Thursday, October 26, 2017

"Medieval" Madagascar

"Medieval" Madagascar: Plague and Inequality 

The Current Outbreak of Plague isn't a Throwback, But a Sign of Modern World 

A guest post by Monica H. Green. 
Dr. Green is Professor of History at Arizona State University. 
Follow her on Twitter @monicaMedHist 

I see dead people. That’s my job. I’m a historian.

But in the past five years, I have seen many millions more dead people than I ever thought I would as a historian of medicine. In the past five years, I have had the experience of slowly realizing that the Black Death—the massive outbreak of plague that struck in the middle of the 14th century—likely affected many millions more people than we ever imagined in our wildest nightmares.

In most of the maps we see when we study this period of history, in most of the texts we read, we are usually taught to think of the Black Death as a pandemic that struck only the Mediterranean and Europe. We teach the Black Death through the stories of Boccaccio, telling us of social breakdown from the perspective of elite Florentines who could afford to escape the city, leaving others to their fate. We learn of the Black Death from manorial records in England, which show tenant after tenant having to pay the heriot, a kind of death tax, in order to inherit land from their deceased relatives. We cringe with horror listening to Ibn al-Wardi, writing from Aleppo, recount the terrifying progression of the plague across the Middle East and into North Africa.

But what we haven’t seen or heard, what we haven’t previously perceived, are the many millions of people beyond the Mediterranean who may have also been struck by the disease. Geneticists now talk of a “Big Bang” in plague’s history, a sudden branching out, an explosive expansion of the causative organism of plague, Yersinia pestis, sometime in the late 13th or early 14th century. This expansion of plague created four new branches in plague’s evolutionary tree. One “branch” went westward, reaching the Black Sea and then the Mediterranean. Two branches likely stayed fairly local in central Eurasia, and may have affected wild animal populations more than humans.

Minimum spanning phylogenetic tree of 133 Y. pestis genomes, with major historical events marked. From Y. Cui et al. 2013, fig. 1A, with additions by M. H. Green. Reproduced with permission.
But the fourth branch spread out just as widely as the first. Strains called by scientists 2.MED and 2.ANT can now be found across almost all of Eurasia, from Jilin Province in northeast China to Turkey and even Algeria, from Russia and Mongolia to Tibet and India. Perhaps as much as two-thirds of Eurasia, and maybe even major parts of Africa, were affected by this pandemic, which spawned continuing outbreaks for centuries.

How do we know this? Because strains of plague initially created in the 14th century still exist in the world today. The evolutionary history that I have just given has been made possible by the fact that this organism still persists on four of the five inhabited continents of the world. Plague outbreaks are not a routine experience for most of us today, but that is not because we ever “conquered” the disease. Plague has never been eradicated, and it won’t be. Rather, we have established an uneasy détente with the organism. We know where it lives, we know how it behaves. And we watch it. Closely.

And that’s why those of us who know plague are watching the situation currently unfolding in Madagascar with increasing alarm. The current toll of 1192 cases and 124 deaths already makes this one of the largest outbreaks in years. Equally alarming is the fact that, of the 22 administrative districts in Madagascar, 14—two-thirds—are reporting cases. This is a plague outbreak out of control.

Why is Madagascar suffering from this “medieval” disease? Because it’s part of the modern world. I live in “medieval” Arizona, a state—like most of the American West—where plague has also insinuated its way into the wild rodent population. Plague arrived in Madagascar and the American Pacific coast about the same time, around 1900, and for the same reason: it was being transported all over the world in the holds of steamships coming out of Hong Kong’s harbor. In both Madagascar and America, it spread inland, finding new hosts and taking up permanent residence.

Plague has changed very little in the past 700 years. It hasn’t had to. We control plague nowadays by using insecticides to get rid of the fleas that transmit the disease from host to host and by controlling rodent infestations. But plague never went away. Only our daily awareness of it did.

What is happening in Madagascar shouldn’t be happening. We know how to monitor this terrifying disease and we know how to control it. We know that a standard arsenal of antibiotics can halt an infection, if it is given very quickly after exposure. We also know that, if not controlled, plague has one of the highest mortality rates of any disease in history.

What we have not yet learned is a lesson the microbial world has been trying to teach us since the 14th century: we’re all connected. Madagascar is suffering now not because it is trapped in its medieval past. Madagascar was indeed connected to a larger world in the Middle Ages, but we have no evidence that plague reached it then. Rather, Madagascar is suffering from plague now because of its connections to the modern global economy. The mining, the textile production, even the very vanilla we use everyday has made Madagascar part of this global economy.

I see dead people in the past. And I cannot save them except by recovering their stories. The people of present-day Madagascar, however, are not beyond our reach. Or beyond our responsibility. We are all connected.

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