Infectious Diseases in Critical Care Medicine

more indolent processes or infections of longer incubation, and do not present until six months

or later. Time to presentation can be helpful to the clinician when generating a differential

diagnosis (see Table 1).

It is helpful to realize that the familiar adage “common things are common” applies also

to travel medicine. In a review of 25,023 patients within the GeoSentris database, there were no

reported cases of travel-related anthrax, yellow fever, primary amebic meningoencephalitis,

poliomyelitis, Rift Valley fever, tularemia, murine typhus, tetanus, diphtheria, rabies, Japanese

encephalitis, or Ebola (4). In the same report, of 17,353 patients, only one case each of the

following infections was identified:Angiostrongylus cantonensis, hantavirus, cholera, melioi-

dosis, Ross River virus, legionellosis, meningococcal meningitis, and African trypanosomiasis.

If any of these diagnoses is suspected, an infectious diseases consultation is recommended. As

malaria is the single most common life-threatening infection in returning travelers (Table 2), it

will be emphasized in this chapter. Other critical care infectious disease syndromes to be

Table 1 Fever in a Returned Traveler, Time to Presentation

<2wk 2–6wk >6wk

Malaria Malaria Malaria

Dengue Typhoid fever Tuberculosis

Rickettsial illness Hepatitis A, E Hepatitis B, E

Leptospirosis Katayama fever Visceral leishmaniasis

Typhoid fever Amebic liver abscess Lymphatic filariasis

East African trypanosomiasis Leptospirosis Schistosomiasis

Acute HIV Acute HIV Amebic liver abscess

VHF East/West African trypanosomiasis Chronic mycoses

Acute bacteremia Rabies

Acute diarrheal illness Viral hemorrhagic fever West African trypanosomiasis

Rabies Q fever

Arboviral encephalitis

Polio

Angiostrongyliasis

Influenza

Legionellosis

Histoplasmosis

Coccidioidomycosis

Q fever

Abbreviations: HIV, human immunodeficiency virus; VHF, viral hemorrhagic fever.

Source: Adapted from Ref. 7.

Table 2 General Considerations in Potentially Infected Critically Ill Returning Travelers

Diagnostic consideration Comments

Make accurate traveler- and itinerary-specific
risk assessment.

Obtain detailed history of sites visited, activities, and potential
infectious exposures.
Calculate approximate incubation period. Incubation periods: short (<10 days); intermediate (10–14 days);
prolonged (>21 days) A minimum period of 5–7 days before
considering malaria. Incubation period exceeding 3 wk rules out
arboviral etiologies.
Avoid narrow focus on “tropical infections.” Avoid becoming so focused on the international travel history that
common community-acquired infections such as pneumococcal
pneumonia, staphylococcal infections, etc. are not considered.
Use concomitant signs and/or symptoms. Narrow the differential diagnosis using clinical progression and
specific findings (i.e., diarrhea, rash, or respiratory complaints).
Rule out malaria. Always consider and perform diagnostic testing to evaluate for
malaria if a traveler has been in a malarious region with an
appropriate incubation period.

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