The depletion of the human population

Human history has witnessed various diseases that turned out as an epidemic and affected a large number of people that resulted in the depletion of the human population. Epidemics have killed more people in history than any other thing and various successful efforts have been made to prevent such diseases. But first, let us comprehend what an epidemic really is and what is the major difference between an epidemic and a pandemic. An epidemic is an infectious disease that spreads in a large number of people within a community or area during a short frame of time.

It is the rapid and unexpected increase in the number of cases of a disease. Epidemics usually arise when microbes find a vulnerable group of people that can be easily infected and an agent to pass from one person to another. Epidemics can be classified as common source and host-to-host. Common source epidemics result from a contaminated source like air or water whereas host-to-host epidemic occurs when an infection passes from one individual to another. Pandemic, on the other hand, refers to an outbreak of an epidemic that spreads over a wide geographical area or several countries and continents, affecting a large number of people.

For instance, SARS first affected people of China but later turned out as a pandemic that spread to 37 countries. Epidemics in the Past In past, various diseases proved fatal and turned out as epidemics that claimed the lives of people at various places. The epidemics of plague, leprosy, smallpox, cholera, whooping cough were the most common in the past. Bubonic Plague, also known as The Black Death is one of the first “true pandemic on earth” that literally depleted population in half and claimed the lives of people in Asia and Europe.

It originated in Asia around 1330 and spread to Europe, Middle East, and North Africa through land and sea. This epidemic affected the population, agriculture, family structure, and economics. Another diseased that turned out to be an epidemic was Smallpox. It came to North America in 1600 and was brought by the Europeans and claimed the lives of “nearly 90 million Native Americans” and wiped out the entire tribes. Cholera is also a disease that caused an epidemic in the 19th Century. It was a disease common in India that later spread in the world.

The United States had witnessed “three serious waves” of this disease between 1832 and 1866. Epidemics of Today The progress in medicine has greatly helped in the reduction of epidemics. Different vaccinations and antibiotics helped in the prevention of such diseases that cause epidemics as stated by Sir McFarland Burnett that by the Second World War the problem of dealing with an infectious disease would be solved. But the environmental change and overpopulation have again resulted in the emergence of epidemics. Some scientists say that population rise would bring “new challenges in controlling disease outbreaks”.

Moreover, the fast communication and transportation have also resulted in the rapid spread of epidemics throughout the world. Some of the diseases that turned out to be an epidemic in the 21st century include HIV and Aids, Ebola, SARS, and H1N1. SARS stands for severe acute respiratory syndrome. This is the best instance when an epidemic moved rapidly to the other countries. It first infected people in China but later spread across two continents in just a week through one infected passenger who passed on this disease to the fellow 22 airline passengers.

This disease infected “8,000 people” around the world of whom 800 had died. HIV and Aids is considered as the modern epidemic that first emerged in 1980 and is still on the rise. This disease has so far affected “60 million people” and has caused “an estimated 30 million deaths”. People all over the world become infected with this disease and about “34. 2 million people” are living with HIV around the world. About “50,000 people” become infected with this disease each year in the United States and the numbers are still rising.

Ebola virus disease also turned out to be an epidemic in West Africa in 2014 and rapidly became the deadliest. This virus has claimed 11,315 lives and has caused a huge socioeconomic disruption in the region. Similarly, another disease that can turn out to be an epidemic today is Zika virus. It is caused by the bite of an infected mosquito but what more alarming is that it can transfer from a pregnant woman to her fetus causing birth defects and neurological problems. This disease has so far affected Brazil, and some parts of South and North America.

Sources:
• Gottfried – The Black Death (1985)
• BENFIELD, E. & TREAT, J: As Ebola death toll rises, remembering history’s worst epidemics. National Geographic, October 25 2014.
• HOWARD, C.R & FLETCHER, N.F.: Emerging virus diseases: can we ever expect the unexpected? Emerging Microbes & Infections (2012)

Internet sources:
https://www.cdc.gov/ophss/csels/dsepd/ss1978/lesson1/section11.html
https://www.livescience.com/41478-scariest-disease-outbreaks.html
https://www.healthline.com/health/worst-disease-outbreaks-history#overview1

The 10 deadliest epidemics in history

http://www.bbc.com/news/world-africa-28755033