Hot Topics from the Tropics

Question 1

• What types of parasites are there?

Protozoa
Metazoa
Ectoparasites

Answer 1

o Protozoa = single celled parasites (e.g. malaria, giardia)
o Metazoa = multicellular parasites (e.g. helminths)
o Ectoparasites = insects that don’t get inside you (e.g. fleas, mosquitoes)

Question 2

• What are the 4 types of malaria:

1. Plasmodium vivax
2. Plasmodium falciparum
3. Plasmodium ovale
4. Plasmodium malariae

• Which do we worry about the most + why?

Answer 2

Plasmodium falciparum, which can cause cerebral malaria

Question 3

• How long is the incubation period with malaria?

Answer 3

7-30 days (but in rare cases up to a year! So don’t exclude it in someone who has recently been to the tropics)

Question 4

• What is a hypnozoite?

in which types of malaria:

1. Plasmodium vivax
2. Plasmodium falciparum
3. Plasmodium ovale
4. Plasmodium malariae

Answer 4

A dormant form of a parasite. P. vivas and P. ovale can exists as hypozoites that produce relapses months or years later. Hence when you give treatment you need to ensure you kill these hypnozoite too.

Question 5

• What is viral haemorrhagic fever?

The main 4 viral infections that tend to cause haemorrhagic fever are:

L
M
E
C

Answer 5

A diverse group illnesses where you get fever and haemorrhages caused by a viral infection.

o Lassa
o Marburg
o Ebola
o Crimean-Congo haemorrhagic fever (CCHF)

Question 6

• What is the management of malaria?

what antimalarials?

Answer 6

o Antimalarials (quinine, doxycycline)

Question 7

• How is leishmaniasis transmitted?
• Why is the dog population important when thinking about leishmaniasis control?
• What are the two types of leishmaniasis?

How do you diagnose leishmaniasis?

Answer 7

Sand-flies

Because sandflies thrive off dogs

Visceral (where you get hepatosplenomegaly) and cutaneous (where you get a skin lesion)

Biopsy

Question 8

• How is trypanosomiasis transmitted in Africa and South America

and what does it cause:

• africa
• south america

Answer 8

o In Africa = testse fly (causes sleeping sickness which can wipe out villages because everyone is incapacitated and asleep)
o In South America = Rejuvid bug (causes Chagas disease where you get megaoesophagus, megacolon and cardiomyopathy)

Question 9

How do you treat trypanosomiasis?

Answer 9

Arsenic drug derivatives

Question 10

• What’s a classic history for someone who has just got schistosomiasis? “

Answer 10

“I swam in make Malawi 6 weeks ago and developed a swimmer’s itch. I now have a fever and blood in my urine”.

Question 11

schistosomiasis

How do you diagnose it?

What sort of urine sample do you want?

Answer 11

By looking for eggs in the urine (S. haematobium) or stool (S. japonicum/S. mansoni).

A terminal urine at midday (not mid-stream like for bacterial infections)

Question 12

• What is filariasis?

• caused by?
• leads to?

Answer 12

A parasitic disease caused by a roundworm infection that can clog up the lymphatic drainage of the limbs and cause elephantiasis

Question 13

cutaneous larva migrans:

• get into ?
• Tx?

Answer 13

Parasites that get into the foot, wiggle around for a few months and then die, but cause distress in the patient