Historic pandemics in Gibraltar may teach about health and disease
by Eleni Kanavas
With the H1N1 virus affecting the health of hundreds of people worldwide, the topic of pandemic diseases is generating a great deal of attention in the media and in health care circles recently.
But here at U of T Scarborough, anthropology professor and epidemic expert Larry Sawchuk has been studying pandemics for more than 30 years, long before the outbreaks of SARS, the Norwalk virus, and the H1N1 virus commonly known as swine flu.
In a recent article in the American Journal of Physical Anthropology, Sawchuk examines the impact of the 1918 influenza pandemic and mortality rates in Gibraltar. The piece is called “Brief Communication: Rethinking the Impact of the 1918 Influenza Pandemic on Sex Differentials in Mortality.”
For more than three decades, Sawchuk has been focused on the study of epidemics in Gibraltar, a British colony on the southern end of Europe’s Iberian Peninsula with a population of 30,000 people. “The Rock,” as it is colloquially known, has been infected over the years with such deadly diseases as yellow fever, cholera and influenza.
“A lot of my research stems from diseases like influenza and tuberculosis, where you can make some broad generalizations,” Sawchuk said. “But how a disease affects individual populations is extremely problematic. It’s probably impossible to generalize about the impact of an epidemic on any one population and extrapolate that to all other populations.”
While his research is historical, it may also provide contemporary information and lessons that could be applied to current issues regarding health and disease.
Sawchuk’s recent study was stimulated primarily by the work of Berkeley demographers Andrew Noymer and Michel Garenne, who argued in a 2000 study that when an epidemic strikes, a particular group -- which usually includes both young and old -- is most vulnerable to it. When the 1918 flu epidemic struck, not only did it lead to a high mortality rate of individuals, but it also disproportionately affected individuals with tuberculosis, rendering those TB victims the most vulnerable to influenza.
“What the authors proposed was that the dramatic decline of tuberculosis after 1918 was largely due to the fact that influenza had selected out these individuals,” Sawchuk said. “During World War I, influenza was considered a silent plague and a new variant in a ‘virgin-soil’ population, and so no one had immunity.” Yet, the search for natural selection has always been present in populations, resulting in evolutionary impact over the years, according to Sawchuk. His paper does not support the findings of Noymer and Garenne, arguing instead that the influenza epidemic did not have a long-term impact on tuberculosis mortality in Gibraltar, and his research refutes other conclusions by the Berkeley team. (To read the paper, click on the link at the bottom of this article.)
The professor’s interest in epidemics dates back to his time as a graduate student. He became interested in studying Gibraltar’s 1804 outbreak of yellow fever, which was transmitted by mosquitoes. Considered one of the deadliest diseases, yellow fever almost wiped out entire populations in Spain and Portugal. Sawchuk said he was intrigued by the fact that people infected by yellow fever who survived were also granted lifelong immunity to the disease, unlike the influenza virus.
Since 1974, Sawchuk has been travelling to Gibraltar, a place he calls his “intellectual home and living laboratory. The country has everything that a good researcher wants to have in a particular population, and I know the culture and history extremely well,” he said. “My whole life has revolved around Gibraltar and research.”
As an anthropology professor at U of T Scarborough for more than three decades, Sawchuk has accumulated a large amount of data. He claims to have birth, marriage and death records of every person who has lived in Gibraltar over the past century.
“It’s only when you immerse yourself in a population for a very long period of time that the Gibraltarians themselves take you under their wing and then you actually begin to appreciate the culture,” he said.
The University of Toronto Scarborough is also the only campus in Canada to have a Centre for Gibraltar Studies, he said. The centre is under the direction of Sawchuk and Professor Clive Finlayson, an adjunct professor of anthropology at UTSC who is the director of the Heritage Division & Gibraltar Museum. Students are able to complete graduate studies focused on Gibraltar and to visit the Iberian Peninsula for research purposes.
“The Scarborough campus is a good home and I love working with my students,” Sawchuk said. “I’ve been fortunate every year to have exceptional students who work in the lab and become very much involved in the research I do.”
To read Professor Sawchuk’s recent paper, click here.