11:23
So, a case of plague has just been reported in Russia, leading to the quarantine of hospitals and the isolation of hundreds of people, sparking global concern about a potential outbreak or, worse, the use of the disease as a biological weapon. So, has the plague returned? And wait a minute, what is a plague anyway? Today we're just going to break it down so you understand what it is, what's going on, and can explain it to your friends. You may have heard of the Black Death, one of the largest plague outbreaks in history, which claimed an estimated 50 million lives in Europe in the 14th century. The disease is caused by a small bacterium called Yersinia pestis.
This bacteria enters fleas, usually when they bite an infected, but very resistant rodent. Bacteria multiply inside fleas so intensely that they form a crust and block their stomach. If such a flea then bites a person, despite the fact that it cannot satisfy its hunger, it regurgitates blood with bacteria into the bite wound. The flea eventually starves to death, but the bacteria begin to infect the new human host, injecting toxins into immune cells, suppressing inflammation and provoking cell death. And all this leads to one of three types of plague. The first and most common is bubonic plague, which affects the lymph nodes. Here they cause severe bleeding, tissue necrosis, and massive swelling, forming painful blue-black ulcers called buboes.
Septicemic plague occurs when bacteria infect the bloodstream and cause tiny blood clots to form, blocking blood flow to the extremities, depriving them of oxygen and causing tissue necrosis. And finally, pneumonic plague, which develops when bacteria infect the lungs. This version is usually transmitted through inhalation of infected droplets from other sick people, rather than through flea bites, which causes the lungs to fill with blood and fluid. Without treatment, the risk of death from any plague is about 70%, but the risk with pneumonic plague is almost 100%. What is worrying now is that the woman who died in Russia had pneumonic plague. It is often considered the most dangerous version, not only because it can kill you
very quickly, but also because it affects the lungs. Therefore, it is more easily transmitted from person to person. Although it can spread through airborne droplets, it does not travel long distances and requires close face-to-face contact for infection. Unlike the flu, COVID, or measles, which are significantly more contagious or more easily transmitted than pneumonic plague. And people who get pneumonic plague get so sick so quickly that they are less likely to spread it to other people and die within a few days. We also have a cure for it. Unlike SARS-CoV-2, which was a novel coronavirus, meaning it was new. We didn't understand its biology. We didn't understand its epidemiology. We had no medicine for it. Unlike the plague, which we have
known about for decades and studied for over a century. There are antibiotics such as gentamicin, doxycycline, and ciprofloxacin that help. In 2025, a man in northern Arizona contracted the plague through contact with sick cats. When the doctors realized this, they were forced to give ciprofloxacin to his family members, colleagues, and hospital staff. And thanks to antibiotics, none of them got sick. But should we worry that it will get out of control and cause another "Black Death" or pandemic? This is unlikely. The truth is that the conditions at that time were much more favorable for the spread of a disease like plague.
Much more crowded conditions with not only people but also rodents and animals that contributed to the spread of the disease, much worse sanitation, less understanding of the disease, and less access to medicine or treatment. Today, plague is rare, with 1,000 to 2,000 cases annually, mostly in Madagascar and the Congo, but the bacterium Yersinia pestis is widespread among animals in the western United States, China, Mongolia, and Russia. And while this case has attracted a lot of media attention, it is still too early to talk about any serious global threat. Which brings us to the question of biological weapons.
There is much historical evidence from China to Europe of the use of infected animal or human carcasses to contaminate enemy water sources. Some sources even suggest that plague victims were thrown into besieged cities with catapults. Even during World War II, it was weaponized by the Japanese army, and the US and Soviet Union considered creating antibiotic-resistant strains that they could stockpile. Although there is little verified information about these projects. Honestly, it's too early to draw any final conclusions. We assume that this was only an isolated incident, and precautions are currently being taken to effectively minimize the spread of this disease.
Plague is a fascinating disease that has played a role in human history, but your attention is better focused on diseases like Ebola or measles, which are actively spreading and much more contagious. In fact, we are currently witnessing the second largest Ebola outbreak in history. The largest in Congo with about 4,000 deaths since May of this year. And measles affects millions every year, with five deaths in Pennsylvania alone in 2026 So yes, the plague is here, but it hasn't gone away. And since it naturally lives in wild rodents, we'll likely see it again and again. But thanks to modern medicine, we will most likely be able to keep it under control.
Thank you very much for watching. Like and subscribe, and we'll see you soon for new science topics. See you later.
