A young woman returns from a 4 week trip with a febrile illness.  Her family doctor orders a blood film as part of the initial workup, and the following was seen.

What disease does she have and what treatment does she require?

This blood film shows a ring form trophozoite of the unicellular protozoan infection – from a plasmodium species. In other words, this patient has malaria!

A wise infectious disease physician once told me “Fever in a returned traveller is malaria until proven otherwise”.

Differential Diagnosis for Fever in a Returned Traveller:
Infections related to travel (i.e. Tropical Diseases)

• Malaria
• Dengue (South america and caribbean)
• Typhoid (South Asia)
• Influenza
• Hepatitis A
• Zika
• Chikungunya

Infections unrelated to Travel Location:

(whatever is in your differential diagnosis for local infectious processes e.g. pneumonia, UTI, cellulitis, viral infections)

Non-infectious Etiologies:

Malignancy and DVT always have to be considered in your differential.

Remember to ask returning travellers the following

1. Pre-Travel History:
   1. Did they seek pre-travel advice
   2. Immunizations received
      • Routine
      • Recommended
      • Required – Yellow fever, meningococcus
   3. Malaria prophylaxis
2. Travel itinerary
   • Exact dates
   • transfer points
   • long plane rides – DVT
   • Crowded busses
   • accommodations
   • Time of year
3. Exposure History:
   • What did you do while travelling?
   • Animal contact (humans, non-human mammals (brucella, Q fever, Rabies), arthropods, birds, reptiles)
   • Food and water (schistosomiasis, leptospirosis)
   • Specific Activities (especially sexual)
     • Caves – histoplasmosis, ebola
     • Safari – Malaria, rikettsiosis