May 11, 2020 - Parul Saini, Webmedy Team
When people think of the fatal diseases in the world, their minds jump to the fast-acting, deadly ones that grab headlines from time to time. But in reality, many of these types of diseases don't rank in the top 10 reasons for global deaths. Of the 56.4 million people that passed away worldwide in 2015, 68 percent of them died due to illnesses that grew slowly.
Here is the list of the most fatal diseases ever:
During the Peloponnesian War, typhoid fever hit a quarter of the Athenian troops and a quarter of the population. The definite cause of the plague was undiscovered for many years. Researchers from the University of Athens in 2006 January, examined teeth recovered from a mass grave beneath the city and verified the presence of bacteria accountable for typhoid.
The first reported outbreak of bubonic plague began in Egypt and entered Constantinople the next spring, killing 10,000 a day at its top, and perhaps 40% of the city's residents. The plague went on to kill a quarter to half the human people of the known world.
Originating in Asia, the disease entered the Mediterranean and western Europe in 1348 (probably from Italian traders escaping fighting in Crimea), and killed a predicted 20 to 30 million Europeans in six years; a third of the total community, and up to a half in the worst-affected urban areas. It was the opening of a cycle of European plague epidemics that lasted until the 18th century. There were more than 100 plague epidemics in Europe throughout this period. The disease reappeared in England every two to five years from 1361 to 1480. By the 1370s, England's population was decreased by 50%.The Great Plague of London of 1665–66 was the last major outbreak of the epidemic in England and killed about 100,000 people, 20% of London's population.
The flu pandemic affected around a billion people around the world, including isolated Pacific islands and in the Arctic, killing 20 to 100 million. It killed more people in 25 weeks than AIDS did in its initial 25 years. Mass crowd movements and close divisions during World War I made it spread and mutate quicker and the awareness of officers to the flu may have been raised by stress, malnourishment, and biochemical attacks. Advanced transportation systems made it easier for fighters, sailors, and civilian passengers to spread the disease.
Earlier limited to the Indian subcontinent, the cholera pandemic started in Bengal, then reached over India by 1820. 10,000 British and innumerable Indians died while this pandemic. It stretched as far as China, Indonesia (where more than 100,000 people died on the island of Java only). Deaths in the Indian subcontinent between 1817 and 1860 exceeded 15 million.
The first influenza pandemic to be reported happened in 1510. Since the pandemic of 1580, influenza pandemics have happened every 10 to 30 years. The 1918 Spanish flu pandemic being the most dangerous in reported history. This pandemic was liable for the deaths of 50–100 million people. The most recent, the 2009 flu pandemic, caused under a million deaths. Influenza pandemics happen when a new strain of the flu virus is transferred to humans from another animal species. Flu reaches the world in seasonal epidemics. Ten pandemics were registered before the Spanish flu of 1918. Three flu pandemics happened throughout the 20th century and hit tens of millions of people, with each of these pandemics being made by the presence of a new strain of the virus in humans. Often, these new strains occur from the spread of an existing flu virus to humans from other animal species. Some of these are:
Smallpox was a deadly disease caused by the variola virus. The disease killed a predicted 400,000 Europeans per year in the closing years of the 18th century. In the 20th century, it is estimated that smallpox was liable for 300–500 million deaths As lately as the early 1950s, approximately 50 million cases of smallpox happened in the world each year. After successful vaccination operations during the 19th and 20th centuries, the WHO declared the elimination of smallpox in December 1979. To this day, smallpox is the only human infectious disease to have been completely abolished, and one of two dangerous viruses ever to be destroyed, along with rinderpest.
Measles is an endemic disease, indicating it has been continuously present in a community, and many people receive resistance. In communities that have not been exposed to measles, exposure to a new disease can be destructive. Measles killed about 200 million people globally over the last 150 years.
One-quarter of the world's current population has been infected with Mycobacterium tuberculosis, and new cases happen at a rate of one per second. Yearly, eight million people become sick with tuberculosis, and two million die from the disease globally. During the 20th century, tuberculosis killed about 100 million people.
Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable. In 2018, there were an estimated 228 million cases of malaria worldwide. The estimated number of malaria deaths stood at 405 000 in 2018. Children aged under 5 years are the most vulnerable group affected by malaria; in 2018, they accounted for 67% (272 000) of all malaria deaths worldwide. In 2018, 6 countries accounted for more than half of all malaria cases worldwide: Nigeria (25%), the Democratic Republic of the Congo (12%), Uganda (5%), and Cote d'Ivoire, Mozambique and Niger (4% each). Children under 5 years of age are the most vulnerable group affected by malaria; in 2018, they accounted for 67% (272 000) of all malaria deaths worldwide.
Yellow fever has remained a cause of several destructive epidemics. In 1793, one of the greatest yellow fever epidemics in U.S. history killed as many as 5,000 people in Philadelphia - approximately 10% of the population. About half of the residents had left the city, including President George Washington.
An outbreak of Zika virus started in 2015 and fully enhanced throughout the beginning of 2016, with more than 1.5 million cases across a dozen nations in the Americas. The World Health Organization predicted that Zika had the potential to become a critical global pandemic if the explosion was not controlled.
In February 2004, the avian flu virus was discovered in birds in Vietnam, raising fears of the emergence of new variant strains. It is worrying that if the avian flu virus merges with a human influenza virus (in a bird or a human), the new subtype formed could be both very deadly and highly fatal in humans. Such a subtype could begin a global influenza pandemic, similar to the Spanish flu or the lower fatality pandemics such as the Asian Flu and the Hong Kong Flu.
Coronaviruses are a class of viruses that generate illnesses varying from the common cold to more critical illnesses such as severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). A new strain of coronavirus (SARS-CoV-2) makes Coronavirus disease 2019, or COVID-19. COVID-19 was announced a pandemic by the WHO on 11 March 2020.