What infections should be considered?
What questions should be asked in the travel history?
What diagnostic tests should be conducted?
Which patients should be hospitalized?
What clinical factors put patients at risk for serious complications?
When should an infectious disease physician be consulted?
THE GREAT PRETENDER
A middle-aged male was brought in by police to the emergency room of an inner-city hospital with confusion and fever to 104°F, after being found in an incoherent state without identification. Shortly after arrival, his condition deteriorated. He became agitated, hypoxic, and hypotensive and was intubated and transferred to the intensive care unit. A chest radiograph showed diffuse infiltrates. Blood tests were most notable for a hematocrit of 18%, creatinine 2.8 mg/dL, and moderate elevations of liver enzymes. A lumbar puncture was normal. The hematology laboratory technician happened to review the patient's blood smear before going home that evening and made a diagnosis of falciparum malaria with 30% parasitemia. The patient was started urgently on intravenous quinidine and exchange transfusions. He was eventually found to be a Nigerian immigrant who had recently traveled to his native country without taking malaria prophylaxis. After a stormy hospital course complicated by acute respiratory distress syndrome and acute renal failure, he made a full recovery.
Fever in travelers is malaria until proven otherwise. Malaria has been called “the mime” for its ability to simulate a wide variety of other infectious syndromes. Hence, the diagnosis of malaria is often missed or delayed, sometimes with fatal consequences, especially when patients present for care outside of endemic areas. For example, during the Vietnam War, returning soldiers who presented with malaria to civilian hospitals had a 10-fold higher mortality than those who presented to hospitals in the Veterans Administration system, which had much greater familiarity with diagnosing and treating malaria.
International travelers are commonly plagued by medical problems, particularly after travel to a resource-poor setting. About 8% of travelers to developing countries seek medical care while they are away or after they return. Although fever in the traveler may be caused by mild illnesses, it may also be a harbinger of potentially lethal infection. The evaluation of the febrile traveler is complicated by the wide array of possible etiologies. It is critical to consider which infections are endemic to the area visited, potential exposures, the time between exposure and the onset of symptoms, and associated clinical findings. This chapter reviews the common causes of fever in returning travelers and the appropriate initial diagnostic evaluation.
GeoSentinel, a worldwide network of travel and tropical medicine clinics, provides the largest database for travel-related infections. From 1996 to 2004, the five most common diagnoses for patients with systemic febrile illnesses presenting to GeoSentinel clinics from the developing world were malaria, dengue, mononucleosis due to Epstein-Barr virus or cytomegalovirus, rickettsial infection, and typhoid fever.
In the GeoSentinel database, malaria was the predominant ...