Malaria Flashcards

1
Q

What are plasmodium?

1 - fungi
2 - bacteria
3 - virus
4 - protozoan

A

4 - protozoan
- single cell parasite
- plasmodium is a genus then within this there will be species

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2
Q

What % of deaths due to malaria occur in children <5 y/o?

1 - 20%
2 - 35%
4 - 44%
4 - 67%

A

4 - 67%
- 1 child dies every minute from malaria

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3
Q

If someone has had International travel, which of the following should we suspect the most for risk of malaria?

1 - Russia
2 - Australia
3 - Africa
4 - Japan

A

3 - Africa
- Nigeria accounts for the majority of malaria cases

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4
Q

What is the single most important infection that travellers returning to the UK are infected with?

1 - TB
2 - hepatitis B
3 - malaria
4 - impetigo

A

3 - malaria

  • 1300-1800/year
  • kills 6/year in the UK
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5
Q

There are 5 main species of Plasmodium that we need to be aware of. Which of the following is most common?

1 - P. falciparum
2 - P. vivax
3 - P. ovale
4 - P. malarie
5 - P. knowlesi

A

1 - P. falciparum

  • the incidence of each species is affected by geographical distribution, lifecycle, clinical features, demographics and reservoir
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6
Q

Patients infected with malaria can present with fever paroxysms, which is essentially where a patient experiences fevers and chills intermittently. P. falciparum is the most common cause of malaria and causes malignant tertian fever paroxysms. What time period does the malignant tertian fever paroxysm occur in a patient infected with P. falciparum?

1 - 12h
2 - 24h
3 - 48h
4 - 72h

A

3 - 48h

P. vivax = Benign tertian 48 hours
P. ovale =Benign tertian 48 hours
P. malarie = Quartan 72 hours

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7
Q

What are the 2 main tissues/organs infected initially by malaria?

1 - WBCs
2 - spleen
3 - liver
4 - RBCs

A

3 - liver
4 - RBCs

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8
Q

Once a human has been infected by plasmodium, the parasite makes its way to the liver. What is this stage of the parasites life cycle called?

1 - erythrocytic phase
2 - reproductive phase
3 - exoerythrocytic phase
4 - replicative phase

A

3 - exoerythrocytic phase
- because it occurs outside the RBCs
- replication here is aysexual and typically patients are asymptomatic

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9
Q

In the exoerythrocytic phase which occurs in the liver, the parasites take over hepatocytes and those infected hepatocytes become what?

1 - gametocytes
2 - merozoites
3 - sporozoites
4 - schiizont

A

4 - schiizont

the schiizont contains lots of merozoites and eventually ruptures releasing the merozoites into the blood

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10
Q

In the exoerythrocytic phase which occurs in the liver the parasites become schiizon. Do all species of the plasmodium become schiizont?

A
  • no
  • P. vivax and ovale do not divide and become hypnotise
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11
Q

What is the name of the life cycle phase called when the schiizonts enter the blood stream and infect the RBCs?

1 - erythrocytic phase
2 - reproductive phase
3 - exoerythrocytic phase
4 - replicative phase

A

1 - erythrocytic phase
- because it occurs in RBCs

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12
Q

During the erythrocytic phase of the life cycle of plasmodium, schiizonts are formed from mature liver hepatocytes that contain lots of merozoites. The schiizonts typically rupture releasing merozoites into the blood. The merozoites then bind and enter RBCs where they mature called the erythrocytic phase. They resemble a ring early on and is called what?

1 - early trophozoite
2 - merozoites
3 - sporozoites
4 - schiizont

A

1 - early trophozoite
- it can then develop into a late trophozoite

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13
Q

The late trophozoite are able to continue to grow in RBCs by digesting what within the cells?

1 - cholesterol
2 - haemoglobin
3 - phospholipids
4 - glucose

A

2 - haemoglobin
- this is why we can see anaemia in malaria patients

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14
Q

Which part of the erythrocytic phase is where merozoites actually replicate?

1 - early trophozoite
2 - late trophozoite
3 - schizont
4 - throughout erythrocytic phase

A

3 - schizont
- these can then differentiate into lots of merozoites and be released into the blood

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15
Q

Once schizont has developed, they can then differentiate into lots of merozoites and be released into the blood and repeat the erythrocytic phase. Does this happen to all merozoites?

A
  • no
  • some undergo gametogony
  • merozoites become gametocytes, which is where they can differentiate into male or female versions BUT remain in RBCs
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16
Q

Merozoites that undergo gametogony can become gametocytes, which is where they can differentiate into male or female versions and remain in RBCs. If a mosquito then samples that RBC what happens to these gametocytes?

1 - the mosquito becomes infected and dies
2 - the gametocytes differentiates back into a merozoites
3 - gametocytes enter GIT of mosquito and become a zygote
4 - all of the above

A

3 - gametocytes enter GIT of mosquito and become a zygote

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17
Q

Once inside the GIT of a mosquito, the gametocytes matures before becoming a zygote through sexual reproduction. Organise the subsequent steps of the plsamodium life cycle?

1 - sporozoites travel from the GIT to the salivary glands of mosquito
2 - oocyst develops
3 - zygote matures and becomes an ookineat
4 - oocyst ruptures inside mosquitos gut

A

3 - zygote matures and becomes an ookineat
2 - oocyst develops
4 - oocyst ruptures inside mosquitos gut
1 - sporozoites travel from the GIT to the salivary glands of mosquito

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18
Q

What stage of the plasmodiums life cycle do patient typically present with symptoms?

1 - during gametogony
2 - following the bite of the mosquito
3 - during ruptured schizont of hepatocytes
4 - during late trophozoite

A

3 - during ruptured schizont of hepatocytes

  • this occurs during the exoerythrocytiuc cycle
19
Q

Infected RBCs are able to be screened and destroyed if they are infected by the spleen. However, P. falciparum is able to do what to stop it from being destroyed in the spleen?

1 - induces necrosis of parenchyme of the spleen
2 - triggers autoimmune disease that targets the spleen
3 - increase secretion of plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) by RBCs
4 - able to go undetected by the spleen

A

3 - increase secretion of plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) by RBCs

  • PfEMP1 leads to RBCs clumping together and blockages arteries
  • so if the RBCs dont get to the spleen they cannot be destroyed
20
Q

RBCs infected with plasmodium falciparum are able to increase the secretion of plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) by RBCs, causing RBCs to clump together and block arteries. Does this have any affect on the brain?

A
  • yes
  • causes cerebral malaria due to severe hypoxia and hypoglycaemia
  • can also cause hyperpyrexia and metabolic acidosis
21
Q

Which of the following are causes of anaemia in malaria?

1 - late trophozoite digest haemoglobin for growth
2 - haemolysis of RBCs and release of trophozoites
3 - spleen destroys infected RBCs
4 - RBCs become sequestered due to increased levels of PfEMP1
5 - impaired erythropoiesis
6 - all of the above

A

4 - all of the above

22
Q

Malaria can cause a reduction in erythropoiesis. What is the most common cause that this occurs?

1 - cytokines are released in response to infection, which can suppress bone marrow
2 - inhibition of erythropoietin release by the kidney
3 - infection of bone marrow
4 - infection of lymphocytes

A

1 - cytokines are released in response to infection, which can suppress bone marrow

23
Q

How does malaria lead to metabolic acidosis?

1 - reduces perfusion in lungs
2 - increases HCO3- excretion in kidneys
3 - induces hypoxia, leading to an increase in lactic acid
4 - all of the above

A

3 - induces hypoxia, leading to an increase in lactic acid

24
Q

What is the typical incubation period for malaria?

1 - 1 day
2 - 6 days
3 - 14 days
4 - 21 days

A

2 - 6 days

  • difficult to present with malaria symptoms within 6 days of getting bitten by mosquito
25
Q

The typical incubation period for P. Falciparum malaria is 6 days. What time period do patients typically present with symptoms with this specific infection following returning to the UK after being in an infected area?

1 - <1 day
2 - <6 days
3 - <21 days
4 - <3 months

A

4 - <3 months

26
Q

Patients infected with malaria can be asymptomatic, uncomplicated or severe. Is severe malaria dangerous?

A
  • yes
  • medical emergency, similar to sepsis affecting multiple organs
27
Q

What is the mortality rate in the first 24h with severe malaria?

1 - 1-5%
2 - 10-20%
3 - 10-40%
4 - >50%

A

3 - 10-40%

28
Q

Which of the following patients are at risk of developing severe malaria?

1 - older patients
2 - children
3 - immune deficiency
4 - all of the above

A

4 - all of the above
- all are immunocompromised

29
Q

Which of the following patients is least likely to develop severe malaria?

1 - middle aged immunised male
2 - children
3 - young black adult
4 - native individual from infectious area

A

4 - native individual from infectious area
- developed some immunity following previous infections

30
Q

Which 2 of the following are tests used to diagnose malaria?

1 - thin blood film smear
2 - rapid diagnostic test
3 - thick blood film smear
4 - all of the above

A

4 - all of the above

31
Q

What stain is used in thick and thin blood smears when trying to diagnose malaria?

1 - giemsa stain
2 - acid fast stain
3 - gram stain
4 - ziehl–neelsen stain

A

1 - giemsa stain

32
Q

The thin and thick blood film tests and rapid diagnostic test (RDT)
can be used to diagnose malaria. Which are preferred?

A
  • thick and think blood smears
  • RDT done in addition
33
Q

If a thick of thin blood film smear is negative, does that automatically mean the patient doesn’t have malaria?

A
  • no
  • blood smear should be repeated between 12-24h and then again at 24h
  • if all are negative then patient is unlikely to have malaria
34
Q

Does the thick or thin blood smear able to identify the specific parasite better?

A
  • thin blood smear
35
Q

Does the thick or thin blood smear able to identify the the number of RBCs infected better?

A
  • thick blood smear
36
Q

When performing thick blood smear microscopy in an attempt to diagnose malaria, what cut off is used to confirm a patient has severe malaria?

1 - >2% RBCs infected
2 - >10% RBCs infected
3 - >20% RBCs infected
4 - >30% RBCs infected

A

2 - >10% RBCs infected
- >2% suggests severe malaria

37
Q

Which of the following is the 1st line treatment option for a patient with uncomplicated falciparum malaria?

1 - Atovaquone–proguanil
2 - IV ARTESUNATE
3 - Artemisinin combination therapy (ACT)
4 - Quinine plus doxycycline

A

3 - Artemisinin combination therapy (ACT)
- Artemisinin is combined with other drugs due to drug resistance

38
Q

Which of the following is the 1st line treatment option for a patient with severe falciparum malaria?

1 - Atovaquone–proguanil
2 - IV ARTESUNATE
3 - Artemisinin combination therapy (ACT)
4 - Quinine plus doxycycline

A

2 - IV ARTESUNATE
able to act at the ring stage called the tropnozite
- reduces infection and complications of infection

39
Q

Patients with sickle cell disease or sickle cell traits are typically protected from being infected by malaria, why is this?

1 - sickle cell RBCs more prone to hypoxia
2 - odd shape creates hostile environment in RBCs
3 - body is more effective at destroying odd shaped RBCs
4 - reduces adherence to and RBC sequestration
5 - all of the above

A

5 - all of the above
- all essentially limit the ability of malaria to grow and replicate

40
Q

Which species of plasmodium is unable to infect RBCs who are duffy receptor negative?

1 - P. falciparum
2 - P. vivax
3 - P. ovale
4 - P. malarie
5 - P. knowlesi

A

2 - P. vivax
- uses the duffy receptor to bind and infect RBCs

41
Q

When trying to prevent the risk of malaria, we can use the ABCD approach. What does A relate to?

1 - awareness of risk
2 - allergies
3 - autoimmunity

A

1 - awareness of risk
- therefore risks can be reduced

42
Q

When trying to prevent the risk of malaria, we can use the ABCD approach. What does B relate to?

1 - being careful
2 - bite prevention
3 - biodiversity approaches

A

2 - bite prevention
- clothing, repellant, insecticide treated net

43
Q

When trying to prevent the risk of malaria, we can use the ABCD approach. What does C relate to?

1 - counteracts
2 - consider alternatives
3 - chemoprophylaxis

A

3 - chemoprophylaxis
- taking medication prior to travelling to a malaria affected area

44
Q

When trying to prevent the risk of malaria, we can use the ABCD approach. What does D relate to?

1 - Diagnose promptly
2 - Decide on treatment
3 - Don’t travel unnecessarily

A

1 - Diagnose promptly