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Chapter 6 Conveyance & Transportation Issues

Perspectives: What to Expect when Traveling during an International Outbreak

Todd W. Wilson, Nicole J. Cohen


Outbreaks of communicable diseases have occurred throughout history, dramatically shaping the human experience. One of the most recognizable examples of an outbreak with terrible consequences for both human health and culture was the 14th-century plague epidemic, or “Black Death,” thought to have been caused by Yersinia pestis, which killed up to 60% of Europe’s population and also spread to Asia and Africa, possibly reducing the global population by 17%.

In recent times, diseases such as Middle East respiratory syndrome (MERS), Ebola virus disease, and severe acute respiratory syndrome (SARS) have appeared, seemingly from nowhere, and resulted in high numbers of deaths and illness among those infected. And throughout history new strains of influenza have emerged, circled the globe, and caused social disruption and economic upheaval. These diseases and others like them, which emerge, spread rapidly via travel across international borders, and have serious or initially unknown health effects, have led countries to take public health measures at borders that affect travelers.


When disease threats emerge, countries may take border measures that range from minimal to invasive, regardless of available evidence of the efficacy of those measures. These interventions vary between and within countries and can change rapidly without official notification to the public.

To understand what to expect during an emergency, it is important to know that health screening of travelers is always in place at international ports of entry into most countries. Usually, the form of screening is minimal and routine, since the risk for major health threats is low most of the time. Emergence of a contagious disease with the potential for spread through travel may lead to enhanced screening and the implementation of control measures when potentially infected travelers are identified. Below is a list of public health measures, ranked in order from the least to the most invasive, that may be used internationally to detect or control infection in travelers, depending on the situation:

  • Visual screening—observation of travelers for signs of illness, typically without direct interaction with travelers, usually in place at all times
  • Health education for travelers—health communications (such as printed material handed to travelers, announcements or posted messages in transit areas, or use of social media or websites) intended to educate international travelers about a particular disease, recommended actions, and border screening measures in place
  • Travel warning—a notice published by government health authorities advising people to avoid nonessential travel to an area where a disease outbreak has been identified
  • Passenger locator form—a form used by health officials to gather contact information for potentially exposed travelers, for the purpose of locating the travelers for evaluation or to provide information
  • Traveler’s health declaration form—a form used by customs or health officials at ports of entry to gather information related to a traveler’s health, prior itinerary, and exposure to infection
  • Direct questioning—interview of travelers by customs or health officials to assess the risk of disease exposure or infection
  • Fever screening—measurement of travelers’ temperatures, either remotely by using thermal imaging cameras or through use of thermometers
  • Detention—holding in custody a traveler suspected of being infected with a communicable disease of concern, to allow further medical evaluation
  • Isolation—separating and restricting the movement of an ill person who has a communicable disease of concern from those who are healthy, to minimize disease spread by preventing further transmission
  • Quarantine—separating and restricting the movement of people who are well but may have been exposed to a communicable disease, to monitor their health and prevent possible transmission to others, until it is determined that they are not infected

Ultimately, for a given outbreak, the decision on which health measures to use, and how extensively each measure is implemented, will depend on a number of factors, including the transmissibility and severity of the disease in question, local customs, and governmental public health regulations and policies.


Whether a person is a first-time or seasoned international traveler, chances are he or she has planned the itinerary carefully to make the trip an enjoyable travel experience. Factoring in some amount of risk and being aware of as many chance variables as possible can help mitigate some of the negative repercussions, should an outbreak of illness occur that impacts travel. The following situations have been observed in nearly all international outbreaks of disease during the modern travel era since the 1960s:

  • Travel delays—Travel into, out of, or within certain regions may be affected by border health measures or behavior of travelers.
  • Inconsistent information—Early in an outbreak, information may change rapidly, be conflicting, or later be determined to be incorrect, while governments, health officials, and the travel industry work to define the situation and provide reliable information.
  • Canceled flights, ship voyages, trains, buses, or routes—Travel cancellations can occur suddenly, especially for air travel, which can be particularly sensitive to shifts in passenger demand and is often unpredictable during outbreaks.
  • Voluntary cessation of travel—Travelers may choose to postpone their travel because of official travel warnings, travel advisories, or concerns about their health, border measures, or the possibility of being stranded in a foreign country. Large decreases in travel volume can decrease travel options and disrupt travel schedules, especially to and from the countries most affected by the outbreak.
  • Increase in travel—People traveling in affected countries in the early stages of an emerging outbreak may seek unplanned return journeys, as people try to avoid infection or seek health care in their home countries.
  • Grounding of flights—In extreme circumstances, flights may be unavailable in a region for a period of time.
  • Entry or exit screening—The set of border health measures described earlier in this section may be applied, in whole or in part, at international borders, either to prevent the introduction of infection into the country (entry screening) or to prevent infected people from leaving and spreading infection to other countries (exit screening).

Guidelines and practices for what governments ask of travelers on arrival or exit may differ markedly from country to country. Some countries maintain national control over all ports of entry and exit, while in other countries such control is delegated to state, provincial, or local authorities. In either case, requirements and procedures may differ widely and change over time. Flexibility, honesty, and compliance are essential to a successful interaction with public health and other government officials during international travel.

Below is a list of actions travelers might experience upon arrival in or exit from a country during a communicable disease outbreak. This list is not comprehensive or exhaustive. Travelers may be asked or forced to comply with ≥1 of the following:

  • Have their temperatures taken either by thermal imaging camera or thermometer
  • Provide personal contact information and details about their travel itineraries
  • Respond to questions regarding symptoms of illness or exposure to ill people
  • Undergo a medical evaluation for infection, including diagnostic testing
  • Be isolated from other people until they are determined to be noncontagious
  • Be hospitalized and given medical treatment if they test positive for or are otherwise diagnosed with a communicable disease of public health concern
  • Be quarantined for a specified period of time if they were exposed to someone who is suspected or confirmed to be infected
  • Monitor their health during and after travel and report any symptoms they develop to health officials
  • Forego communications with family, friends, or traveling companions for a certain period
  • Be denied boarding on an airplane, ship, bus, or train, if it is determined they are contagious or may have been exposed to a communicable disease of public health concern


In the event of an outbreak or epidemic, any country has the right to enact measures to protect its citizens from ill travelers entering its borders or to protect global health from ill travelers exiting the country. These border measures may infringe on the individual rights of travelers. The ability of the US Department of State to intervene in such situations is limited.

Travelers can consult the embassies of the countries in their travel itineraries for information about health interventions and procedures that may affect their travel and for instructions on how to deal with being questioned by host country government officials regarding health or other issues. The Department of State website may be helpful ( Up-to-date information regarding infectious disease risks related to travel may be found at the CDC website ( Finally, because of the potential for delays and unexpected costs arising from an outbreak of communicable disease, CDC strongly recommends that travelers consider purchasing travel insurance to cover possible trip cancellations, requirements for health care abroad, or possible emergency medical evacuations (see Chapter 2, Travel Insurance, Travel Health Insurance, & Medical Evacuation Insurance).


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Perspectives sections are written as editorial discussions aiming to add depth and clinical perspective to the official recommendations contained in the book. The views and opinions expressed in this section are those of the author and do not necessarily represent the official position of CDC.