The Geography of Transport Systems
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Days Required to Circumnavigate the Globe
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Impacts of Transportation on the Velocity and Extent of a Pandemic
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Diffusion of a Pandemic Through a Global Transportation Network
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Major Commercial Actors in Freight Distribution
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Dedicated Maritime Container Terminals Controlled By Major Port Holdings, 2007
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World's Major Container Ports, 2005
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NAFTA Transborder Truck Flows and Traffic at US Ports of Entry, 2002
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Map
Transportation and Pandemics
Dr. Luke: Department of Virology, Naval Medical Research Center. Dr. Osterholm: Director of the Center for Infectious Disease Research and Policy (CIDRAP), University of Minnesota.
1. Pandemics
There are approximately 1,500 microbes that are known to be a source of disease among the human population. Influenza is the most virulent among them because of its lethality and how easy it is to be transmitted. Under normal circumstances, influenza's impacts are relatively benign since populations have developed a level of immunity to its debilitating effects. Yet, it is estimated that between 1 to 1.5 million people per year die of influenza or related complications. Influenza pandemics are thus considered to be among the most significant threats to the welfare of the global population.
Pandemic. An epidemic of infectious disease that spreads through human populations across a large area, even worldwide.
Over the last 300 years, ten major influenza pandemics have occurred. The 1918 pandemic (Spanish Flu) is considered to be yet the most severe. 30% of the world’s population became ill and between 50 and 100 million died. One important factor why the Spanish Flu spread so quickly and so extensively was through modern transportation, which at the beginning of the 20th century offered a global coverage. The virus was spread around the world by infected crews and passengers of ships and trains and severe epidemics occurred in shipyards and railway personnel.
Concerns about the emergence of a new pandemic are salient, particularly in light of recent outbreaks such as SARS (Severe Acute Respiratory Syndrome) in 2002-2003, which quickly spread because of the convenience of air travel. The next influenza pandemic could be equally severe and widespread illness or absenteeism in freight transportation sectors can cause cascading disruptions of social and economic systems.
The relationships between transportation and pandemics involves two major sequential dimensions:
2. Vectors and Velocities
The more efficient transportation, the more efficient the vector that can transmit an infectious disease. International and long distance transport such as air and rail, modes and terminals alike, concentrates passengers and increase the risk of exposure. In the past, this could be an advantage as a ship could be quarantined, since there were ample time during the voyage for an infection to carry its course and the symptoms to become apparent. Today, it is a different matter as the velocity conferred by transportation systems for long distance travel is superior to incubation time of many flu variants (the period after the infection before symptoms are revealed). Since the incubation time for the average influenza virus is between 1 and 4 days, there is ample time for someone being infected to travel to the other side of the world before noticing symptoms.
Once symptoms have developed, there is also a "denial phase" where an infected individual will continue traveling, particularly if going back to his place of origin. An infected individual beginning to show symptoms is likely to cancel an outbound travel, but will do the utmost, even breaking quarantine (or warnings), to go back home. Thus, in a window of a few days before an outbreak could become apparent to global health authorities, a virus could have easily been transposed in many different locations around the world. At this point, the vector and velocity of modern transport system would insure that an epidemic becomes a pandemic. In some cases, the velocity of global transportation systems is higher than at the regional level, which paradoxically implies that a virus can spread faster at the global level - between major gateways - than at the regional level.
Once an outbreak becomes apparent, the global passenger transportation system, such as air travel and passenger rail, can quickly be shut down in whole or in part, either voluntarily (more likely if the outbreak is judged to be serious) or by the unwillingness of passengers to be exposed to risks. The later is what happened during the SARS outbreak in 2003. For instance, while the public transportation systems of several large Chinese cities were still operated, the number of users precipitously dropped because of risk avoidance. The SARS outbreak also had a substantial impact on the global airline industry. After the disease hit, flights in Pacific Asia decreased by 45% from the year before. During the outbreak, the number of flights between Hong Kong and the United States fell 69%. It is quite clear that this impact would pale in comparison to that of a 12 to 36 month worldwide influenza pandemic.
3. Continuity of Freight Distribution
However dramatic the impacts of modern transportation as a high velocity vector for a pandemic, a potential greater risk resides in the geographical and functional structure of supply chains because the continuity of freight distribution could be compromised. Up to the mid 20th century, the scale of production, transport and retail was dominantly local (food) or regional (durable goods such as cars). Since then, a process of globalization expanded substantially the scale at which a wide array of goods are distributed. Thus, the interconnectedness of the global economy, while being a net advantage from a supply chain standpoint, could make the next influenza pandemic more devastating than the ones before it. Even the slightest disruption in the availability of parts, finished goods, workers, electricity, water, and petroleum could bring many aspects of contemporary life to a halt. The global economy has been favored by the exploitation of comparative advantages and a more tight management of supply chains. Inventories are kept to a minimum. Virtually no production surge capacity exists. As a consequence, most markets depends on the the timely delivery of many critical products (such as pharmaceuticals, medical supplies, food, and equipment parts) and services (such as communications support).
The transportation industry has also consolidated into a small number of global and national mega-players to achieve massive economies of scale. Since the frequency, speed and reliability of shipments are high under normal circumstances, manufacturers have relocated their facilities to lower cost locations. Because transportation costs are lower than inventory management costs, retailers and secondary manufacturers employ “just-in-time” inventory systems - their “stockpile” is flowing in the transportation stream as inventory in transit. Most supply chains are re-stocked on a continuous basis, on par with the demand. The typical efficiency, and potential non-resiliency, of critical supply chains as a function of transportation would be placed under stress during a pandemic. The most important include:
It is very likely that a pandemic would quickly exhaust available food, energy and medical resources, replacements will not be forthcoming. Thus, supply chain issues are expected to seriously compound the impacts of an influenza pandemic.
4. Possible Mitigation Strategies
Many pandemic preparation plans fail to account the full importance and ramifications of global supply chains. They are essentially designed with the assumption that national economies, namely the United States, are mostly self reliant. The geographic and functional realities of the global economy are quite different from this assumption. Cascading disruptions in vulnerable freight transportation systems and strategic supply chains can compound the difficulties of maintaining social cohesion and critical infrastructures during a pandemic. Transportation workers must therefore receive a high priority for support – including vaccine, prophylactic antivirals, public health interventions and access to health care. Pandemic planners must cooperatively develop plans and obtain the agreements and resources necessary to conduct health assurance campaigns at major transportation chokepoints and corridors.
The basic strategy to protect the transportation system is to provide the workers with vaccine, prophylactic medications, protective equipment and physical security under the umbrella of transmission shielding operations as they move from and into transportation chokepoints and at suitable points along major corridors (i.e., weigh stations, etc). Transportation workers must also have a well-enunciated priority for healthcare services if they become ill during their work travels. This will require that some national, state and local pandemic resources and response activities are reprioritized from traditional influenza priority groups (elderly, etc) to insure that all citizens have a reliably adequate supply of essential supplies and services. Using modern communication systems, national, state and local licensing and regulatory authorities, industry and unions can identify, locate, educate and train the transportation workforce. Governments and transportation stakeholders (industry, unions, and workers) must create a cooperative plan that identifies roles, resources and responsibilities.
Because transportation workers must cross international and local borders, national and local entities, industry and unions, health agencies and other stakeholders must provide this support without regard to their nationality or state of origin. The international maritime domain presents unique challenges as it plays a fundamental role in supporting the global distribution of essential commodities (food and energy), parts and finished goods. The naval services of nations should prepare to establish task forces in international waters to quickly provide vaccine/antivirals and other health assistance to the multinational mariners of commercial vessels as they transit into or out of maritime chokepoints and sea lanes. International entities such as the North Atlantic Treaty Organization, the International Maritime Organization, or the Global Maritime Partnership initiative, can provide the organizational framework to protect global maritime commerce.
07/29/08