Introduction
Black Death was the worst infectious disease that primarily affected the European people from the year 1348 to 1350. After this period, the disease occurred repeatedly up to the19th century. The Black Death significantly affected the European population following the recorded death of over 50 million people, which formed approximately 30% of the whole population.
Despite numerous evidences showing that a bacterium called Yersinia pestis was the cause of Black Death, several scientists are still unsatisfied because scientific data lacks concrete evidence to support the occurrence and spread of Y. pestis from China to Europe. According to the French Press Agency, genetic studies supported prominent theory by confirming that, Y. pestis caused Black Death because scientists and anthropologists found it in the teeth and bones of plague victims (Para. 1).
Since scientific data has been unclear and controversial, it raised a lot of disagreement. However, genomic investigations have yielded reliable information that incriminates Y. pestis as the cause of Black Death. Therefore, in spite of the controversy surrounding the cause of Black Death, modern genetic studies have confirmed that Y. pestis is the bacterium that was responsible for the Black Death in Europe.
What is Black Death?
Black Death was an infectious disease that occurred in Europe and killed about a third of the population during 14th century. Characteristics of the disease were similar to hemorrhagic fever caused by virulent viruses, such as Ebola and Anthrax, because victims of the disease vomited blood before dying within a short period after infection.
According to Revil, eyewitness accounts described signs and symptoms that, boils first occur on thighs, then spread throughout the body, patients vomited blood and then die within three days since there was no cure (Para. 8). The signs and symptoms of the Black Death show that it spread quickly making it difficult for doctors to investigate.
Based on the massive occurrence of deaths in Europe, many people attributed the cause of Black Death to “bad air” that had infectious agents. Currently, scientists are still grappling with the cause of Black Death because contradicting evidences and theories continue to emerge in the medical sphere.
In 1348, Black Death entered Europe and caused disastrous death of population within a period of one a year. Parry reports that, in London alone, an emergency cemetery received about 200 bodies per day in a consecutive period of three months, plus many other bodies buried in local graveyards (Para. 1).
Occurrence of massive deaths did not only shock families and governments, but also scientific community. They have been continually wondering about the real cause of the Black Death. Since Black Death took a toll on Europeans, authorities in London provided East Smithfield as a remarkable cemetery where they buried bodies of victims stricken by the plaque.
During the 14th century, the Black Death killed over 50 million people and it took about 150 years for Europe to regain its population. From the incidence of the Black Death, people have learned that infectious diseases are quite devastating and can break out any time. Thus, if preventive measures are not in place, people are at a great risk of facing further occurrence of infectious diseases.
Current Debate of Black Death
The reappearance of infectious diseases has forced scientists to work tirelessly to improve their understanding of infectious diseases so that they can create preventive measures. Since the cause of Black Death triggered a significant deal of controversies, contemporary scientists are revisiting issues involving Black Death with the objective of harmonizing different theories and formulating conclusive and valid information, which explains the cause and preventive measures.
Scientists need to understand the causes and preventive measures of infectious diseases so that, in case of any recurrence, they can tackle it appropriately, and thus save many lives. Medical scientists have found out that, Black Death emanated from China and then spread towards Europe.
Thus, infectious diseases have no boundaries because they trespass across countries and cause catastrophic infections that can even wipe humanity off the face of the earth, if appropriate interventions are not put in place. Wade explains that, Black Death did not occur during the 14th century only; it periodically recurred every ten years (“Europe’s Plagues” Para. 2).
Thus, a possible reappearance of infectious diseases has forced scientists to study historical incidences of infectious diseases like the Black Death, so that they can understand the causes and the appropriate prevention measures.
During the 17th century, London suffered another plague, which did illustrate that Black Death is a recurring disease that could occur in the future. Therefore, recurring nature of Black Death have compelled scientists to do more research, at least to come up with plausible theories and information that is critical in prevention of Black Death. Wade argues that, archeologists have been looking for the remains of the plague victims in mass graveyards to obtain genetic materials for further studies (“Hunting Graveyards” Para. 4).
Scientists collected genetic material for genetic analysis as an effective way of determining the real cause of Black Death. Genetic studies conducted by various scientists have proven that microbes’ genetic material in bones and teeth of the victims resemble that of Y. pestis. Robust findings of genetic studies have convinced many proponents of virus theory, thus enhancing settlement of debate that has been raging for centuries.
Theories of Black Death
Scientists have created many theories to explain the cause of Black Death, but they have not come to a definite conclusion. One theory that seems plausible is a bacterial theory, which supports that a bacterium known as Y. pestis caused the Black Death that swept Europe during the 14th century.
The bacterial theory said that Black Death started in China was spread into Mediterranean and European parts because Black Rats, which were in merchant ships carried vector fleas, had Y. pestis. According to French Press Agency, scientific studies of DNA samples were collected from remains of plague victims have proved that Y. pestis is the undisputable cause of Black Death (Para. 2).
Analysis of DNA samples has proven that Y. pestis is a bacterium strain responsible for pandemic occurrence of Black Death in Europe during 14th century. The theory is reliable and valid because it relies on scientific evidences that emanate from genetic studies. Use of DNA samples in ascertaining relationship between Y. pestis and Black Death is effective because DNA material is relatively stable over a long period.
Viral theory is a theory that opposes bacterial theory. The theory claims that infectious viruses were responsible for the occurrence of the Black Death. Supporters of the theory argue that, there are many evidences, which prove that viruses were responsible for the occurrence of the Black Death.
The supporters dispute the findings that Y. pestis did not cause Black Death. Since Black Death spread rapidly across Europe and the world, proponents of viral theory assert that, it is quite impossible to claim that rats, which had fleas, were vectors of the plague because they can only move within a limited range, unlike people. Instead, they argue that the virus was the cause and man was responsible for rapid spread of the plague.
Revil argues that, analysis of hundreds of epidemics illustrates that rats did not disseminate the plague from one town to another, but oriental travelers who moved from one place to another since death records shows deaths of strangers (Para. 2).
Therefore, since rats and fleas cannot move widely, it is possible that human beings caused the rapid spread of the Black Death, which supports the viral theory. Given that viruses can live in human beings, viral theory claims that human beings were responsible for the rapid spread of a virus that caused the Black Death.
Controversy of Black Death
The cause of Black Death has elicited controversy since scientific data provide vague and contentious evidence. Although, Black Death occurred many centuries ago, modern scientists doubt whether Y. pestis is the cause of the plague. It might have resulted from other microbes.
Comparative studies conducted to determine whether the occurrence of Black Death in different parts of the world has some similarities revealed that there are significant differences. According to Wade, Victim bodies of European Plague emitted deadly smell, while recent plagues victims do not do so (“Hunting Graveyard” Para. 3).
Moreover, modern plague like the one that struck Bombay, India in 1904 only killed about 3% of its victims, unlike the European plague that killed a considerable number of populations.
Such comparative studies show that there are different strains of microbes that cause Black Death; hence, it is not enough to assert that Y. pestis is the only agent that causes the plague. Critics of bacterial theory argue that Y. pestis is not the sole cause of Black Death because virulent nature of microbes did vary during the medieval period.
Another point of controversy emerges from the scientific assumption that Black Death arbitrarily killed people across populations in spite of differences in age and health status. However, Bakalar argues that, the assumption was false because according to Proceedings of National Academy of sciences, studies on bones show that Black Death affected people who were ill while healthy people survived (Para. 2).
Examination of the bones shows that many of the European victims had bones with lesions, meaning that they had malnutrition and weak immune system when they died. Thus, given that unhealthy people were vulnerable to Black Death compared to the healthy people, it implies that proper nutrition is central in preventing and alleviating impacts of plagues. However, Ebola and Severe Acute Respiratory syndrome affect people arbitrarily thus making Y. pestis unexceptional.
Even though scientists have not agreed on the cause of Black Death, genetic studies have helped them to reach an agreement that has resolved the controversy surrounding the Black Death. Currently, some scientists do not believe that a bacterium, Y. pestis, caused the Black Death according to claims of the bacterial theory.
According to Wade, due to genetic studies, scientists no longer doubt the cause of Black Death after they detected genes of Y. pestis in the remains of the plague victims found in mass graves in Europe (“Scientists Solve Puzzle” Para. 3). By use the of modern genetic tools and techniques, scientists can now form a complete genome of Y. pestis and study its virulent properties, which have formed the basis of studying modern infectious diseases.
Bos et al. argue that DNA amplification and sequencing has transformed genetic analyses of DNA samples in ancient specimens (Para.1). Genetic amplification and sequencing is central in the study of infectious diseases because ancient genomic data of microbes aid in the elucidation of virulent and mutation properties of infectious pathogens.
My Opinion
Even though the debate concerning the cause of Black Death has raged for many centuries, it has yielded significant conclusion in the health research because it has demonstrated that scientific evidence takes precedence in health issues. Scientists were not able to establish what caused Black Death because it was a strange infectious disease, which had never occurred.
Although it was not clear how rats and fleas spread the plague across Europe within an extraordinarily short period, some evidences suggest that humans were also responsible for the spread. During 14th century, people had no sophisticated scientific methods of diagnosing the cause of diseases; hence, they relied on unreliable diagnostic techniques that produced vague evidence.
However, scientific study of genes has enabled scientists to study genetic material from remains of people who died long time ago. Moreover, scientific study of genetic material has allowed scientists to understand how infectious agents cause diseases.
Discourse of Black Death employs buzzwords such as the black plague, mass killer, DNA amplification and sequencing, genomic investigations, pandemic, endemic, bubonic plague, Black Death genome, hemorrhagic plague, and plague victims amongst others. A conceptual metaphor in the Black Death discourse is “…plague arrived like the fourth horseman of the apocalypse” (Wade, “Scientists Solve Puzzle” Para. 7). Buzzwords and metaphors enhance the understanding of Black Death discourse.
Conclusion
Black Death was a bacterial infection that hit Europe during 14th century killing approximately 30% of Europe’s population. Since there was no cure then, and the plague was extremely virulent, the Black Death caused death within few days after infection. Based on the insufficient scientific evidence to incriminate a pathogen, scientific community divided itself over the cause of Black Death.
This followed since some argued that it was a viral disease, while others argued that it was a bacterial disease. Controversy over the cause of Black Death continued to modern society when scientists have invented genetic techniques of extraction, amplification, and sequencing of organism genome. Thus, genetic studies effectively resolved the debate after concluding that a bacterium known as Y. pestis is the cause of Black Death, and not a virus as asserted by some scientists.
Works Cited
Bakalar, Nicholas. “Clues to Black Plague’s Fury in 650-Year-Old Skeletons. The New York Times 2008. Web.
Bos, Kirsten, et al. “A Draft Genome of Yersinia pestis from Victims of the Black Death.” Nature. 2011. Web.
French Press Agency. “Black Death Blamed on Bacteria.” Discovery. 2010. Web.
Parry, Winnie. “Genetic Clues of What Really Caused Black Death.” Science. 2011. Web.
Revil, Jo. “Black Death Blamed on Man, Not Rats.” The Observer 2004. Web.
Wade, Nicholas. “Europe’s Plagues Came from China, Study Finds.” The New York Times. 2010. Web.
Wade, Nicholas. “Hunting for a Mass Killer in Medieval Graveyards.” The New York Times. 2011. Web.
Wade, Nicholas. “Scientists Solve Puzzle of Black Death’s DNA.” The New York Times. 2011. Web.