As international travel has picked up, so too has the spread of travel-related infectious diseases and physicians' responsibility to more thoroughly investigate patients' travel plans and history during visits.
As many as 43% to 79% of travelers to low- and middle-income countries become ill with a travel-associated health problem, according to the 2024 edition of the Centers for Disease Control and Prevention’s (CDC's) Yellow Book, which provides international travelers and clinicians with expert guidance for safe and healthy travel abroad.
In 2024 alone, CDC issued multiple health advisories related, for example, to a new surge of Oropouche, human parvovirus, dengue, and meningococcal disease, among other infectious diseases.
Several viral, vector-borne, and respiratory illnesses present similar, nonspecific symptoms, so without questioning on travel, physicians may not accurately diagnose their patients, says Lubbock infectious disease specialist Scott Milton, MD, a member of the Texas Medical Assocation’s Committee on Infectious Diseases and Region I medical director for the Texas Department of State Health Services (DSHS).
“I remember seeing my neighbor 15 years ago who was sick with a fever, and she asked me to come by and look at her,” he said. “About 10 minutes into the conversation she casually mentioned that she had just got back from Costa Rica. She ended up having dengue.”
Missing travel-related information can harm the patient – as in the case of dengue or malaria – and lead to wider public health concerns, says Susan McLellan, MD, a fellow member of the Committee on Infectious Diseases who teaches at UTMB John Sealy School of Medicine in Galveston.
“Not only cases of significant diseases that are a risk for the patient have been missed, but also cases that represent a significant risk to the community have been missed because physicians didn’t think that travel history was that important or were [too casual] in collecting that travel history,” she said.
To help physicians conduct a thorough interview, CDC lists nine elements that comprise a complete travel history:
- History of present illness,
- Vector-borne disease precautions,
- Past medical history, and
- Additional familial/behavioral information
Physicians suspecting some diseases – like mpox – should ask about sexual activity as well, Dr. McLellan says.
Physicians commonly have little training in diseases not endemic to their region, and what they hear in the news may be confusing, Dr. McLellan adds. For this reason, keeping up with health alerts from CDC, DSHS, and local health authorities is crucial.
CDC posts travel health notices in four tiers of severity, from Level 1 advising normal precautions to Level 4 advising a total avoidance of travel. Currently, CDC has eight Level 2 notices and six Level 1 notices active.
Physicians also can help patients plan recommended counseling, vaccinations, and medicines for the region they’re visiting, among other precautions, Dr. Milton says.
CDC’s website on travel health also spells out steps to take before visiting a country.