By: Kruti Yagnik, DO
It’s 1 am on a weeknight. You are a new first year fellow and your pager goes off. The ER physician calls to tell you that there is a patient in the emergency room who just returned from an international trip and is not feeling well. They are asking what labs and work-up they should start sending, and if any treatment is indicated.
Fever of unknown origin, especially in a returning traveler, is one of the most terrifying and exhilarating calls in ID. Though this can be a very scary, especially early on in your fellowship, it will give you an opportunity to flex your diagnostic muscles and reflect on diseases you may rarely get to see. Take a deep breath, stay calm, and realize that you are not alone. This would be a good time to call your attending or supervising doctor who is on service with you – remember, they are available 24/7 to help you. In the meantime, there is plenty of history to be obtained and workup to be started.
The evaluation of fever in a returning traveler includes a thorough clinical history: symptoms, time period of symptoms in relation to recent travel (taking into account incubation period of certain infections), activities while traveling (hiking, caves, water exposure, etc.), animal exposures, insect bites, food/water consumption and handling/preparation, and vaccinations and/or chemoprophylaxis taken before and during their trip. Many of these things will be obtained the next morning during your full consultation along with a thorough physical exam (including skin exam). However – it would be appropriate to ask the ER provider where the patient traveled to and when they returned, to see what the patient’s risk factors are.
There are two relatively important questions to determine at the time of the call. The first is, how sick is this patient? If the patient is very sick, it is worthwhile to go in person and evaluate the patient. For example, if the patient is very ill with suspected malaria, urgent evaluation of thick and thin smears is required. Further, an early call to the CDC Malaria hotline may be important in obtaining some treatments, such as artesunate.
A second critical question is whether or not the person needs to be isolated. Isolation should be considered in diseases such as Ebola, severe respiratory viruses, and diarrheal illness. When in doubt, place patient in isolation until thorough history can be obtained.
There are many excellent resources to help with the initial workup in a febrile returning traveler. The CDC Traveler’s Health website has a list of recommendations, such as vaccinations and prophylaxis, for travelers (by country). This can help to inform you what illnesses are considered endemic in the regions your patient recently traveled.
The recommend initial work-up/labs until are similar to non-travel related fever. You can start with complete blood count (CBC), complete metabolic panel (CMP) including liver function testing and kidney function, blood cultures, and urinalysis and culture. Based on clinical history, consider chest x-ray/CT chest, stool culture/multiplex PCR, stool ova/parasites exams, viral serology (if concerned for Dengue, Zika, Chikungunya, or other viruses), and acute hepatitis testing. A helpful figure is included below – this was obtained from an excellent review of fever in a returning traveler that was published in the New England Journal of Medicine.
Remember, Malaria is a medical and infectious disease emergency, and needs to be excluded! If patient has traveled to where malaria is endemic, always consider this in your differential. Malaria is diagnosed by visualizing parasites on a blood smear. You will need to contact your hospital’s laboratory to ensure this is done. Ask if somebody there is able to identify parasites (possibly a microbiologist or pathologist). When in doubt, you and your attending can also go in and look at the slide yourself. Treatment will depend on the parasite load and patient’s clinical presentation – so an appropriate diagnosis is key.
If malaria has been excluded, initiate targeted therapy based on the individual’s history, physical exam and results of testing. If the diagnosis is unclear and the patient remains stable, consider holding antibiotics as further workup is obtained. If the patient is ill or at risk for decompensation, early empiric antimicrobial management is recommended. The empiric regimen should consider most likely diagnoses. Empiric doxycycline can be added to regimens if there is concern for illnesses such as Rickettsia, leptospirosis, or other vector related bacterial infections.
Last Updated 7/18/2022