Amidst the global pandemic and coronavirus outbreak these last few years, something not discussed often in the media is the continued presence of the black plague. Many people think the bubonic plague is a thing of the distant past, but that is not true, and there are reported cases every year. If you did not know it was still around, do not worry because it is unlikely to be the cause of any future pandemics due to advances in medical technology and our understanding of disease transmission. 

The bubonic plague, also known as the black death, originated in central Asia, where climate change forced many rodents out of grasslands into more populated areas. These rodents carried fleas infected with the Yersinia pestis bacteria responsible for the disease. The disease was spread through flea bites or exposure to an infected person’s open wounds. In the incredibly overcrowded cities across Europe, frequent exposure was widespread and aided the rapid spread of the disease. After being infected with the bubonic plague, a person could expect an 80 percent probability of mortality within eight days. 

The disease killed millions of Europeans during the middle ages of the mid-1300s. This disease spread rapidly through crowded cities of Europe, which were often extraordinarily unclean and full of rodents that quickly transmitted it to people. In the 1300s, very little was known about how diseases were transmitted, and there were few treatment options available to compromised people. This plague is responsible for the most significant death toll compared to any other epidemic throughout human history, killing between 75 to 200 million people worldwide. Those numbers are significant because the world population was around 370 million people and faced constant reductions by other factors like natural disasters, famines, and war. The people of Europe did not recover to their former status until almost 200 years later, in the 16th century. 

Symptoms from the bubonic plague caused a person to grow tumors around lymphatic systems in the neck, groin, and armpit. The tumors continued to spread, resulting in large blackening spots across a person’s body accompanied by fevers, vomiting blood, and ultimately death. Less common forms of the plague also appeared in pneumonic and septicaemic variations, killing their host even quicker with 90 to 100 percent mortality rates. Pneumonic plague symptoms infected the lungs leading to respiratory problems, fever, and cough. Septicaemic plague symptoms had a mortality rate close to 100 percent, progressing so rapidly the infected person may not have enough time even to develop the characteristic lymphatic tumors before death. 

Most people consider the black death to be an eradicated disease, but did you know it is still active, with hundreds of cases per year and isolated flare-ups around the world. The disease is still carried by prairie dogs, chipmunks, moles, squirrels, rabbits, and mice. Most modern cases of the bubonic plague occur in central Asia and Africa, but yearly cases are also reported from states across the southwestern United States. Arizona, New Mexico, and Colorado have the highest reported cases in the US, with most deaths only occurring after complications from the disease or lack of treatment. 

The black death is best treated with antibiotics after 24 hours of exposure, but infected people can still make a complete recovery as long as they receive treatment. Fatalities usually only occur when the disease is left untreated. It can run its course carrying a 30 to 90 percent fatality rate compared to less than 10 percent with treatment. 

Understanding past pandemics and epidemics are vital for preparing for and treating future events. If the coronavirus mortality rates were similar to the bubonic plague, the world’s population would have been irreversibly damaged. For comparison, covid19’s case fatality rate is approximately 1.2 percent for the 497 million people that have contracted the disease, an almost minuscule statistic among the global population now totaling more than 7.9 billion people.