Fever in a returned traveller

History

• Pretravel
  • Vaccinations
  • Prophylaxis, e.g. malaria
  • Vector protection, including bed nets and mosquito spray
• Travel
  • Make explicit timeline of locations visited, for how long
  • Assess activities and exposures in each location
  • Food and water
  • Recreational water
  • Animals
  • Vectors
  • Sex
• Combine timeline of exposures with incubation periods to rule out diseases
  • Dengue: 3-5 days
  • Malaria: 7-21 days
  • Hepatitis A: 6 days to 6 weeks
  • Hepatitis B: 1-6 months
  • Typhoid: 7-21 days
  • Non-typhoidal Salmonella: 3-7 days

Differential Diagnosis

Disease	Incubation	Distribution	Exposures	Diagnosis
Viruses
Avian influenza	2-8 days	East and Southeast Asia	Poultry	PCR
MERS-CoV	2-14 days	Arabian peninsula	Infected humans or camels	PCR
Ebola, Lassa fever, or Marburg hemorrhagic fever	up to 22 days	Africa	Infected humans and animals	PCR
Crimean-Congo hemorrhagic fever	1-9 days (tick) or 3-13 days (contact)	Southern Europe, Middle East, Africa, northwestern China	Ixodes ticks or infected humans or animals	PCR

Investigations

• First-line
  • CBC
  • Liver enzymes and function, for viral hepatitides
  • Electrolytes, urea, and creatinine
  • Urinalysis, for proteinuria that would suggest Leptospirosis
  • Blood cultures x2, for enteric/typhoid fever
  • Thick and thin smears x3 over 3 days, for malaria
• Based on history and lab results
  • Urine culture
  • Stool culture and O&P
  • Hepatitis serologies
  • Serology for zika, chikungunya, and dengue viruses, with repeat in 14 days if negative
  • C. difficile toxin
  • NP swab

Further Reading

• Freedman DO, et al. Spectrum of Disease and Relation to Place of Exposure among Ill Returned Travelers. N Engl J Med 2006; 354:119-130.