Of returning travelers who become ill, many have neither serious nor exotic illnesses.1 The most likely causes of acute symptoms are common problems such as upper respiratory infections, diarrheal illnesses, or reactions to stress, fatigue, or new medications. The ED physician often does not confirm the final diagnosis, but rather protects the health of the public from potentially communicable diseases, begins diagnostic and therapeutic interventions, and provides appropriate referral. Local or regional international health clinics are good resources for referral of patients who need more advanced evaluation, serologic testing, and long-term follow-up (see http://www.travelersvaccines.com/).
Key points for the initiation of ED care are the following:
Isolate and use personal protective precautions early when evaluating patients with suspected travel-related infections.
Most travelers do not have exotic diseases; think of common causes.
Malaria lurks in the febrile patient returning from travel, even in the presence of prophylaxis.
INITIAL EVALUATION OF THE RETURNING TRAVELER
Of travelers, 64% report one or more illnesses during travel, 26% are ill upon return, and 56% of those ill upon return develop symptoms after arrival in the United States.2 Many disease incubation times are longer than the transit times.
Most travelers on vacation or business are abroad for <20 days, and <5% spend extended time overseas. Some travelers originate from disease-endemic nations, as tourists or newly arrived immigrants; these people are at risk of illness due to transit and exposure to areas with high rates of endemic infectious disease. Others at risk include nonvoluntary travelers, such as refugees and displaced persons, as well as landed immigrants returning from visiting their homeland. In all extended-duration travelers, consider endemic illnesses, even if they lived in the area previously. Travelers also have a risk of tropical illness due to increasing adventure-type travel to areas that were previously inaccessible (Table 161-1).
TABLE 161-1Risk of Infectious Exposure |Favorite Table|Download (.pdf) TABLE 161-1 Risk of Infectious Exposure
|High risk (1 in 10 travelers): diarrhea, upper respiratory illness, and noninfectious illnesses such as injuries and exacerbation of preexisting chronic diseases |
|Moderate risk (1 in 200 travelers): dengue fever, Chikungunya, enteroviral infection, gastroenteritis, giardiasis, hepatitis A, malaria, salmonellosis, sexually transmitted diseases, shigellosis |
|Low risk (1 in 1000 travelers): amebiasis, ascariasis, measles, mumps, enterobiasis, scabies, tuberculosis, typhoid, hepatitis B |
|Very low risk (1 in >1000 travelers): human immunodeficiency virus, anthrax, Chagas' disease, hemorrhagic fevers, pertussis, plague, typhus, hookworm |
Diseases such as malaria are uncommon in the United States but are leading causes of mortality overseas. Other parasitic agents, such as helminths and rickettsia, also occur with increased frequency and severity in the tropics (see chapters 158 and 160, "Malaria" and "Zoonotic Infections"). Diagnosis of a tropical infection requires a unique set of tests, and therapy is organism specific.
Think of a potential bioterrorist agent as a cause of disease when factors suggest intentional release, such as divergence of the disease presentation from the typical epidemiology of the community and an atypical number of patients presenting with similar clinical syndromes. Examples of diseases that could be weaponized include anthrax, plague, viral hemorrhagic fevers, and tularemia (see chapters 9, "Bioterrorism" and 160).
The approximate incubation period (the time between exposure and signs and symptoms) can be helpful in assessing illness risk. For ...