image by: Hans Splinter

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Fast and lethal, the Black Death spread more than a mile per day

Historians and scientists have puzzled about how the Black Death took such a firm hold over such a vast area in such a short time. Some have suggested that the main plague variant was pneumonic rather than bubonic because airborne transmission seems to support its rapid spread. However, pneumonic plague kills so quickly—in a few hours—that it actually spreads slowly because the host rarely lives long enough to infect many people. Most evidence points to the Black Death being the main bubonic strain of plague, spread far and wide by flea-ridden rats on boats and fleas on the bodies and clothes of travelers. In an age of growing maritime trade, food and goods were carried ever longer distances…

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 How Yersinia pestis evolved its ability to kill millions via pneumonic plague

The mere mention of the plague brings to mind the devastating “Black Death” pandemic that spread across Europe in the 1300s. Mass graves were piled high with the corpses of its millions of victims, while the disease rampaged across Europe for many decades. Yersinia pestis, the bacterium responsible for that plague pandemic, still persists in the environment among rodent and flea populations today, and human outbreaks regularly occur around the world.

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Explainer: understanding plague in the 21st century

Pneumonic plague: This can come about after bubonic or septicaemic plague is not treated, but it can also develop when someone inhales infectious droplets from a patient with pneumonic plague. People who have pneumonic plague have a fever, headache, weakness and a rapidly-developing pneumonia. They experience shortness of breath, chest pain, coughing and sometimes bloody or watery sputum.

Plague Transmission from Corpses and Carcasses

In summary, we provide evidence for plague transmission from human corpses. Inhalation of respiratory droplets produced by intense manipulation of the corpse or carcass could result in pneumonic plague, especially after close and prolonged exposure. Direct skin contact with infected body fluids (mainly blood; it is unclear whether other body fluids might also be infectious) could cause bubonic plague, or when a person has cuts on their hands, eventually septicemic plague. These findings suggest that persons handling the corpses of those who have died of plague should use PPE, including an adequate mask, gloves, and gown.

Pneumonic plague

Pneumonic plague is a highly contagious bacterial infectious disease. It can be spread between humans via tiny droplets in the air or may develop as a complication of bubonic plague. The plague still occurs in certain areas of Africa, Asia and America.

Pneumonic Plague Is Deadliest, and Most Rare Form

The pneumonic form is easily spread from person to person through respiratory droplets, much like coughing spreads the microbes that cause influenza, tuberculosis and whooping cough. That is why a cardinal medical principle is to isolate individuals with pneumonic plague and to take all precautions to prevent airborne spread to others.

Pneumonic Plague: Incidence, Transmissibility and Future Risks

Pneumonic plague outbreaks are relatively infrequent in modern times, but in the early part of the 20th century, they were commonplace including several well-documented epidemics responsible for the deaths of thousands. The transmissibility of this disease seems to be discontinuous since in some outbreaks few transmissions occur, while in others, the progression of the epidemic is explosive.

Pneumonic Plague: The Darker Side of Yersinia pestis

The evolution of Yersinia pestis from Yersinia pseudotuberculosis resulted in a dramatic shift from a relatively mild enteric pathogen to one able to cause a rapidly progressing and ultimately lethal pneumonia.

Two Cases of Pneumonic Plague in China Spark Fears of an Outbreak

The timeline of the diagnosis is significant for multiple reasons in assessing the pandemic risk of the highly infectious illness, which can be transmitted by humans. First, although the pneumonic plague is universally fatal when left untreated, if diagnosed and treated with antibiotics within 24 hours of showing symptoms the recovery rate is high, according to the World Health Organization.