The Black Death In 1346 ships arrived at the port of Messina, Sicily, with silk and spices; rats carrying the Y. pestis bacteria; and crews covered in boils that oozed blood and pus. Sicilian authorities soon ordered all these "death ships" out of the harbor, but it was too late--once-healthy people all over Europe were about to die. Because much of the plague was airborne, it easily spread from person to person, which meant coughing or sneezing on someone was potentially enough to kill them. The "death ships" of Messina were not the first instance of plague. Because it originated in the Far East, it had already killed many in countries like China, India, and Egypt, steadily moving west. But commerce must move on as well, and so the ships came, seeking a port in the storm. After Messina, the Black Death reached Marseilles in France and Tunis in North Africa. Then it spread to Rome and Florence, two Italian cities that were the hub of circuitous medieval trade routes. So, why were the humans so unlucky? The answer is: we still don't know. Researchers today agree that Yersinia pestis causes the plague. But how and why the Black Death spread so quickly and was so destructive is still up for debate. But we'll start with  Y. Pestis . It's a rod-shaped bacterium covered with a layer called "biofilm" that is really nothing more than a clinical term for slime; this slime prevents  Y. Pestis  from being eaten by other cells. Rattus A rat may get Y. Pestis from a flea bite; most often it's a black rat that will become infected with the bacteria, and the rat becomes a "reservoir" for Y. Pestis , while the flea is a "vector." ("Vector" is another word for biting insect that spreads disease from one living thing to another.) If you're the type to get the heebie-jeebies from seeing a rat, it probably doesn't matter if it's a black or brown rat. One doesn't take the time to investigate, one just sees "a rat!" But from an epidemiological standpoint, particularly when it comes to the Black Death, the rat does matter. Rats belong to the genus Rattus . (Despite its name, Rattus includes not only rats but hamsters, mice, and gerbils, though we'll concentrate on the rat right now.) The brown rat, or Norwegian rat ( Rattus norvegicus ) is brown but is not Norwegian. It probably originated in China. How it got to be called "Norwegian" is unclear, though it might have been English naturalist John Berkenhout who gave it the misnomer, believing it came from Norwegian ships. The name stuck, and therefore the rat is incorrectly thought to be Norwegian. (See another great misnomer in the chapter on the Spanish Flu.) Brown rats are larger than their cousin, the black rat, and they have larger ears and a longer tail. Wherever people are, brown rats are right there with them, scavenging and making more rats. Brown rats are sometimes mistakenly thought to have spread the Black Death, and indeed they can suffer from the plague, though researchers believe the major reservoir of bubonic plague is the black rat ( Rattus rattus ). This rat originated in southern and southeast Asia, then traveled west through the Middle East all the way through continental Europe and eventually to Great Britain and Ireland. Rats are terrific vectors for many diseases because of their ability to hold so many infectious bacteria in their blood without dying off themselves. What can kill it are cats, owls, weasels, foxes, and coyotes. That doesn't place the black rat at the top of the food chain, but black rats run quickly and are fast climbers, allowing them to survive the array of predators. When an uninfected flea bites an infected rat, it ingests the rat's blood and bacteria, including, Y. Pestis . The slime that covers the bacteria causes a backup between the now-infected flea's esophagus and gut, meaning the flea can get food into its mouth but not into its stomach. The only way the flea avoids starving to death is by vomiting the blood and bacteria into whatever mammal it then bites. If that mammal is human, he or she is in danger of contracting the plague. This is what classifies the disease as zoonotic in that it's able to pass from animals to humans. (As we'll see later, barnyard animals are notorious for making people sick as well.) Rats--who eat everything from pizza to wires--also love grain. And many of these trading ships were stuffed to the gills with grain, just like the rats that stowed away on them. Usually, rats only travel about a mile from where they're born, which is why the plague may have stayed in one place for so long. But these grain ships were possibly the ones that brought the disease west in the first place, since Egypt's rat population exploded by feeding on the large granaries there, but now they were sailing halfway around the world and unknowingly starting a pandemic. Now consider something cuter than Rattus rattus : the gerbil. While it's easy to point a finger at something, well, ratty, gerbils are welcomed as pets, given their own home, and allowed to crawl all over children. If someone were to do this with a rat, they might be written about in horror stories or police blotters. It's the gerbil's cuddly look and docile nature that lure people into believing they're harmless, and while gerbils wouldn't spread plague with intent, the result would be the same. Gerbils, which are relatives of rats, inhabit--among other places--the same parts of Asia that rats do; they also carry fleas and hop on ships bound for parts unknown. Rats have shouldered the blame for the Black Death for several centuries (even more than fleas), but it's only just now that researchers from the University of Oslo are comparing the dates of plague outbreaks with climatic data that are revealed in tree rings. The results show that major temperature fluctuations in Asia--extreme highs followed quickly by extreme lows--preceded plague outbreaks in Europe by about 15 years. That kind of weather, they believe, would have been too wet for rats to flourish and carry infected fleas across continents but just right for rat cousins like gerbils and marmots. Under these conditions, fleas also become more active, and gerbils more numerous. Indeed, researched found that an increase of 1-degree Celsius doubles the prevalence plague in Central Asian rodents. Could it be that these furry little friends are rats in gerbil's clothing? Plague Varieties What we do know for sure is that Y. Pestis  is a type of bacterium that's beyond bad. It's the cause of the plague. And not just one plague but at least three that we know of : bubonic, pneumonic, and septicemic. Bubonic plague is the most common form of the disease. It is marked by the sudden appearance of bulbously swollen, blue, and painful lymph nodes (called buboes) in the groin or armpits, where our lymph nodes are. (In fact, bubon is Greek for "groin" or "swollen groin.") Bubonic plague is not directly transmitted from one human to another unless there is direct contact with lymph node tissue or secretions; it's usually caused by the bite of an infected flea. Back in medieval times, you had about a 15% chance of surviving. Pneumonic plague, the second most common, can start as bubonic plague but then settle into the lungs, causing a rapid and severe form of pneumonia that leads to respiratory failure, shock, and death. It is the only type that can be spread person to person if someone inhales infected water droplets traveling through the air. No one survived pneumonic plague. Septicemic plague, the rarest, can also start as bubonic plague but then attacks a person's blood cells, causing skin or other tissue to die and turn black, especially on the extremities of hands and feet. It's caused by either an infected flea bite or by handling an infected animal. The bad news is you will most definitely die from septicemic plague, but the good news is it won't take long. Perhaps even just one day. No one knew exactly how the Black Death was transmitted, and no one knew how to prevent or treat it. For example, one doctor claimed that "instantaneous death occurs when the aerial spirit escaping from the eyes of the sick man strikes the healthy person standing near and looking at the sick." Father abandoned child, wife husband, one brother another, for this illness seemed to strike through breath and sight. And so they died. And none could be found to bury the dead for money or friendship. Members of a household brought their dead to a ditch as best they could. And in Siena great pits were dug and piled deep with the multitude of dead. And I, Angelo di Tura ... buried my five children with my own hands ... And there were also those who were so sparsely covered with earth that the dogs dragged them forth and devoured many bodies throughout the city. -Angelo di Tura of Siena, Italy Around 1347, a banker named Giovanni Vilanni happened to be chronicling the history of Florence when the plague arrived. His Nuova Cronica is a treasure for the amount of detail he gave that other writers would have overlooked--the number of banks, bakeries, notaries, and surgeons in Florence; the name of every street, square, bridge, and family. While Vilanni's mind focused on the statistics that made up Florence, the plague is what captured his creative side. In the autumn of 1347, Villani predicted, "This plague was ... foretold by the masters in astrology last March.... The sign of Virgo and its master ... Mercury ... signif[y] death." That winter, earthquakes in Italy and Germany underscored Vilanni's belief that the end was nigh, especially after a "column of fire" glowed over Avignon, France. Eyewitnesses claimed it was a natural phenomenon produced by "the sun's rays like a rainbow," but Vilanni maintained its appearance "nevertheless [is] a sign of future and great events." By "great," Vialnni meant "terrible." Of the plague, Vilanni wrote about it as though it were an unwelcome visitor, yet one that couldn't help but admire the beauty of Florence. Stopping to admire "views that resemble paintings," and Florence's "beautiful streets, beautiful hospitals, beautiful palaces and beautiful churches," he observed how the plague burst into homes and churches and upon the inhabitants "with the speed of fire racing through a dry or oily substance." The last line of Nuova Cronica states: "The priest who confessed the sick and those who nursed them so generally caught the infection that the victims were abandoned and deprived confession, sacrament, medicine, and nursing.... And many lands and cities were made desolate. And this plague lasted till _____" Villani left this last part blank so he could fill in the date when it ended. But Villani died of the plague in 1348. His brother Mateo continued the Cronica until he too died from the plague, and it was finally completed by Mateo's son, Filippo Villani, in 1364. That the plague brought Florence to its knees was especially poignant because by the fourteenth century it was arguably the most cosmopolitan, artistic, and influential city on the Italian peninsula. Though one would have thought that title belonged to Rome, the fall of the Roman Empire and, more recently, the pope's move from Rome to Avignon dimmed Rome's glory. Now it was Florence that bloomed, a place where works of art were sponsored by patrons to beautify the city, and its famed banking industry brought economic prosperity. Florence even got a head start on the Renaissance thanks to painters like Giotto, writers like Dante, and sponsors like the Medici banking family. And there was Orsonmichele, a Florentine church with a façade adorned with the bronze and stone statues of the saints carved by the likes of Donatello. But all the beauty, money, and piety couldn't help Italy's wealthiest city. The plague likely entered through Florence's closest port city, Pisa. Once Florentines realized the pestilence had begun, city leaders took precautionary measures like destroying the clothes of the sick and the dead instead of selling them, forcing all prostitutes to leave the city to help cleanse it of sin, and preventing people from Genoa and Pisa from entering. In June 1348, the death rate was about 100 people per day; by August it was 400 per day--at least 20 times what was considered normal. By October the population had been cut from 100,000 to 50,000. The Grain Office, or Grascia , was originally in charge of distributing grain, making sure it got to market, and controlling the price. The Grascia later absorbed a judicial office that kept a record of the weekly dead called the "Book of the Dead" or Libri di Grascia Morti . The first book contained those who died during the Black Death and included the following: the deceased's name, where they lived, cause of death, what parish they were buried in, and the gravedigger who buried them. Depending on who did the recording, there could be a plentiful amount of information or barely a name. The Grascia Morti did not take into account those who fled to the countryside to wait out the plague, including city leaders. The End However, those who stayed and either avoided or recovered from the plague were often richly rewarded. Members of a guild--which was a type of exclusive union--and those in banking made sure their estates were taken care of. More wills were written than ever before, and this sometimes left the power and money consolidated into one family member. The Florentines also had a great spirit of charity, and huge donations were made to help the needy. When the plague finally burned out in 1349, Florence was ready to get on its feet again. It was battered but unbroken, with an optimism that included a drive to repopulate the city on several fronts. One was to offer incentives for artisans and craftsmen to move to Florence; another was to make guild and monastery membership easier to attain. Still another was a push to literally repopulate the city by ensuring that every woman of marriageable age had a dowry--money or goods that she brought into a marriage. Marriages then were more like financial or political transactions. The Florentine Dowry Fund ( Monte delle doti ) was set up to make sure women brought enough to the table to get married and therefore have babies. So, what happens when a plague ends? The answer is that life goes on. What else is there to do? There are still mouths to feed, land to till, markets to tend. But there was a surprising benefit to the enormous casualties the Black Death left in its wake--an economic boom. Whereas before the plague there had been famine, low wages, and a surplus of workers, after the plague the few remaining shoemakers, blacksmiths, and the like could demand higher wages and pay lower rent for the land they worked. Fewer people also meant less demand for food, so farming itself became less profitable. A mass migration into towns and villages began with men taking jobs in cloth- or brick-making. Others became traders or servants. Family farms were abandoned. Landowners changed their business plans, too--they embraced a new way of life called capitalism, which continues today. Excerpted from Plagues, Pandemics and Viruses: From the Plague of Athens to Covid 19 by Heather E. Quinlan All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.