepatomegaly
Splenomegaly

30

Which species of plasmodium is most likely to cause splenomegaly? Why?

P. malariae - chronicity of disease

31

Which species of plasmodium causes cerebral malaria?

P. falciparum

32

What are the features of cerebral malaria?

Unrousable coma
Rapid decline from reduced consciousness to coma and then death
Many suffer fits
On examination may elicit upper motor neuron pattern and nystagmus.

33

What investigations should be ordered for someone with suspected malaria?

Blood film
FBC
U&E's
Lactate dehydrogenase
Bilirubin
Glucose levels
Urine dipstick
ECG
LP

34

What might the blood tests of someone with malaria show?

Anaemia
Thrombocytopenia
Renal impairment
Raised bilirubin - haemolysis
Raised lactate dehydrogenase - haemolysis

35

What might be seen on a blood film of someone with malaria?

Schizont - cell with replicating parasites
Parasites themselves

36

From a blood film, how might you determine the severity of malaria?

Presence of a schizont indicates severe malaria
Parasitaemia of more than 2% indicates severe malaria

37

How many blood films would you need to take from a patient to confirm that a patient does not have or no longer has malaria?

Three films on consecutive days

38

Why is it important to check glucose level in a malaria patient?

Hypoglycaemia will complicate P. falciparum
Hypoglycaemia is a possible side effect of quinine

39

What might the urine dipstick of someone with malaria reveal?

Haemoglobinuria

40

Why is an ECG important in someone with malaria?

Quinine can induce arrythmias and conduction defects

41

Why would you perform an LP in someone with suspected cerebral malaria?

To rule out bacterial meningitis

42

What is the gold standard treatment for malaria caused by P. falciparum or by unknown cause?

Artemisinin combination therapy (ACT):

Artemether-lumefantrine
Artesunate-amodiaquine
Dihydroartemisinin-napthoquine
Atovaquone-proguanil (Malarone)

These are now accepted to be better than quinine, doxycycline or clindamycin

43

What drug can be used to treat malaria known to be caused by non-falciparum malaria?

Chloroquine + Primaquine

Always use different drug to prophylaxis though

44

What prophylactic drugs can be given to travellers to protect them against malaria?

Chloroquine - not useful in a lot of areas of resistance
Quinine
Doxycycline
Mefloquine
Malarone

45

What are the side effects of mefloquine?

Neuropsychiatric side effects

46

Other than anti-malarial agents, what other treatment do malaria patients need?

Supportive care - fluids
Paracetamol for fever
Blood transfusions - platelets and red cell
ITU - especially if cerebral malaria

47

What are the complications of falciparum malaria?

Cerebral malaria
Septic shock
ARDS (adult respiratory distress syndrome)
AKI
DIC
Severe anaemia and thrombocytopenia
Hypoglycaemic
Hyperpyrexia

48

What are the side effects of doxycycline?

Sun sensitivity

49

What are the side effects of chloroquine?

Headache
Psychosis
Retinopathy

50

What are the side effects of quinine?

Retinopathy
Optic atrophy
Lichnoid planus (skin reaction)
Thrombocytopenia
Tinnitus

51

What are the side effects of primaquine?

Haemolysis in those with G6PD deficiency.

52

Why do we give primaquine to patients with non-falciparum malaria (ovale and vivax, not malariae)?

Destroys the liver hypnozoites to prevent relapse