Carrier of SARS Made Seven Flights Before Treatment

Globalization and Health

Newspaper article

By: Keith Bradsher

Date: April 10, 2003

Source: Keith Bradsher. "Carrier of SARS Made Seven Flights Before Treatment." New York Times (April 10, 2003): 5507, 1304-51.

About the Author: Keith Bradsher, the son of a Polk Award winning journalist and reporter for the Washington Star, was also the recipient of a George Polk Award for his series on the dangers posed by sport utility vehicles (SUVs). He was a finalist for the Pulitzer Prize in journalism and won the 2003 New York Public Library Helen Bernstein Book Award for Excellence in Journalism. Bradsher attended the University of North Carolina on a Morehead Scholarship. While he was in graduate school, earning a public policy master's degree from Princeton University's Woodrow Wilson School, he filed more than 140 business stories with the Los Angeles Times. He became a staff writer for the New York Times (NYT) in 1989, at the age of twenty-five. In 1996, he became the Detroit Bureau Chief for the NYT. It was in Chicago that he became involved with the automotive industry, and he began the series of stories on SUVs that spawned a book and much critical and professional acclaim, while also raising the ire of the industry. Bradsher was the Detroit Bureau Chief from 1996 to 2001, and has been the Hong Kong Bureau Chief for the NYT since 2001.

INTRODUCTION

Before the development of mass forms of transportation, the spread of diseases was relatively confined within geographic areas; humans could only spread disease among their immediate neighbors. Other transmission vectors, such as insects, rodents, and birds, were limited in their ability to cross vast open terrain (mountains, canyons, deserts, etc.) or large bodies of water. This provided a type of natural barrier for the distant spread of disease. Beginning with the early explorers and followed by trade and transport vessels, things began to change, as diseases were carried from one continent to another. Columbus and his sailing crews, for example, spread syphilis from the Old World to the New World.

With the advent of intercontinental air travel, the planet became one large global community. In this global community, diseases can be transmitted within a matter of hours, well within the incubation period of nearly every virus and bacterium.

Throughout recorded history, the spread of disease has been facilitated by vessels of transportation, as well as by large population movements. It is not uncommon for armies, which typically operate under crowded, stressful, and disease-prone conditions (lack of sleep, diminished sanitary conditions, foreign and unpredictable environmental conditions, irregular, and often, insufficient nutrition), to incubate communicable diseases within their ranks and spread them to the communities in which they are stationed during times of military conflict. Because armies (or other military groups) are mobile, it is easy for them to spread diseases common to one region to the population of another region that had been previously unaffected.

In early efforts to establish disease control and to prevent the spread of plagues, European countries established a period of forty days in which troops and ships, among others, were maintained outside of population areas in sanitary zones. This control mechanism was called quarantine (from the Latin root word quanta, meaning forty), and it was practiced from the first century CE through the seventeenth century.

With the development of steamship trade, followed by the development of large-scale railroad systems, the spread of disease beyond continental boundaries increased tremendously. Cholera outbreaks became epidemic. In an effort to develop cooperative means of preventing mass spread of disease, the First International Sanitary Conference was held in Paris in 1851. The concept of quarantine was deemed ineffective, and a decision was made to institute international standards regarding hygiene and sanitation for international commerce and transport. In 1907, the International Office of Public Health was established in Paris.

Management or elimination of disease spread by maritime shipments has long been a concern as well. Vectors, such as rats, mice, fleas, cockroaches, lice, bedbugs, flies, and mosquitoes, tend to be plentiful in waterfront, container, and port areas. Because rodents, insects, and vermin may access ships in port, it is necessary to maintain stringent vector control measures to suppress or prevent infestation during the time that ships are docked. Typically, shipping companies employ infestation and infection control officers who are charged with conducting frequent and thorough inspections of the ships, dock areas, and all shipping containers. There are three major risk areas for vector contamination of ships. In port, disease vectors have easy, direct access to ships. In addition, ports provide multiple entry points for disease vectors, since goods (and people) from all over the world move through them. Also, the movement of containers, the loading and unloading of food, and the direct handling of food in port areas, offer the potential for vector attraction or exposure. The second area of risk is posed by those aboard ships that are in passage. Ships typically have limited medical staff or facilities, rendering diagnosis and adequate treatment at sea quite difficult. Finally, the dense population on board a ship and the difficulty of isolating infection pose serious health risks for passengers and crew, as well as for those in the port areas where the ship docks.

During the first third of the twentieth century, the burgeoning use of transcontinental and international air travel raised new concerns about global disease transmission. The first sanitary convention concerned with air travel was held in 1933, using the existent international maritime laws of infection control as a model. The convention focused on developing and implementing means of medical inspection and control of disease transmission during air travel. It laid the foundation for the creation of the World Health Organization Committee on Hygiene and Sanitation in Aviation, the agency responsible for ensuring the safety of the world community by preventing the spread of disease via commercial or military air travel or transport.

Improvements in aircraft design have increased speeds and decreased travel times. As a result, an individual can move from virtually any population center on the globe to any other within twenty-four hours. This situation leads to a number of potentially disastrous health consequences. First, many types of disease-causing bacteria can live in a host for more than twenty-four hours before symptoms of an illness appear, increasing the likelihood of unwitting disease transmission. Second, an individual may have been exposed to an illness and may develop symptoms after arriving at his or her destination, thereby introducing the illness to a new location. Third, an individual may not feel sick, but may still be able to transmit the disease to others, thereby potentially infecting fellow passengers (as well as others once he arrives at his destination). Fourth, an actively sick individual can expose flight staff and fellow passengers, as well as individuals at his destination. In addition, insects are common disease vectors and may be inadvertently transported in luggage, cargo, or food.

The design of the current air traffic system facilitates disease transmission. Airlines operate largely on a "hub and spoke" system. In this system, passengers travel from their home airports to large, crowded "hub" airports. From the hub airports, they then travel to smaller "spoke" airports. Nearly every flight that moves inter- or transcontinentally has one or more intermediate stops, thereby increasing the potential for bacterial or disease exposure exponentially. Before ever reaching his or her final destination, an infected passenger has multiple opportunities to expose not only the passengers and crew on his/her own flight, but multiple passengers and flight crews moving through crowded airports. The worldwide movement of a number of specific diseases—penicillin-resistant gonorrhea, cholera, rubella, hemorrhagic fever, influenza, AIDS (in the United States), and, more recently, SARS—has been linked to, or facilitated by, air travel.

PRIMARY SOURCE

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SIGNIFICANCE

The Federal Aviation Administration estimates that, worldwide, more than 1.6 billion people travel by commercial air transportation every year. This statistic suggests that virtually any communicable disease can be moved from one region, country, or continent or another in less than twenty-four hours. Whether or not passengers traveling with a disease-carrying individual become sick varies according to: 1) the way in which the disease is transmitted (in sputum or mucosal secretion, by airborne particles in a sneeze or a cough, by skin to skin contact, or blood or other bodily fluid exchange); 2) the level of communicability of the disease (how easily it is passed from one person to another); and 3) the general health or level of hardiness of the persons who come into contact with the carrier.

The air on board jetliners is typically a mixture of filtered outside and recirculated air. It is not considered to be any more conducive to disease transmission than the air in any other crowded environment. The air circulation system on board the typical jet aircraft is quite sophisticated. The manner in which the air is filtered and exchanged with outside air provides for a total change of cabin air fifteen to twenty times every hour. The recirculated air passes through high-efficiency particulate air (HEPA) filters that trap bacteria, particulate matter, fungi, and most viruses. This degree of air filtering is far greater than that which occurs in most high occupancy office buildings. The major concern, therefore, is not disease spread within the aircraft itself, but the transmission of diseases from one region to another by infected individuals.

It is possible for a person with a highly contagious, active illness to transmit it to those sitting in close proximity. This risk increases with the length of the flight or with extended waiting on runways when the air circulation systems are turned off.

The potential for the outbreak and global transmission of avian influenza (bird flu) is of enormous concern to the World Health Organization (WHO). Avian flu has killed more than fifty people in Asia since 2003, where it is widespread in both birds and humans. The present strain of the virus, which causes an extremely severe respiratory disease associated with a high death rate in humans, is not capable of sustained human to human transmission. However, the WHO is investigating scenarios that might occur if the virus mutates into a more contagious form. Since people would have no immunity to this new form of the virus, there is the possibility that a global pandemic (an epidemic that occurs over a wide geographic area, crosses international boundaries, and affects a large number of individuals) could result.

The WHO has strongly suggested that all countries develop, or update, their internal influenza pandemic preparedness plans. Specifically, every country should be prepared to respond to a rapidly moving contagious disease and the vast socioeconomic disruptions that could result if large numbers of citizens are sick or dying. To minimize the risk of disease transmission—both from person to person and from region to region—the WHO also recommends that anyone who is actively sick not fly on commercial airlines.

The WHO administers the International Health Regulations (IHR). These regulations are the legal, global protocol to prevent the international spread of infectious diseases. They provide a single, unified, codified set of policies, procedures, and protocols for the prevention of pathogen transmission and are equally applicable to air, train, and maritime transport. The IHR, in force since 1969, underwent revisions and updates during 2004 and 2005, following intergovernmental negotiations attended by more than 150 countries.

The IHR provide an essential tool for facilitating and expediting the sharing of urgent, critical epidemiological information on the transboundary spread of communicable diseases. Among the goals of the revised regulations are: 1) bolstering the global community's collective defenses against the spread of infectious diseases; 2) increasing the efficiency of the WHO's outbreak alert and response protocols; 3) ensuring transmission of timely and accurate data concerning potential international public health concerns; and 4) providing all necessary direct technical assistance to outbreak affected areas.

The Global Outbreak Alert and Response Network (GOARN), with administrative oversight from the WHO, is a collaborative effort among hundreds of technical, health-related, and academic institutions. Its mission is to ensure the rapid pooling and deployment of technical resources for the purpose of swift identification, confirmation, and appropriate response to disease outbreaks of international import. GOARN combines the infrastructure and expertise of such diverse organizations as the International Federation of Red Cross and Red Crescent Societies, UNICEF, the U.N. High Commissioner for Refugees (UNHCR), the U.S. Centers for Disease Control and Prevention, and international medical, epidemiological, disease surveillance, and laboratory initiatives. GOARN provides technical assistance, leadership, and coordination on site (in the field), while continuously transmitting information to the international community concerning the international outbreak threat level. The overall goals of GOARN include global disease surveillance, immediate reporting, and effective containment of outbreaks in order to prevent an international pandemic. It is critical that local, state, industry, and international agencies cooperate and collaborate in order to minimize threats to public health.

FURTHER RESOURCES

Books

DeHart, Roy L., ed. Fundamentals of Aerospace Medicine. Philadelphia: Lea and Febinger, 1985.

Last, John M., ed. Maxcy-Rosenau Public Health and Preventive Medicine. New York: Appleton-Century-Crofts, 1980.

Web sites

BBC News. "Air Travel 'Fuelled SARS Spread'." 〈http://news.bbc.co.uk/2/hi/asia-pacific/3329483.stm〉 (accessed October 27, 2005).

Disease/Infection News. "Better Air Onboard Reduces Spread of Disease on Aircrafts." 〈http://www.news-medical.net/print_article.asp?id=8352〉 (accessed October 27, 2005).

Journal of Multicultural Nursing and Health. "The Role of Aircraft in the International Transmission of Disease." 〈http://www.findarticles.com/p/articles/mi_qa3919/is_200001/ai_n8896335〉 (accessed October 27, 2005).

News Target.com. "U.S. Health Agencies Working to Deal With Diseases Spread by Air Travel." 〈http://www.newstarget.com/006872.html〉 (accessed October 27, 2005).

Preventing Pandemics. "Federal Health and Airline Officials Outline New Cooperative Efforts to Prevent Spread of Infectious Diseases on Commercial Air Travel." 〈http://www.house.gov/transportation/press/press2005/release29.html〉 (accessed October 27, 2005).

UCLA School of Public Health, Department of Epidemiology. "A Germ Has a Ticket to Ride, and Airlines Can't Stop It." 〈http://www.ph.ucla.edu/EPI/bioter/germhasticket.html〉 (accessed October 27, 2005).