Assessing Fever in a Returning Traveler with No Risk of Viral Hemorrhagic Fever

TOUR: Treat patient, Obtain history, Urine/blood work, Rule out malaria

This TOUR algorithm is for use by Emergency Room clinicians in assessing a patient with signs, symptoms, and/or diagnostic findings concerning for a possible infectious disease acquired during travel outside of the United States of America.

This algorithm is not intended to be a comprehensive guideline, and should be used in conjunction with your hospital’s established policies for managing fever in a returning traveler.

Initial management

  • Initial assessment of the patient should be the same as that for any ill patient suspected of having an infection to include the following as needed
    • Vital sign monitoring
    • Intravenous access
    • Ventilatory and hemodynamic support

Obtain a pertinent medical and travel history (in addition to standard history items)

  • Travel itinerary (countries and location in the country)
  • Duration of travel
  • Date of return from travel
  • Date of illness onset
  • Immunizations received pre-travel
  • Adherence to malaria prophylaxis
  • Accommodation (camping, etc.)
  • Activities abroad (safari, etc.)
  • Potential exposures:
    • Insect and/or animal bites/scratches
    • Foods (seafood, raw meat, etc.)
    • Medical care overseas or procedures such as piercing/acupuncture
    • Sexual activity

Conduct physical examination

  • Physical examinations of the patient should be the same as that for any patient suspected of having an infectious illness to include the following
  • Rashes, eschars, jaundice
  • Lymphadenopathy, hepatosplenomegaly
  • Neurological deficits, altered mental status, meningismus

Laboratory testing and radiologic studies

  • Fever in returned travelers is often caused by common, cosmopolitan infections such as pneumonia, and pyelonephritis, which should not be overlooked in search for exotic diagnosis.
  • Laboratory and radiographic studies should be the same as that for any patient suspected of an infectious illness to include the following as appropriate.
    • Complete blood count with differential and smear
    • Comprehensive metabolic panel
    • Coagulation profile
    • Urinalysis
    • Blood and urine cultures
    • Thick and thin blood smears and/or rapid malaria test
    • Cerebral spinal fluid analysis (preceded by computerized tomography (CT) of the head if indicated)
    • Chest x-ray


  • Early consultation with an infectious disease subspecialist may be helpful in arriving at a diagnosis.
  • Additional information on evaluating fever in a returning traveler can be found at CDC Yellow Book.

Malaria 101

  • Leading cause of travel-related hospitalization and death.
  • Consider malaria in any patient with a febrile illness who has recently returned from a malaria-endemic country.
  • Early diagnosis and treatment is critical to improve outcomes.
  • Initial symptoms include:
    • Fever (may be absent on presentation)
    • Nausea/vomiting,
    • Chills
    • Headache
    • Myalgias
    • Abdominal pain
    • Anemia
  • Patients who have one or more of the following clinical criteria are considered to have severe malaria:
    • Impaired consciousness (Glasgow coma score <11 in adults or Blantyre coma score <3 in children)
    • Prostration
    • Convulsions (greater than 2 in 24 hours)
    • Acidosis
    • Hypoglycemia
    • Severe anemia (Hgb <7 g/dL in adults or <5 g/dL in children)
    • High parasitemia (>10%)
    • Renal impairment (Cr >3 mg/dL)
    • Jaundice
    • Pulmonary edema
    • Significant bleeding (including recurrent or prolonged bleeding)

Diagnostic testing

  • Thick and thin smear microscopy remains the gold standard for malaria because it can be used to do the following
    • Determine the species of malaria parasite
    • Identify parasite life-cycle stages to present
    • Quantify parasitemia
  • Thick and thin smear microscopy should be done in all suspect malaria cases and repeated if initially
  • Rapid Diagnostic Tests (RDT) are a useful alternative to microscopy in situations where reliable microscopic diagnosis in not immediately available. CDC recommends positive and negative RDT results always be confirmed by microscopy in US healthcare settings.
    • Challenges with RDTs include the following:
      • Cannot distinguish between all five species of malaria that affect humans.
      • Less sensitive than expert microscopy or PCR.
      • Cannot quantify parasitemia.
      • Many will persist with a positive result for days or weeks after an infection has been treated and cleared.
  • PCR tests are available for detecting malaria parasites
    • More sensitive than microscopy
    • Results are usually not available as quickly as microscopy results, thus limiting the utility of this test for acute diagnosis.


  • Malaria can be treated effectively early in the course of the disease. Delay of therapy can have serious or even fatal consequences.
  • Detailed CDC recommendations for malaria treatment
  • Clinicians who require assistance with the diagnosis and treatment of malaria should call the CDC Malaria Hotline (770-488-7788) or toll free at 855-856-4713 from 9am to 5pm Eastern time
  • After hours or on weekends and holidays, clinicians requiring assistance should call the CDC Emergency Operations Center at 770-488-7100 and ask the operator to page the person on call for the Malaria branch
  • Consult with a clinician who specializes in travel or tropical medicine or with an infectious disease physician

Other diagnoses for consideration

If illness presentation is not consistent with malaria or malaria has been ruled out, consider other diagnoses based on specific clinical presentation and travel itinerary/place of possible exposure. Remember, travelers can have non-travel related reasons for fever, too!

  • Wilson, Mary Elizabeth. Chapter 5: Fever in Returned Travelers. CDC Yellow Book Travelers’ Health, Centers for Disease Control and Prevention. Accessed 27 September 2017.
  • Taylor, Terrie E. Treatment of severe malaria. In: UpToDate, Daily, Johanna (Ed), UpToDate, Waltham, MA, 2017.
  • Hopkins, Heidi. Diagnosis of malaria. In: UpToDate, Daily, Johanna (Ed), UpToDate, Waltham, MA, 2017.