Parasitic infections - Malaria

Question 1

What is the main characteristic of Amoeba?

Answer 1

Move by pseudopodia

Question 2

What is the main characteristic of Flagellates?

Answer 2

Have flagella

Question 3

What is the main characteristic of Ciliates?

Answer 3

Have cilia

- most not pathogenic

Question 4

What is the main characteristic of Apicomplexa (sporozoa)

Answer 4

Have apical complex

- all are parasitic

Question 5

The protozoa that cause Malaria are of the genus…

Answer 5

Plasmodium

Question 6

What are the 4 species of Plasmodium that cause Malaria in humans?

Answer 6

P.falciparum
- Tropics, main problem in africa & SE asia
P. Vivax
- Widely distributed, main cause of malaria outside of africa
P. Ovale
- Tropics, africa & SE asia
P. Malariae
- Widely distributed, but more rare

Question 7

How is Malaria transmitted?

Answer 7

1. Parasites injected with saliva of female mosquitoes
2. Multiply in liver, then infect RBCs
3. Mosquitoes ingest parasites with blood
4. Parasites go through reproductive phase inside the mosquito

Question 8

What are the main symptoms of Uncomplicated Malaria?

Answer 8

Cold stage - shivering
Hot stage - fever
Sweating stage

(Other: headache, body aches, nausea/vom, enlarged spleen etc)

Question 9

How long does a classical malaria attack last?

Answer 9

6-10 hours

Question 10

Describe the periodicity of P.falciparum

Answer 10

Irregular

Question 11

Describe the periodicity of P.vivax/ovale

Answer 11

Tertian

Question 12

Describe the periodicity of P.malariae

Answer 12

Quartan

Question 13

What are the main symptoms of Complicated Malaria?

Answer 13

Cerebral malaria (abnormal behaivour, seizures, coma etc)
Shock (sudden drop in blood flow)
Severe anaemia
Pulmonary oedema
Liver failure (jaundice)
Swelling, rupturing of spleen

Question 14

What are the main methods of diagnosis for Malaria?

Answer 14

Blood smears examined by microscopy
- can take time, requires technical expertise
Rapid diagnositc tests (RDTs)
- fast but limited sensitivity

Others: PCR, antibody detection, mass spec
- Expensive, require technical expertise

Question 15

On the BinaxNow Malaria test, T1 is specific to…

Answer 15

P.falciparum (HRPII)

Question 16

On the BinaxNow Malaria test, T2 is specific to…

Answer 16

All other causes apart from P.falciparum

- LDH

Question 17

Which is more sensitive, T1 or T2?

Answer 17

T1

Question 18

How is malaria caused by P.falciparum treated?

Answer 18

• Quinine followed by doxycycline or clindamycin
• Atovaquone-proguinil (Malarone)
• Arthemether-lumefantrine (Riament/Co-artem)

Question 19

How is malaria caused by Plasmodium infections other than P.falciparum treated?

Answer 19

Chloroquine

followed by primaquine (for P.vivax and P.ovale)

Question 20

What is the mode of action of Atovaquone?

Answer 20

Inhibits mitochondrial metabolism

Question 21

What is the mode of action of Chloroquine?

Answer 21

Inhibits haem detoxification

Question 22

What is the mode of action of Lumefantrine?

Answer 22

Inhibits haem detoxification

Question 23

What is the mode of action of Mefloquine?

Answer 23

Inhibits haem detoxification

Question 24

What is the mode of action of Proguanil?

Answer 24

Antifolate

Question 25

What is the mode of action of Pyrimethamine?

Answer 25

Antifolate

Question 26

What is the mode of action of Sulphadoxine?

Answer 26

Antifolate