Parasites

Question 1

What are the most common causes of fever in a returning traveler?

Answer 1

1. Dengue
2. Malaria
3. Typhoid
4. Rickettsia
5. Mono
6. Influenzae

Question 2

List the 4 species responsible for human malaria.

Answer 2

• Plasmodium falciparum
• Plasmodium ovale
• Plasmodium vivax
• Plasmodium malariae

Question 3

Which species develop dormant hypnozoites in the liver?

Answer 3

• P. vivax and ovale: recurrence of infections months to years later

Question 4

List clinical features of malaria

Answer 4

1. cerebral edema
2. jaundice
3. hypoglycemia
4. acidosis
5. Pulmonary edema
6. renal failure
7. GI dysfunction
8. Coagulopathy/thrombocytopenia

Question 5

List complications of severe malaria (P falciparum)

Answer 5

• Cerebral malaria – cerebral edema and encephalopathy
• Metabolic acidosis
• Severe anemia
• Pulmonary edema
• DIC
• Death

Question 6

How is the diagnosis of malaria made?

Answer 6

• Thick and thin smears. Repeat every 8-12h for 1-2 days, until traveler clinic follow-up, or continue is there is a strong suspicion of malaria
  o Thick: More SN: larger amount of blood
  Thin: Less SN, used to speciate, able to calculate parasetemia level

Question 7

Outline your approach to the treatment of malaria:

Answer 7

1. ABC’s:
   a. More cautious with fluids, risk of pulmonary edema large in severe malaria
2. Source control: anti-malarials:
   a. Uncomplicated: PO
   b. Severe: IV
   c. Think about co-infections à bacterial sepsis
3. Exchange transfusion
   a. Consider in critically unwell patient not responding to treatment, and parasetemia load >10%
   b. Unclear evidence if actually works
4. Sz:
   a. Rule out and treat hypoglycemia
   b. IV BZD

Question 8

What treatment regimes are recommended for malaria treatment?

Answer 8

• Chloroquine sensitive: Adult & peds:
  o Chloroquine (Clinda if chloroquine resistant)
  o Hydroxychloroquine
  o Artesunate
• Chloroquine resistant + Severe malaria (Can give these PO or IV depending on severity):
  o Quinine
  o Artesunate

Question 9

List parasites that cause fever.

Answer 9

• Malaria sp
• Borellia sp
• Babesiosis
• Shistosomiasis
• Fasciioliasis (Liver fluke)
• African trypanosomiasis (sleeping sickness)
• American trypanosomiasis (Chaga’s disease)
• Leishmeniasis
• Toxoplasmopsis
• Amebic liver abscess

Question 10

What is the most common cause of myocarditis in the developing world?

Answer 10

• Chagas!!
• Kissing bug bites around eye: excretes T. cruzi into wound: forms a chagona à migrates to muscle (pref smooth muscle anywhere!)
• Cardiomyopathy not seen in acute illness, but in chronic chagas which complicates 25% of cases

Question 11

List 4 parasites that can cause neurological Sx:

Answer 11

• Cerebral malaria
• Cysticercosis
• Echinococcosis
• African Trypanasomiasis
• Trichinella spiralis
• E. histolytica
• Strongyloides sterocoralis
• Naegleria
• Schistosoma