Could the ‘Black Death’ Become a Re-Emerging Infectious Disease?

Abstract

During the optimal time of the ‘Black Death’, in the fourteenth century, around 75 million people globally perished, mainly through lymphadenitis. This manifestation of the plague continued to be a disease of major importance until the seventeenth century and the main regions affected were Europe (where 30–60% of the European population was wiped out) and Asia [2]. The ‘Black Death’ is conventionally known within the medical field as the Bubonic plague (named after the buboes commonly found in the armpits, upper femoral, groin and neck region). Together with the septicemic plague and the pneumonic plague, these infections are caused by the bacterium Yersinia pestis (formerly described as Pasteurella pestis). The bacterium seemingly evolved several thousand years ago from a far more benign, gut dwelling bug called Y. pseudotuberculosi (one of a group of relatively benign intestinal diseases). Y. pestis is a facultative anaerobic Gramnegative rod-shaped bacterium. It is unknown if Y. pestis caused all causes of plague during this period, although it stands as the main the etiologic agent (many of the skeletons exhumed from ‘plague pits’) have been tested using a rapid diagnostic test for the detection of Y. pestis F1 antigen to confirm the cause of their death. The bacterium is what is known as a zoonotic disease, indicating its ability to be transferred between different species. In terms of animal to human transmission, the role of rats and fleas (like Pulex irritans) and their detailed role in the transmission of plague has been discovered and experimentally verified [3]. The disease affects the lungs and is highly contagious, leading to mass outbreaks across populations. Without treatment, the bubonic plague kills about two thirds of infected humans within four days [4]. Those infected with the bacteria develop symptoms that can include swollen, tender lymph glands, fever, headache, chills, and weakness. Other symptoms may include muscle pain and seizures. The human body is generally unsuccessful in fighting the disease because cells of Y. pestis can resist phagocytosis. Other major plague events have occurred around the world over the past centuries and similar discoveries of the remains of some of the victims have been made. In 2012 an archaeological discovery of the last remnants of a “lazaretto” or “lazaret” was made in the city of Marseille. This was a place equipped with an infirmary and destined to isolate ship passengers quarantined for health reasons. It was a major site of a plague outbreak.