Malaria

Question 1

What is the difference between a prokaryotic vs eukaryotic cell

Answer 1

Prokaryotic cell organelles are not mebrane bound, but eukaryotic cell organelles are

Prokaryotes are unicellular, eukaryotes can be both

Prokaryotic cells are at least 100 times smaller than eukaryotic cells

Prokaryotic cells have circular DNA, eukaryotic cells have linear DNA

Prokaryotic cells reproduce by binary fission (asexually) eukaryotic cells can reproduce by mitosis/ meiosis (asexually) or sexually

Question 2

What is a protozoa?
Give an example

Answer 2

Single celled eukaryotic cell
Plasmodium (protozoa that causes malaria)

Question 3

What is an obligate parasite?

Answer 3

A parasite that can not survive independently as they require a host to complete their life cycle

Question 5

SS malaria

Answer 5

Fever - can be periodic, up to 41, anyone with unexplained fever ask about travel even several years ago to malaria endemic country

Chills
Rigors
Sweating
Diarrhoea
Abdominal pain
Respiratory distress
Seizures
Myalgia
Headache
N&V

Haemolytic anaemia - pallor and jaundice
Splenomegaly - infected RBC get phagocytosed
Hepatomegaly
Renal abnormalities
Confusion

Question 6

How do we diagnose malaria

Answer 6

Peripheral blood smear shows plasmodium

Rapid diagnostic tests

Question 7

Which factors guide antibiotic choice in malaria?

Answer 7

Plasmodium species

Clinical status

Drug sensitivity

Question 8

What is the most severe type of malaria caused by?

Answer 8

Plasmodium falciparum

Question 9

Which mosquito spreads plasmodium to humans?

Answer 9

The female anopheles mosquito

Question 10

What is the most common type of plasmodium ?

Answer 10

Plasmodium falciparum

Question 11

Which 5 species of plasmodium infect humans?

Answer 11

‘Know false, oval vixen malaria’

P. knowlesi
P. falciparum
P. ovale
P. vivax
P. malariae

Question 12

Describe the life-cycle of malaria

Answer 12

1. Anopheles mosquito feeds on infected blood
2. Plasmodium reproduces in mosquito’s gut to produce malaria spores aka sporozoites
3. Anopheles mosquito bites someone else so sporozoites enter their blood
4. Sporozoites travel to liver where they can lie dormant for years as hypnozoites if p.vivax or p.ovale are the cause.
5. Sporozoites mature into merozoites
6. Merozoites infect RBCs
7. Merozoites reproduce in RBCs causing them to rupture and get released

Question 13

Incubation period malaria

Answer 13

1-4 weeks after exposure, although can lie dormant for years

Question 14

How often does the rupture and release of different types of merozoites occur in the species of plasmodium?

Answer 14

Fever every other day/ 48h/ tertian malaria = p.vivax + p. ovale

More frequent/ irregular fever spikes = P. falciparum

Every 72h/ Quartan malaria = p. malariae

Question 15

How to exclude malaria as a diagnosis?

Answer 15

3 negative blood films over 3 consecutive days sent in EDTA (purple bottle)

Question 16

Malaria management

Answer 16

Admit everyone with p. falciparum

1st line uncomplicated malaria: Artemether with lumefantrine

1st line for complicated malaria (requiring HDU/ ITU admission): Artesunate or Quinine dihydrochloride (p.falciparum is treated with this)

Question 17

Complications p.falciparum malaria

Answer 17

Cerebral malaria
Seizures
Reduced consciousness
Acute kidney injury
Pulmonary oedema
Disseminated intravascular coagulopathy (DIC)
Severe haemolytic anaemia
Multi-organ failure and death

Question 18

What advice should give to patients travelling to malaria endemic areas

Answer 18

No method is 100% effective alone

Use mosquito spray (e.g., 50% DEET spray)

Use mosquito nets and barriers in sleeping areas

Seek medical advice if symptoms develop

Take antimalarial medication as recommended

Question 19

Which anti-malarial medication option for prophylaxis has the least side effects? How long is it taken for?

Answer 19

Proguanil with atovaquone (Malarone). It is taken from two days before until seven days after travel to an endemic area.