Diseases Go Global
Diseases Go Global

According to one estimate, by the time of the European colonization of the Americas, plagues such as smallpox and measles could travel around the world within the span of a year. Today, of course, with international air travel, an infected person can carry a disease from almost any point of the globe to any other point in less than 36 hours.

One of the particularly threatening aspects of this compression of time is that people can now cross continents in periods of time shorter than the incubation periods of most diseases. This means that, in some cases, travelers can depart from their point of origin, arrive at their destination, and begin infecting people without even knowing that they are sick.

Source: Office of Travel and Tourism Industries (2011)

The new ease with which infectious diseases can be transmitted globally is having a direct and dramatic effect on morbidity and mortality around the world. Annually, an estimated 16 percent of all deaths worldwide result from infectious diseases (Center for Strategic and International Studies, n.d.).  Infectious diseases also account for 30 percent of all disability-adjusted life years (DALYs) worldwide, 1.5 billion total DALYs per year (one disability-adjusted life year is one lost year of healthy life); hence their impact is even larger (World Health Organization, 2004).

According to the United Health Foundation, within the United States, there has been a large percent decrease in the incidence of infectious disease between 1990 and 2010, dropping from about 40 percent to 17.5 percent (America’s Health Rankings, n.d.).   However, the World Health Report 2007 states that worldwide infectious diseases are currently spreading faster and emerging quicker than ever before: “Since the 1970s, new diseases have been identified at the unprecedented rate of one or more per year.” Climate change is facilitating this process, spreading diseases to regions where they were previously absent (International News Service, 2011).


Several new infectious diseases, including severe acute respiratory syndrome-associated coronavirus (SARS-CoV), henipaviruses (Hendra and Nipah), avian influenza virus, and the H1N1 virus (Swine influenza) are some of the newest diseases that have received much attention, due to their rapid spread around the world. Other historic, infectious diseases, such as West Nile fever, human monkeypox, dengue, tuberculosis, and malaria are reemerging as well.  Other well-known, historic infectious diseases, such as tuberculosis, are also unfortunately making a comeback; in the United Kingdom, which had almost completely eradicated tuberculosis from the British Isles by 1953, about 9,000 new cases of the disease are reported annually (Public Health England, n.d).

The dangers posed by these diseases go beyond simple medical concerns. In 2008, Pentagon Reports (Storming Media) issued a statement, describing the vast consequences of the global spread of infectious disease. The report asserted that:

The global community has suffered recently from newly emerged infectious diseases, including HIV/AIDS and severe acute respiratory syndrome (SARS), and from reemerging diseases once thought to be in decline. Additionally, it is increasingly recognized that infectious disease can pose a significant threat to U.S. and world security. To best understand and mitigate this threat, U.S. policy makers require adequate and timely information about the occurrence of infectious disease worldwide.

The threat of political instabilitywhich can be defined as war, ethnic conflict, and violent regime transitionis most likely to endanger developing countries. In these nations the burden of disease can strain already meager national budgets, set off competition for resources, and result in the death or disability of important government officials.

In many African countries in particular, the most skilled and wealthiest segments of the population are often the most likely to become affected by the HIV virus. This tends to be the case because the wealthier segments of the population are often more mobile and have more opportunities for sexual partners.

“….the concept of [domestic] as distinct from “international health” is outdated. Such a dichotomous concept is no longer germane to infectious diseases in an era in which commerce, travel ecologic change and population shifts are intertwined on a truly global scale.”

-U.S. CDC, “Addressing Emerging Infectious Disease Threats: A Prevention Strategy for the United States,” p . 12

Similarly, the armed forces of some African countries are estimated to harbor infection rates of between 10 and 60 percent. Losses of key military leaders and senior officers can lead to breakdowns in the chain of command, and make it more tempting for younger officers to launch coup attempts.

Of course, the problems of health and instability are not limited to Africa or to the HIV virus alone. Political instability is most likely to arise in the presence of broad social upheaval. A study by Ted Robert Gurr, et al. indicated that  “the causes of state instability in 127 cases over a 40-year period ending in 1996 suggests that infant mortality is a good indicator of the overall quality of life, which correlates strongly with political instability.” The National Intelligence Council evaluated all 127 cases for the presence of certain variables or indicators of social and political turmoil. Out of the 75 factors they analyzed, three factors proved to correlate the most significantly as predictors of political instability. These three most powerful determinants were:

  • incomplete democratization,
  • low openness to international trade
  • infant mortality

In particular, they found that high infant mortality within a state that is only partially democratic is most likely to produce instability.

Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, World Population Prospects: The 2010 Revision, http://esa.un.org/unpd/wpp/unpp/panel_population.htm

Questions for Discussion:

The aforementioned study on political instability found that incomplete democratization, low openness to international trade, and infant mortality are the three strongest predictors of political instability. Do you think these three predictors are related to each other? How?

Why does the spread of infectious disease lead to political instability?

If the spread of infectious disease has been around for centuries, why does it seem like this is a relatively new phenomenon? What do you think has drawn increased attention to global diseases?

Do you think there is a connection between infectious diseases and economic development?

* Picture Source: www.picapp.com



Next: Infectious Diseases and Global Public Health