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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 fourteenth-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 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—most recently in 2009—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.

Severe Acute Respiratory Syndrome

The 2003 outbreak of SARS has been well chronicled. This newly discovered pathogen was quickly spread by an infected traveler who left Guangdong Province, China, and arrived in Hong Kong, where he infected 10 other people staying in a hotel, leading directly or indirectly to cases in 8 countries. The combined influence of World Health Organization (WHO) travel advisories and media attention to SARS affected traveler behavior to the extent that tourist arrivals in East Asian airports dropped 41% from April 1 to April 21, 2003.

2009 Influenza A (H1N1)

In March 2009, a new strain of influenza A (H1N1) began spreading in Mexico. Within 30 days, cases occurred in US states bordering Mexico. Within 90 days, WHO declared that a pandemic, or global outbreak of H1N1 influenza, was occurring. Analysis of preliminary passenger volume data for the largest airline carriers between Mexico and the United States indicated that during April 27 through May 17, 2009, northbound volume dropped 42%, and southbound volume dropped 57%, compared with the previous year.


Modern travel and trade rely on global circumnavigation in <24 hours. Therefore, each new outbreak of disease has the potential to affect travelers and the travel industry. 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, because public health interventions are usually locally driven.

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 threats to health is low most of the time. When increased health screening occurs, it is usually consistent with the threat of an identified contagious disease with the potential for spread through travel. Below is a list of public health measures used internationally, ranked in order from the least to the most invasive, that may be used to detect or control infection in international travelers, depending on the situation:

  • Visual screening—observation of travelers conducted by customs or public health officers at ports of entry, typically without direct interaction with travelers, usually in place at all times
  • Health education for travelers—health communications intended to educate international travelers about a particular disease and border screening measures in place, including travel health alert notices or other printed material handed to travelers upon arrival, announcements or posters in transit areas, public service or social media announcements, and website information
  • Travel warning—a notice published by government health authorities advising people to avoid 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 travelers believed to have been potentially exposed to an infectious disease during travel, for the purpose of locating or providing information to the travelers
  • Traveler’s health declaration form—a form often considered a legal, signed document, similar to a customs declaration form, that is 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 evaluate symptoms and exposure history, to assess the risk of disease exposure or infection
  • Temperature check—measurement of a traveler’s temperature to identify a fever; can be done remotely by using a thermal imaging camera or through the use of a thermometer
  • Detention—holding in custody a traveler suspected of being infected with a communicable disease of concern, to allow further medical screening and examination by public health officials
  • 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 the transmissibility and severity of the disease in question.


Whether it is a person’s first international trip or that person is a 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 cancelations 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 travel schedules may be disrupted, 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, as occurred in the United States after September 11, 2001, and in the spring of 2010, when clouds of ash resulting from eruptions from Iceland’s Eyjafjallajökull volcano stalled air traffic over Europe. Although these instances were emergency disasters and not illness outbreaks, they demonstrate the sensitivity of air travel to health and safety threats.
  • 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 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 to or exit from a country during an infectious 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 oral or ear 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, such as nasal or throat swabs or blood tests
  • Be isolated from other people until they are determined to be noninfectious
  • Be hospitalized and given medical treatment if they test positive for or are otherwise diagnosed with an infectious 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 infectious or may have been exposed to a communicable disease of public health concern


The United States, acting through the Department of State, takes action to protect US citizens who are abroad via a number of diplomatic channels. However, 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 any traveler who appears to be infected with or exposed to a disease of public health concern. The ability of the Department of State to intervene in such situations is limited. In effect, if a person chooses to travel abroad, he or she should be aware of the potential for the complete disruption of his or her journey by an outbreak or epidemic of public health significance. Travelers should be up-to-date on routine vaccinations and receive any vaccinations or prophylaxis recommended or required for their destinations. CDC recommends that if a person is planning to travel internationally and feels ill or has symptoms such as fever, rash, or cough, he or she should consult with a medical provider and postpone travel until the illness or symptoms have resolved. Similarly, if a traveler becomes ill during or after international travel, he or she should seek medical attention and postpone further travel until the illness or symptoms have resolved. If an infectious disease is suspected, the traveler should call ahead before arriving at the medical facility, to avoid infecting other patients and staff.

Travelers can consult the embassies of the countries in their travel itineraries for information about health interventions and procedures that may affect their travel, although in some instances, inquiries or embassy websites do not provide correct or up-to-date information. 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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