Back when I used to have free time, I watched the VH1 show Best Week Ever, in which comedic panelists would go through the obscure news of the week and at the end decide who or what was having their 15 minutes of fame, their “best week ever”. My vote for this week would have to go to… drum roll please… syphilis. It has been featured in the Daily Sun, the most recent episode of House, and was featured in an article in the New York Times (http://www.nytimes.com/2008/04/29/health/29essa.html?_r=1&ref=science&oref=slogin). The recent buzz in Tompkins County about syphilis has put the disease in somewhat of an infamous spotlight, but the article deals more with the history and progression of the disease, which just so happens to relate to networks.

Syphilis, as it turns out, was not always a sexually transmitted disease. It was originally a disease of the skin around the time Europeans were just starting to explore South America. Against what was previously thought, the South Americans gave it to the Europeans, who then brought it back to Europe. The Europeans were not the ones who brought it to America. By introducing it, in the skin disease form, to Europe, this greatly expanded the number of people without resistance that were exposed to it. This increased exposure lead to a greater chance of a continuous outbreak.

While in Europe, syphilis mutated into a sexually transmitted disease. The weather conditions in Europe made it difficult for skin transmission so syphilis slowly mutated into a sexually transmitted disease so that it would not have to brave the elements. The problem with this was that at the time, symptoms included large foul-smelling boils. For transmission, the infected person would have to, umm, have sex. The strains of the disease where these visible symptoms were less noticeable or non-existent spread more rapidly, since no one in Europe wanted to sleep with someone who happened to have foul-smelling boils. This mutation allowed for the infected people to increase the number that would be exposed to the disease, furthering its self-preservation. As well as keeping the infected host reasonably similar in appearance, this strain also kept those infected from experiencing symptoms that would limit the possibility for sexual encounters.

So syphilis, through many generations and many mutations was able to adapt in the ways that would increase its reproductive number. Syphilis transformed into a sexual transmitted disease to increase its exposure probability. The syphilis around today has less visible symptoms so that the number of people exposed to it will remain higher than otherwise. Syphilis’ development from South American skin disease to worldwide sexually transmitted disease is possible by its unknowing use of network structure.