The plague is as deadly today as in the Middle Ages July 27, 2026The first symptoms that Paul Gaylord noticed felt like a common flu. Two days earlier, he had been bitten by his cat, which had appeared ill. At first, he was prescribed antibiotics to treat cat scratch fever — a bacterial infection that can be transmitted from cats to humans through bites and scratches.

But the medication didn't help. Gaylord's condition worsened, he was admitted to intensive care, and eventually slipped into a coma. Doctors determined that he wasn't suffering from a case of the flu or cat scratch fever, but from the plague.

This infectious disease is more commonly associated with the Black Death of the 14th century than with modern-day Oregon, USA, where Gaylord lived. The infection has not lost any of its deadly potency, but its non-specific symptoms and rare occurrence in modern times make it difficult to identify. Gaylord barely survived, and in 2014, he shared his experience with the British newspaper The Guardian.

Three forms of plague: Bubonic, pneumonic, septicemic The plague is caused by the bacterium yersinia pestis, which can spread extremely rapidly after entering the body in several possible ways. Once there, the bacterium can damage organ tissue and cause bleeding. If left untreated, it is nearly 100% lethal.

The most common type of plague caused by yersinia pestis is the bubonic plague, which is mostly spread by fleas, the so-called "vectors" of the disease. They transport the bacteria by first biting a plague-infected rodent and then carrying it to humans. Yersinia pestis spreads through the lymph nodes, causing painful swelling.

If the pathogen reaches the bloodstream, for example, through the bite of an infected mammal, it can lead to septicemic plague. In the case of pneumonic plague, the pathogen enters the lungs through airborne droplets or aerosols from another person or animal infected with pneumonic plague. This is the only type of plague that is likely to be transferable from one human to another.

The plague: a pandemic in the Middle Ages, rarer today According to the Robert Koch Institute (RKI), Germany's government agency for disease control and prevention, some 3,000 cases of plague were reported across the globe between 2010 and 2015, resulting in over 500 deaths. The most affected regions currently include the Democratic Republic of the Congo, Uganda, and — above all — Madagascar, where the last large outbreak occurred in 2017, and several hundred new infection cases are reported each year. The western United States has also seen occasional cases.

In the Late Middle Ages, between 1346 and 1353, the plague claimed between 25 and 50 million lives. The second in three waves of plague pandemic, it wiped out up to half of Europe's population in just a few years. Why is there no plague left in Europe?

In Europe, the last reported cases of flea-born plague were recorded in France and Italy in 1945. Holger Scholz, molecular biologist and head of the Consultant Laboratory for Yersinia Pestis at the RKI's Center for Biological Threats and Special Pathogens, said that this low occurrence is largely down to the fact that rodents infected with the pathogen are no longer coming and going from people's homes, In the Middle Ages, on the other hand, homes sheltered humans and rats side-by-side, providing fleas carrying yersinia pestis ample opportunity to spread the disease.