MALARIA

Question 1

What are the four species that cause malaria?

Answer 1

Plasmodium falciparum
Plasmodium ovale
Plasmodium vivax
Plasmodium malariae

Question 2

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

Answer 2

The female Anopheles mosquito

Question 3

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

Answer 3

Sporozoites

Question 4

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

Answer 4

The liver

Question 5

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

Answer 5

Asexual reproduction

Question 6

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

Answer 6

Merozoites

Question 7

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

Answer 7

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

Question 8

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

Answer 8

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.

Question 9

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

Answer 9

P. vivax

P. ovale

Question 10

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

Answer 10

P. malariae

Question 11

What is the incubation period for P. falciparum parasite?

Answer 11

7-14 days

Question 12

What is the incubation period for P. ovale parasite?

Answer 12

10-18 days

Question 13

What is the incubation period for P. vivax parasite?

Answer 13

10-17 days

Question 14

What is the incubation period for P. malariae parasite?

Answer 14

18-42 days

Question 15

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

Answer 15

36-48 hours

Question 16

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

Answer 16

36-48 hours

Question 17

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

Answer 17

36-48 hours

Question 18

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

Answer 18

72 hours

Question 19

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

Answer 19

All of them especially the younger ones

Question 20

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

Answer 20

Reticulocytes

Question 21

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

Answer 21

Reticulocytes

Question 22

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

Answer 22

Older cells

Question 23

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

Answer 23

20%

Question 24

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

Answer 24

Benign malarias

Question 25

How might someone with malaria present?

Answer 25

``` Travel history Periodic chills Rigors Periodic high fevers Drenching sweats Vomiting ``` ``` Prodrome: Headache Malaise Myalgia Anorexia ```

Question 26

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

Answer 26

P. falciparum

Question 27

Can people from endemic areas build immunity to malaria?

Answer 27

Yes

Question 28

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

Answer 28

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

Question 29

What might you notice on examination of someone with malaria?

Answer 29

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

Question 30

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

Answer 30

P. malariae - chronicity of disease

Question 31

Which species of plasmodium causes cerebral malaria?

Answer 31

P. falciparum

Question 32

What are the features of cerebral malaria?

Answer 32

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.

Question 33

What investigations should be ordered for someone with suspected malaria?

Answer 33

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

Question 34

What might the blood tests of someone with malaria show?

Answer 34

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

Question 35

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

Answer 35

Schizont - cell with replicating parasites | Parasites themselves

Question 36

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

Answer 36

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

Question 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?

Answer 37

Three films on consecutive days

Question 38

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

Answer 38

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

Question 39

What might the urine dipstick of someone with malaria reveal?

Answer 39

Haemoglobinuria

Question 40

Why is an ECG important in someone with malaria?

Answer 40

Quinine can induce arrythmias and conduction defects

Question 41

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

Answer 41

To rule out bacterial meningitis

Question 42

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

Answer 42

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

Question 43

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

Answer 43

Chloroquine + Primaquine Always use different drug to prophylaxis though

Question 44

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

Answer 44

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

Question 45

What are the side effects of mefloquine?

Answer 45

Neuropsychiatric side effects

Question 46

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

Answer 46

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

Question 47

What are the complications of falciparum malaria?

Answer 47

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

Question 48

What are the side effects of doxycycline?

Answer 48

Sun sensitivity

Question 49

What are the side effects of chloroquine?

Answer 49

Headache Psychosis Retinopathy

Question 50

What are the side effects of quinine?

Answer 50

``` Retinopathy Optic atrophy Lichnoid planus (skin reaction) Thrombocytopenia Tinnitus ```

Question 51

What are the side effects of primaquine?

Answer 51

Haemolysis in those with G6PD deficiency.

Question 52

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

Answer 52

Destroys the liver hypnozoites to prevent relapse