21. Fever in a Returning Traveler

Overview

Subjective illness is common after traveling and up to 10% of patients with recent international travel will seek healthcare. Remember, patients with recent travel are at risk for travel-related and non-travel related infections.

Risk Factors

  • Exposures: eating habits (see below), fresh water (schistosomiasis, leptospirosis), insect (mosquitos and ticks), sexual history, IDU, animal contact, sick contacts.
  • Eating habits and their associations: unpasteurized dairy (Brucella, Campylobacter, Salmonella, M. bovis), shellfish (Vibrio, enteric viruses), undercooked beef (Toxoplasma, Campylobacter, E. coli O157:H7).
  • If taking malaria prophylaxis, ask the patient which drug and to describe the dosing schedule as they are often not taken as directed.
  • In general, insect exposure cannot be ruled out with a negative history.
  • Most travel vaccines are highly efficacious (when given at the correct time) with the exception of typhoid (<70%, both oral and IM).
  • Consider non-travel related infections (e.g. CAP, UTI, etc.) or non-infectious causes (medications, VTE, malignancy, etc.).

Evaluation

  • Physical exam: evaluation for skin lesions, lymphadenopathy, retinal/conjunctival changes, hepatosplenomegaly, neuro findings, or genital findings.
  • Blood tests: CMP, CBC with diff (look for eosinophils to suggest helminths), blood culture (typhoid), thick and thin malaria smears (repeat if initial smears are negative and there is no alternative diagnosis), CXR.
  • Most traveler’s diarrhea is self-limited within 48-72 hours and does not require routine stool cultures. If diarrhea > 10 days, send stool for Giardia, Cryptosporidium, and E. histolytica (depending on travel location). Consider stool cultures (or PCR panels), O+P, and fecal WBCs if patient with fever +/- bloody diarrhea. Evaluate severity of hypovolemia.
    • Note in some cases, infection may have resolved and the patient now has post-infectious IBS.
  • Consider the frequency of endemic disease in the region and incubation period of potential illness. Use the GeoSentinel database.
  • Most bacteria and viruses have short incubation periods (within 2 weeks)

Infections by Incubation Period

<14 DAYS

  • Bacterial: rickettsiae, leptospirosis, typhoid, meningococcus, Q fever.
  • Viral: dengue, acute HIV, hemorrhagic fever, arboviral encephalitis, influenza, chikingunya, Zika.
  • Parasitic: malaria, East African trypanosomiasis.

2 to 6 WEEKS

  • Bacterial: typhoid (but usually <18 days), leptospirosis (but usually <12 days), Q fever.
  • Viral: hepatitis A, E, acute HIV, East African trypanosomiasis, hemorrhagic fever (but usually <14 days).
  • Parasitic: malaria, acute schistosomiasis, amebic liver abscess.

>6 WEEKS

  • Bacterial: TB.
  • Viral: hepatitis B, E.
  • Parasitic: malaria, leishmaniasis, filariasis, schistosomiasis, amebic liver abscess, African trypanosomiasis.
  • Fungal: endemic mycoses.

Common Infections by Geography

  • Tropical travel: dengue (commonly in patients returning from SE Asia, Latin America and the Caribbean), malaria (most common cause overall and in particular in sub-Saharan Africa), typhoid (S. typhi and paratyphi), rickettsial disease, enteric infections, mononucleosis. Less commonly: leptospirosis, chikungunya, acute schistosomiasis, amebiasis (liver abscess), acute HIV, and viral hepatitis.
  • Sub-Saharan Africa: malaria (esp. P falciparum). There is also an increase in rickettsial illness (African tick-bite fever) in this region. 
  • Respiratory illnesses account for around 15% of all causes of fever in a returned traveler (25-40% in Northern Asia, Europe, Australia and New Zealand), and around 20% overall have an undiagnosed febrile illness.

Key Points

  • Remember to consider non-travel related illness (e.g., was the patient exposure pre- or post-travel). Infections can also be acquired en route or on brief layovers.
  • Don’t anchor on the travel, the illness could be completely unrelated.
  • Defining the possible incubation period may help limit the differential diagnosis.
  • Risks for infectious diseases vary between regions and depending on the time of year.
  • Non-infectious etiologies: consider drug fever related to travel meds, thromboembolic disease, malignancy.
  • Rashes: consider dengue, chikungunya, acute HIV, measles.
  • Eosinsophilia: acute schistosomiasis, strongyloidiasis, filariasis, ascaris, hookworms.

Please see the CDC travel information site for country-specific information: http://wwwnc.cdc.gov/travel/

https://www.cdc.gov/vhf/abroad/diagnosis-considered-returning-traveler.html

 

Thwaites GE, Day NP. Approach to Fever in the Returning Traveler. N Engl J Med. 2017;376(6):548‐560. doi:10.1056/NEJMra1508435

Lo Re V 3rd, Gluckman SJ. Fever in the returned traveler. Am Fam Physician. 2003;68(7):1343‐1350.

Freedman et al. Spectrum of disease and relation to place of exposure among ill returned travelers. N Engl J Med 2006; 354:119.

Wilson, Mary E., et al. "Fever in returned travelers: results from the GeoSentinel Surveillance Network." Clinical infectious diseases 44.12 (2007): 1560-1568.

Leder, Karin, et al. "GeoSentinel surveillance of illness in returned travelers, 2007–2011." Annals of internal medicine 158.6 (2013): 456-468.

Mandell GL, Bennett JE, Dolin R. Principles and Practice of Infectious Diseases, Sixth Edition. Churchill Livingstone;2005.

Key words: Fever, Travel, Malaria, Chikungunya, dengue, eosinophilia, rash, Salmonella, Typhoid, Japanese encephalitis