Published by EH.Net (May 2013)

Mark Harrison, Contagion: How Commerce Has Spread Disease. New Haven, CT: Yale University Press, 2012. xviii + 376 pp. $38 (hardcover), ISBN: 978-0-300-12357-9.

Reviewed for EH.Net by Philip R. P. Coelho, Department of Economics, Ball State University.

Contagion is a good book whose subtitle, ?How Commerce Has Spread Disease,? is somewhat misleading. The author, Mark Harrison, focuses upon: 1) the political reaction to contagious diseases, 2) an extensive history of quarantines, and 3) the commercial and medical foundations of quarantines. So the book is not so much about how commerce affected the spread of disease, but, instead, how the spread of disease affected commerce through quarantines. The book has nine chapters, a preface/introduction, and a conclusion. It is well documented with extensive notes and bibliography, and a useful index.??? ??? ???

The book is essentially: 1) a chronology of the contagious diseases that afflicted the (western) world from the medieval period to the present; 2) an historical analysis of diseases and the diverse social and political reactions they caused; 3) the history of the development of quarantines and their spread; and 4) the political and economic usage of quarantines as both part of geopolitical statecraft and as competitive tools for producers/merchants who used them to afflict their domestic and foreign rivals. The preface has an accurate summary of Harrison?s thesis: ?Each major outbreak of disease elicits a rash of hasty and opportunistic intervention intended to gain economic advantage as much as to protect health. … Quarantines have become tariffs by another name and the disputes they are apt to generate constitute a persistent and serious threat to global trade? (p. xiii).

Chapter one is an overview of the spread of various diseases from the fourteenth century through the mid-nineteenth. In fourteenth century European folk medicine epidemics were associated with long distance trade; Harrison describes Europeans refusing to purchase imported spices during the Plagues of the fourteenth century because they feared that disease could be contracted from them (pp. 3-4). Quarantines (the term was derived from the forty-day isolation of ships suspected of carrying disease) became widespread with the onslaught of the Plagues. Physicians, however, were slow to accept the association of commerce and contagion because it violated the classical theory that diseases were caused by an imbalance of ?humours? (blood, black bile, yellow bile, and phlegm). But experience and popular opinions eventually swayed the learned physicians into accepting that contagions could be separate from an imbalance of ?humours.? In the summary of the history of the spread of diseases Harrison has an error (p. 17): dating the beginning of the population implosion of the aboriginal peoples of the New World at 1518. The aboriginal population of the Caribbean started imploding at least as early as Columbus?s second expedition to the New World (1493-94). Francisco Guerra (1988) has a description and chronology of the population decline on Hispaniola. Guerra believes the initial epidemics and mortality were caused by influenza; regardless, Harrison is off by a quarter of a century in dating the beginnings of the massive depopulation of the Americas. The population implosion of the Americas predated the introduction of the first smallpox epidemic (1518) by decades.???
The book is quite good (and interesting) in explaining the reactions to epidemics and quarantines. Early on in the introduction of quarantines, there was lobbying by the providers of warehousing (for goods) and of food and lodging (for the humans) for quarantines of longer durations, irrespective of their efficacy.? Similarly whenever an epidemic broke out in foreign lands, chances were that providers of domestic substitutes would petition the political authorities for the establishment of quarantines. Conversely importers would resist the imposition of quarantines, and, when imposed, would petition for their early removal. All parties produced their own experts on public health and commerce in support of their positions; the more things change, the more they remain the same.

Politicians utilized quarantines in statecraft; sometimes establishing quarantines in tit-for-tat exchanges, at other times for weakening potential or actual foes, or assisting friendly powers and, at all times, seeking commercial advantage for their power base. The popularity of quarantines waxed and waned with the time and fashion. Colonial American authorities used quarantines ?to protect American ports from outbreaks of yellow fever in the Caribbean? (p. 52), earning the enmity of Benjamin Rush (among others) who identified quarantines with colonial oppression. With American independence Federalists generally supported quarantines while Jeffersonian Republicans opposed them. Their efficacy was a topic for political debate which often obscured any real data available to the early scientific establishment. Still, yellow fever was a killer and a frequent visitor to populations residing in places where it was not endemic in both the Old and New Worlds in the nineteenth century. Harrison has an extensive discussion of yellow fever; this discussion highlights both the strengths and weaknesses of Contagion.

The HMS Eclair was a British naval steamship sent to the West African coast in late 1844 to join in the suppression of the slave trade; it returned to England in September of 1845 with ?less than a third of her original crew? (p. 80). The Eclair?s crew had contracted yellow fever in Africa and had subsequently spread it to Boa Vista in Cape Verde where it ravaged the Cape Verdean population. The Eclair went on to Madeira where the governor refused her permission to land (he had been informed of the Cape Verdean epidemic).? The ship limped home all the while picking up volunteers to assist in manning the ship, and giving them yellow fever in return. The ship was a literal floating pest house. The British public was scandalized by both the death rate and the unwillingness of foreign ports to give succor to the Eclair.? Because yellow fever is only transmitted by mosquitoes (its most common vector is Aedes aegypti), the Eclair had to have carried its mosquitoes with it in order to infect newly boarded crew. Where were these mosquitoes breeding: was it in the bilge, the drinking water, the water used for making steam, or some combination?? Harrison rightly emphasizes that the reduced voyage times enabled by steam power aided in the transmission of yellow fever (an omission in his bibliography is Island Epidemics (2000), which has an intensive examination of the relationship between the speed of transport and the transmission of diseases). Harrison is neither interested in the etiology of diseases, nor how it affects their transmission.? Similarly Harrison notes (p. 85) in passing that the Africans employed on the Eclair (called Kroomen) were unaffected by the disease. I would like to have seen a greater examination of both the disease ecologies of steamships (did these ships have mosquitoes because they needed water to produce steam?) and the relative resistance to diseases of people of different ethnicities.
Still these are not Harrison?s interests. His interests are in quarantines; their politics, history, rent-seeking, and the other measures constructed under the rubric of public health that affected trade and commerce. It is a fine book given these boundaries. Anyone interested in the history and politics of quarantines should read and consult this book.


Andrew Cliff, Peter Haggett, and Matthew Smallman-Raynor (2000) Island Epidemics, Oxford: Oxford University Press.

Francisco Guerra (1988) ?The Earliest American Epidemic: The Influenza of 1493,? Social Science History 12 (3): 305?25.

Philip R. P. Coelho is Professor of Economics at Ball State University. His recent book (co-authored with Robert A. McGuire), Parasites, Pathogens, and Progress (MIT Press 2011), is a study of the impact of diseases on history with an emphasis on their impact on American slavery, and their role in the development of the Malthusian Doctrine. He continues to work on the impact of morbid diseases on economic productivity, the impact of evolutionary dynamics in economics, the economics of education and ethics.

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