The following are three papers I wrote for this class. I received As on all of them. These were
moved from Google Docs, please excuse any formatting changes.
The Spread of Vector-Borne Diseases
In the public imagination, diseases that spread from person to person loom large:
Diseases like Ebola and SARS, spread through international travel, capture headlines and the
public imagination. It is true that globalization is causing diseases that might once have
appeared and then died out in small areas to threaten much larger populations. The SARS
epidemic, for example, originated in Vietnam, where it was diagnosed in February 2003 as an
atypical case of pneumonia, but by May that same year “30 countries on six continents had
reported a total of more than 7,000 probable cases with more than 500 deaths” (Pang). With
approximately one million people travel internationally every day and a similar number
travelling between developed and developing countries each week, “it is entirely possible that a
person in the early stages of an infectious disease could be halfway around the world in 12–15-
hours and thus function as a vector for that disease, aiding its spread, perhaps into vulnerable,
non-immune populations” (Pang).
With all the panic over fast-moving and exotic diseases, people neglect to see the
sinister impacts of more common diseases. Many of history’s deadliest diseases, such as Lyme,
malaria, and yellow fever, are vector-borne, that is, infections transmitted by the bite of infected
arthropod species, such as mosquitoes, ticks, triatomine bugs, sandflies, and blackflies (Vector-
borne Diseases, ECDPC). Vector-borne diseases account for 17% of all infectious diseases and
are responsible for over one billion cases and one million deaths annually (Vector-borne
Diseases, WHO). These diseases are re-emerging and spreading as a result of increasing
temperatures around the globe. Pathogens and vectors are small, simple organisms. They
generally do not have systems to regulate their body temperature or fluid levels (Patz). Lacking
the ability to adapt to different climates, these organisms thrive within a set of specific climatic
conditions, and are especially susceptible to changes in temperature, humidity, and rainfall
(Patz). Weather patterns and average temperatures determine the habitat sustainability,
distribution, abundance, biting rates, and reproduction of vectors.
In the past forty years, as the average temperature has increased 1.5 degrees Celsius,
Europe has seen a dramatic increase in density and geographic span of tick vectors (Lindgren).
Lyme borreliosis, the disease carried by ticks, is treatable by antibiotics but often goes
unrecognized and can lead to severe complications of the brain, heart, and joints (Lindgren).
Lyme borreliosis is now the most common vector-borne disease in Europe, with particularly
high incidence in Germany, Austria, the Czech Republic, and Slovenia. Although Sweden is not