The Plague is Still the Plague

The Black Death arrived in Europe in the 14th century and devastated the population. It finally left Europe in the 17th century, after which the population and economy rebounded. As the New York Times reminds us:

The agent of the Black Death is assumed to be Yersinia pestis, the microbe that causes bubonic plague today. But the epidemiology was strikingly different from that of modern outbreaks. Modern plague is carried by fleas and spreads no faster than the rats that carry them can travel. The Black Death seems to have spread directly from one person to another.Victims sometimes emitted a deathly stench, which is not true of plague victims today. And the Black Death felled at least 30 percent of those it inflicted, whereas a modern plague in India that struck Bombay in 1904, before the advent of antibiotics, killed only 3 percent of its victims.

The different reactions of populations to the plague in more recent centuries has led researchers over time to assume that the medieval microbe must have been different from the modern one. New DNA analyses, however, suggest that they are in fact the same. Studies into the DNA of the plague are continuing, but if the microbe really is the same, then we are going to have to conclude that people reacted differently somehow in medieval times than now. But since we don't know why this might be true we are once again reminded that we need to protect ourselves from these dangerous microbes in any way possible.