Ebola Virus Disease

From Origin to Outbreak

Adnan I. Qureshi

• Éditeur: Academic Press
• Année: 2016
• ISBN:
  9780128042427
• Sujet: Scienze biologiche
• Sous-sujet: Microbiologia e biologia molecolare

Ebola Virus Disease: From Origins to Outbreak covers Ebola virus disease in its entirety from its origins through major outbreaks in the past to the present day outbreak. It contains information on the West Saharan response to Ebola as well as highlights from the field in West Africa from Dr. Qureshi and Dr. Chughtai, helping to solve the primary question of what's next and aiding in formulating a path forward. With a growing awareness of the devastating effects of this viral disease and an influx of topical research, this book provides the information the global community of researchers, clinicians and students need to better inform their research and study of Ebola virus disease.

• Includes perspectives from the 2014-2015 outbreak from the field
• Provides a detailed overview of the origins of Ebola virus through present day discoveries
• Written with an integrative approach, incorporating scientific research with insights from the field

Chapter 1

Ebola Virus

Nature’s Experiment Gone Wrong

Abstract

The chapter summarizes concepts regarding nature's experiment that are not planned by humans but yet humans form an integral component of the experiment. Over 600 years have elapsed since the world has crumbled under the devastation of the bubonic plague. But yet to our disappointment, the world today is still not an impregnable fortress against the mass spread of diseases which is painstakingly evident in the current Ebola virus disease epidemic.

Keywords

Bubonic plague; Epidemic; Humans; Nature's experiment

Chapter Outline

The first global pandemic 2

Mankind vulnerable no more? 3

And then came Ebola virus pandemic 4

References 6

An experiment comprises of dynamic observations made after addition, deletion, or modification of one or more components within the study perimeters. “Nature’s experiment” is a term used to define experiments where humans do not plan addition, deletion, or modification processes or the components of study perimeters. Nature’s experiments range from the evolution of domesticated dogs from wolf ancestors to the extermination of dinosaurs. In medicine, the term has been used to identify observations of human growth made after genetic defects to the study of etiological agents in disease epidemics. While such experiments are usually the basis of creativity and innovation, the uncontrolled nature of dynamic processes leaves us vulnerable to undesirable consequences. Any experiment where undesirable effects exceed the benefit of the observation is essentially an experiment “gone wrong.” Nature’s experiments are no exception to such a rule.

The Ebola virus infection may have started as a disease within nonhuman primates, initially termed as “green monkey fever,” in order to maintain the fine balance between the number of nonhuman primates and resources available. The competition for survival among nonhuman primates is fierce among the rain forests of Africa as the habitat continues to succumb to the ever-increasing human incursion. Within this “experiment,” less-virulent forms of infectious agents are likely to persist because transmission requires diseased primates to survive long enough to contact one another. Most virulent forms of infectious agents may be their own worst enemy by exterminating the very life sources necessary for survival.

But why did the experiment to preserve the African rain forest habitat go so wrong? Why did the Ebola virus start a pandemic in a world already lured to a false sense of security after its victory over smallpox and polio viruses? Why could no one make a vaccine against the virus, centuries after West Africans had developed and practiced smallpox inoculation and well before the colonial rule started using variolation? A West African woman described her childhood experience in 1890s, “they used to scratch your arm until the blood came and then they got the fluid from someone who had the smallpox and rubbed it in”?¹ During the smallpox epidemic of 1954, Director General Sanner of the Public Health for French West Africa stated, “Time is the only means to diminish the ransom being paid by the people” while awaiting for a cure.¹ In contemporary times, the world would also face a rude awakening that it could not stop the growing Ebola virus disease epidemic.

The first global pandemic

Leonardo Giovanni was the only physician within the fleet of ships that sailed out of Kaffa, Crimea into the Caspian Sea, March 1347. The Italians aboard had a lot to celebrate because they were the lucky few who managed to escape the besieged trading post. The Mongols had launched an attack on Italian merchants in Southern Russia in March 1346. The attack culminated in the siege of last trading station in the region, Kaffa (today Feodosia) in Crimea.

The port stayed in Italian hands due to cold winters and mysterious disease decimating the ranks of the Mongol armies. Leonardo had seen numerous funeral proceedings among the besieging armies from the walls of the port town and had attributed these occurrences to the wrath of God and cold weather. But, the winters had been an ideal breeding ground for disease due to close proximity among individuals huddled in close quarters with limited aeration to survive the cold. Leonardo would also be a witness to perhaps the first biological warfare effort with dead corpses infected with disease being catapulted across the walls by the Mongols. His friend Gabriele de’ Mussi summarized the events as “Whereupon the Tartars (Mongols), worn out by this pestilential disease, and falling on all sides as if thunderstruck, and seeing that they were perishing hopelessly, ordered the corpses to be placed upon their engines and thrown into the city of Kaffa. Accordingly were the bodies of the dead hurled over the walls, so that the Christians were not able to hide or protect themselves from this danger, although they carried away as many as possible and threw them into the sea.”²

For now, Leonardo rejoiced with his companions as they approached the port of Constantinople in May 1347. Three of the sailors were sick and one had died during the journey and Leonardo had been responsible for the care of these sailors. After transferring the sick sailors to local infirmaries, Leonardo chose to spend a few days in the city. It had been a long and arduous winter followed by a hectic and rushed journey and Leonardo had numerous reasons to feel exhausted.

By the third day, Leonardo was exhausted and weak beyond reasons and had developed a high fever and chills. He noticed prominent and painful swelling in his groin and axillary regions. He felt utterly unable to walk and his companions took him to the local infirmary. Leonardo recognized the person lying on the next bed as one of the sailors that he had taken care of who now appeared moribund. The sailor’s fingers were black-colored and the skin had started to erode from nails onward. Leonardo saw himself as a mirror image of his patient.

By evening, Leonardo slipped in and out of consciousness. He was able to piece together that he had acquired the disease by direct contact with sick sailors. There were others out there who had helped him care for his crew members and they needed to be warned of the impending risk. But Leonardo did not live to warn his companions. He was found dead in the infirmary by the next morning.

Leonardo did not witness the horrifying events that were to follow as the disease spread through his companions and their contacts into Constantinople. By July, ships arriving in Alexandria from Constantinople had spread the disease into North Africa and the Middle East. By the second week of September, ships arriving at the port of Marseilles from Constantinople carrying Leonardo’s peers sealed the fate of Europe. The Black Death also known as bubonic plague had come to ravage Europe like no natural calamity or wars to follow. The initial descriptions refer to this plague as the “great pestilence.” In a poem composed around 1350, Simon de Covinus described the great pestilence as the mors atra (literally black or terrible death).³ In the coming centuries, the term “Black Death” will be coined either because of translation of the term mors atra or from the identification of blue–black spots that developed on the skin of infected persons.^3,4 Cities like Pistoia in Italy tried to implement rules and regulations on city inhabitants, closely resembling present principles of quarantine. Travel to any plague-infected area and return was forbidden. No linen or woolen goods were imported into the city and no corpses were buried in the city. However, the city succumbed to Black Death despite strict enforcement of such rules. Today, historians wonder why the disease spread so quickly, a phenomenon that cannot be explained by direct contact or travel routes. The disease overcame natural and man-made fortifications with considerable ease. By the time, plague died down, 25 million people, 60% of all European population, had perished with it.^5–7

What caused the plague would continue to mystify researchers and philosophers alike in the centuries to come. The disease was caused by the bacteria Yersinia pestis transmitted by fleas.⁸ The bacteria would be discovered by Alexandre Yersin in Hong Kong in 1894. A member of the French Colonial Health Service investigating the outbreak, he isolated from buboes the bacteria that was later named Yersinia pestis after him.

Mankind vulnerable no more?

The next 600 years would see the development and availability of advanced hospital care, highly trained personnel, antimicrobial agents, infection-control strategies, and global coordination efforts turn the world into an impregnable fortress against mass spread of diseases called epidemics. The global eradication of smallpox symbolized the ultimate victory of mankind over disease. The World Health Organization, Resolution WHA33.3 on May 8, 1980, declared, “the world and its peoples have won freedom from smallpox, which was a most devastating disease sweeping in an epidemic form through many countries since the earliest time, leaving death, blindness and disfigurement in its wake and which only a decade ago was rampant in Africa, Asia, and South America.”^9–11

But skeptics wondered whether scientific advancements were enough to keep up with a world that now comprised of population-dense cities cloaked with pollution and a world that has overcome barriers to rapid travel across continents, the ideal breeding ground for disease with no boundaries.

And then came Ebola virus pandemic

It was a quiet Monday morning on March 17, 2014, with the darkness of the night withering into the dusk of dawn. Mahmood was finishing his shift as part of his requirements for completion of his medical school studies. The attending physician asked Mahmood if he could evaluate a patient that had just arrived and was waiting in the emergency room. Mahmood walked into the emergency room like he had done numerous times during his rotations. He found a young woman presenting with fever, agitation, conjunctival hyperemia, dyspnea, and blood clot obstructing the nasal cavity. The examination was based on standard practice and did not require any precautionary measures during direct contact with the patient.

Mahmood reported the findings of his examination to the attending physician and made arrangements for hospital admission. The patient’s condition had deteriorated by the time an attending physician made his evaluation. Due to worsening dyspnea, the attending physician placed an oxygen mask and chest electrodes for monitoring electrocardiographic recordings. At 11 am, on March 18, 2014, the patient was dead.

It was the fourth day since Mahmood had evaluated the woman in the emergency room. Mahmood was feeling sick with fever, headache, nausea, and generalized weakness. Mahmood first noticed the fever and fatigue, which was not usual for him gi...