Autoimmune Diseases Linked to the Black Plague

The Black Death was an unimaginable pandemic that swept through Europe in the mid-1300s, resulting in catastrophic and severe mortality of the global population at the time. The seven-year plague was responsible for up to 200 million deaths, a significantly more significant impact than the current coronavirus pandemic responsible for around less than 6.6 million deaths. Researchers studying gene mutations and modern human DNA recently discovered links between historic Black Death survivors and autoimmune diseases currently affecting millions of people.  

The significance of the Black Death’s impact at the time also coincides with a much smaller global population of around 392 million people, explaining why the plague had such an enormous impact and required centuries for the world to recover from the devastation. The plague was responsible for removing 30 to 60 percent of the European population at the time, meaning many modern humans of European descent originated from the remaining survivors. 

The enormity of the plague’s impact shaped humanity’s evolution, forcing the selection of survivable traits, which the researchers could observe in skeletal remains and descendants of the survivors. DNA analyses from the skeletons of plague survivors discovered genetic mutations that may have been the reason for greater individual survivability. The DNA study published in Nature found a series of mutations around the ERAP2 gene, equating to a 40 percent greater chance of surviving the plague for sampled individuals. 

The ERAP2 gene is responsible for generating proteins that divide and disperse invading microbes to immune system defenses, allowing it to recognize and neutralize invaders effectively. Survivors of the plague had mutations creating a high-functioning version of the gene, allowing their immune systems to overcome any infections by the deadly disease better. These plague-resistant mutations are still prevalent in today’s modern society as they were passed down through generations. However, modern-day humans may be inadvertently affected by those same high-functioning qualities of the mutations.

The massive impact the Black Death had on earlier human populations has continued to affect modern-day society, implicating descendants of survivors with damaging health consequences. Scientists discovered the increased protein production from the high-functioning gene can be linked to various autoimmune disorders like the damaging inflammatory bowel disease called Chrons. Increased protein production by the specific genes consequently has a negative implication forcing the body to damage itself in response to minor microbial invasions or even the lack thereof. The correlation of the plague’s evolutionary impact to modern autoimmune diseases is baffling but will potentially lead to discoveries regarding these diseases’ origins and treatment. 

Human DNA studies are incredibly complex as they attempt to understand many factors like mutations, environmental pressure, survivability, and inheritance. Similar consequences caused by the Black Death are improbable in the wake of the ongoing coronavirus pandemic. Future descendants of covid survivors will not likely need to address mutation complications because of the low significant impact on global populations and the disease’s inability to impact humans over a diverse age spectrum. Coronavirus-19 statistically has the most significant impact on older people, with deaths over 65 accounting for more than 75 percent globally.

Did You Know The Black Plague is Still Around?

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.