DNA testing strikes again, but where was the historian?

Recently in Douai, Northern France, a group of 12 multiple burials and 4 single burials were tested for typhus based on their dental pulp. The mass grave was first discovered in 1981 during building construction, and were part of a salvage excavation. The 21 burials had no visible signs of trauma, they were positioned throughout the grave randomly head to foot. This suggests that the burials were due to epidemic disease. The burials are dated to the 18th century, and consist of only young males, likely related to military functions. In order to figure out what pathogen affected these individuals, their dental pulp was assessed by Nguyen-Hien et al. 2010.

Of the burials, 21 individuals were selected for testing. 55 teeth were taken, and their dental pulp was tested for pathogens by the CNRS and the Université de la Méditerranée. They tested for anthrax, louse borne fever, trench fever, typhus, typhoid fever, smallpox and bubonic plague. The 55 teeth from Douai had their DNA tested and the sequences were compared against the DNA from 1192 teeth that carried each of the seven pathogens. Typhus was present in 6 of the 21 individuals. They argue that this means that typhus was likely transmitted to the city of Douai through lice during a Spanish siege. This is further supported by genotyping of the DNA which showed that the variety of typhus is that which is most found in Spanish communities. Nguyen-Hien et al. 2010 conclude that it was likely brought to Douai from the Spanish during the 1710-1712 War of Spanish Succession, and prior to this was brought over by the conquistadors from America (Science Daily 2010).

The first appearance of typhus was noted by Thucydides in 430 B.C. in an account of the Pelopponesian war, and he attributed it to the downfall of Athens. The earliest definitive record is when it was epidemic among 1489 among the Spaniards when Isabella and Ferdinand waged war against the Moors. It killed over 1/2 of the soldiers. The disease followed the war as Spain fought against France throughout the 16th century. The disease continued to circulate, during the 30 years war in the 17th century between Germany and Sweden, and spread to England as they joined the battle (Conlon).

The question is then, why is the typhus outbreak in Douai attributed to Spainish conquistadors?

History aside, having a method for diagnosing these types of pathogens that does not result in major bone loss or destruction is important. Like the DNA tracking of the bubonic plague mentioned in the last post, this method fills in more information about the spread of disease.

However, as diseases spread and become endemic to an area, we must begin to question how these populations are reacting to them and how this will affect the spread of the disease. Why is it that after hundreds of years of being virulent in Europe, during a period when typhus was less prevalent, this village was affected? Why was only a small number affected? Consider the article recently released about the effects of urbanization on viruses, and changes in the immune system by Kaplan 2010 in National Geographic (Early Cities Spurred Evolution of Immune System).

Works Cited

Nguyen-Hien et al. 2010. Evidence of a Louse-Borne Outbreak Involving Typhus in Douai, 1710-1712 during the War of Spanish Succession. In PloS ONE, doi:10.1371/journal.pone.0015405, 27 October 2010.

Science Daily 2010. Skeletons from the 18th century reveal typhus epidemic from Spain. ScienceDaily. Retrieved November 11, 2010, from http://www.sciencedaily.com­ /releases/2010/11/101109095714.htm

Conlon. Historical Impact of Epidemic Typhus. http://entomology.montana.edu/historybug/typhus-conlon.pdf

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