Pneumonic plague, or lung-based plague, is the most virulent form of plague. Incubation can be as short as 24 hours. Any person with pneumonic plague may transmit the disease via droplets to other humans. Untreated pneumonic plague, if not diagnosed and treated early, can be fatal.
In untreated victims, the rates rise to about 50 percent for bubonic and 100 percent for septicemic. The mortality rate for untreated pneumonic plague is 100 percent; death occurs within 24 hours.
Bubonic plague is an infection spread mostly to humans by infected fleas that travel on rodents. Called the Black Death, it killed millions of Europeans during the Middle Ages.
In virtually every textbook the Bubonic Plague, which is spread by flea-ridden rats, is named as the culprit behind the chaos. But mounting evidence suggests that an Ebola-like virus was the actual cause of the Black Death and the sporadic outbreaks that occurred in the following 300 years.
Without prompt treatment, the disease can cause serious illness or death. Presently, human plague infections continue to occur in rural areas in the western United States, but significantly more cases occur in parts of Africa and Asia.
1. Bubonic Plague. Bubonic Plague is a potentially fatal infectious disease caused by the bacterium, Yersinia pestis. Throughout centuries, the disease has erupted several times in different eras, claiming between ten and millions of lives worldwide.
Without the Black Plague, feudalism would persist and the class division in Europe would never end, similar to other parts of the world that stunted their development. One of the most significant features of an overpopulated feudalist society is that labour is cheap and hence easily accessible.
The eventual weakening of the pandemic was likely due to the practice of quarantining infected people that originated in Venice in the 15th century and is with us to this day. Improved sanitation, personal hygiene, and medical practices also played a role in ultimately slowing the plague's terror march.
No. Bubonic plague killed at least one-third of the population of Europe between 1346 and 1353. But that was before we knew it was caused by the bacterium Yersina pestis. Bubonic plague does still occasionally occur in small flare-ups of a few dozen cases, but we have antibiotics to treat it now.
At times of plague, people were asked to mark the doors of the victims of the disease with a large, painted cross to raise awareness. These were initially painted on in either red or black paint, before later on being affixed to the doors.
The first wave, called the Black Death in Europe, was from 1347 to 1351. The second wave in the 1500s saw the emergence of a new virulent strain of the disease.
One mutation, which occurred in a gene called ERAP2, gave people a 40% advantage of survival against the plague. That's the biggest evolutionary advantage ever recorded in humans, Enard says.
In the middle of the 14th century, the Black Death wiped out half of Europe's population. However, Poland and Milan managed to escape the worst of the pandemic and had death rates much lower than those of the other affected nations.
Antibiotics and supportive therapy are effective against plague if patients are diagnosed in time. Pneumonic plague can be fatal within 18 to 24 hours of disease onset if left untreated, but common antibiotics for enterobacteria (gram negative rods) can effectively cure the disease if they are delivered early.
Leading causes of death globally
The world's biggest killer is ischaemic heart disease, responsible for 16% of the world's total deaths.
Smallpox. In 1980, the World Health Assembly declared the world free of smallpox. But before that, humans had battled smallpox for thousands of years, and the more severe version of the disease, Variola major, killed about 30% of those it infected, according to the WHO.
Cardiovascular disease is the top cause of death globally. In the map we see death rates from cardiovascular diseases across the world.
In total, 1,371 cases were reported with 535 deaths across Australia. Because of its coordinated and scientific approach to plague eradication, Australia fared better than many other parts of the world.
At face value, these results might suggest that compared to normal medieval mortality, the Black Death disproportionately affected young adults and very old adults.
The caseload of human plague infection, a highly infectious and severe disease, is low in China, with just one in 2021 and no deaths, down from four infections and three deaths in 2020, according to data from the National Health Commission, which does not specify the types of plague for each person.
The same genetics that helped some of our ancestors fight the plague is still likely to be at work in our bodies today, potentially providing some of the population with extra protection against respiratory diseases such as COVID-19, according to research led by scientists at University of Bristol.
The world's first known plague victim was a 5,000-year-old hunter-gatherer in Europe. The skull of the man buried in Riņņukalns, Latvia, around 5,000 years ago. Humanity has been ravaged by the plague – one of the deadliest bacterial infections in history – for thousands of years.
Researchers identified genetic variants that helped the immune system fight the Black Death, a pandemic in the fourteenth century. The quick burst of immune system evolution may have had the side effect of increasing susceptibility to autoimmune diseases.
It is the most fatal pandemic recorded in human history, causing the deaths of 75–200 million people, peaking in Europe from 1347 to 1351.
It was, in fact, a mask with a purpose. It was actually worn by doctors and physicians as a medical uniform, under the supposition it would have protected them from disease when they visited people infected. The theory was that it would isolate the physician and prevent direct contact with the bodies of plague victims.