Author(s): David Shlim

Travel medicine is based on the concept of risk reduction. In the context of travel medicine, “risk” refers to the possibility of harm occurring during a trip. Some risks are avoidable, while others are not. For example, vaccine-preventable diseases can be mostly avoided, depending on the protective efficacy of the vaccine. Perception of risk is a subjective evaluation of whether a risk is considered large or small; is 1 in 10,000 a large risk or a small risk? Tolerance refers to acknowledging a risk and accepting it; a risk of 1 in 100,000 might be tolerable for one traveler but not for another. The overall perception of risk is based on a combination of likelihood and severity. A low likelihood of a severe and untreatable disease might be perceived as more important than the greater likelihood of a less severe disease.

The rates of diseases (e.g., typhoid fever, malaria, Japanese encephalitis [JE]) in a particular country or location might not suffice for clinicians or travelers to make an individualized decision. Disease risks can range from 1 in 500 (an estimate of the risk for typhoid fever in unvaccinated travelers to Nepal) to 1 in 1,000,000 (an estimate of the risk for JE in travelers to Asia), and travelers need to determine what these statistics mean to them. Additional information to help make an informed decision should, most importantly, include the severity of the disease, how readily the disease can be treated, and the length and type of travel. For example, the disease risks encountered by high-end African safari goers might be quite different than the disease risks for people going to work in resource-poor areas of the same countries.

Even when risk is low, travelers’ decisions will still reflect their perception and tolerance of risk. When told that the risk for JE is 1 in 1,000,000, one traveler might reply, “Then I guess I don’t have to worry about it,” while another might say, “That 1 will be me!” Each traveler will have their own ideas about the risks, benefits, and costs of vaccines and drug prophylaxis; clinicians should discuss these with travelers in detail, with the goal of shared decision-making.

Perception and tolerance of risk are connected to the concept of commitment, particularly in regard to remote, adventurous travel. Commitment refers to the fact that certain parts of a journey might not easily be reversed once entered upon. For example, a traveler trekking into a remote area might need to accept that rescue, if available at all, could be delayed for days. A traveler who has a myocardial infarction in a country with no advanced cardiac services might have a difficult time obtaining definitive medical care. If the traveler has already contemplated and accepted this commitment, they can more appropriately prepare to deal with health concerns if they occur.

The goal of travel medicine should be to help travelers assess the various risks they could face and then educate them on how to manage and minimize, rather than try to eliminate, those risks. Travel medicine practitioners should discuss available risk statistics and discern the traveler’s perception and tolerance of risk, including their concerns about the risks from vaccines and prophylactic medications. Once this is done, the provider can then help travelers find their individual comfort level when making decisions about destinations, activities, and prevention measures.

Coronavirus disease 2019 (COVID-19) has had a profound impact on travelers’ perception of risk. Every aspect of travel is now colored by the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), from the mixing of travelers on the journey itself, to destination accommodations and dining venues, to recreation and tourism activities. In addition, now, more than ever before, individual travelers are confronting and addressing their role as potential conduits for the global spread of disease; to minimize the risk of COVID-19 transmission to others, responsible travel currently entails (at a minimum) pretravel vaccination, a negative COVID-19 test result, and posttravel quarantine. The constantly shifting landscape, unprecedented in travel medicine, has upended our understanding and perception of risk. Figuring out whether travel is even safe or wise has become the most prominent decision people must now make, with no easy answers. What is true one week can be completely different a week later.

Risk perception, as it relates to travel in the era of COVID-19, is twofold: the risk of acquiring the disease while traveling, and the risk of being stranded by sudden lockdowns, quarantine, and flight cancellations. Travelers now have to weigh all of these issues well in advance, when planning for the typical overseas journey starts, and try to make guesses about the situation that could exist months into the future. As travel medicine providers, the best guidance we can give to travelers is to refer them to reliable resources of information about the latest conditions at their destination and help them remain flexible and willing to cancel their trip, even at the last moment, if or when the situation at the destination begins to worsen.

. . . perspectives chapters supplement the clinical guidance in this book with additional content, context, and expert opinion. The views expressed do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).