From the beginning of history to the present day, humans still fight viruses. Some dangerous viruses could eliminate them with vaccines and have permanently disappeared from our lives, which previously killed thousands.
Here is information on the 12 worst deadly viruses known to humans, based on the likelihood of someone dying if they were infected with one of them, the sheer number of people killed because of them, and the difficulty of treatment and the severity of the infection:
1- Marburg virus
Marburg virus was identified in 1967 when a small outbreak occurred among laboratory workers in Germany because of exposure to infected monkeys imported from Uganda. Marburg virus is like the Ebola virus. Both can cause hemorrhagic fever, so infected people develop high fevers and bleeding throughout the body, leading to shock, organ failure, and rapid death.
According to WHO reports, the death rate in the first outbreak was 25%, but it was over 80% in the 1998-2000 outbreak in the Democratic Republic of the Congo and the 2005 outbreak in Angola.
2- Ebola virus
The first known outbreaks of Ebola virus disease in humans occurred simultaneously in the Republic of Sudan and the Democratic Republic of the Congo in 1976. Ebola spreads through contact with blood or other body fluids or tissues from infected people or animals.
There are several strains of the Ebola virus; there is only one strain (Ebola Reston strains) that is not pathogenic, but for the Bundibugyo strain, its mortality rates are as high as 50%, and up to 71% for the Sudan Strain, According to WHO reports. Recently, a recent outbreak of the disease occurred in West African countries in early 2014, and it is the largest and most complex outbreak of the disease, even causing huge numbers of deaths, reaching 11 thousand deaths in the countries of Sierra Leone, Liberia, and Guinea.
3- Rabies Virus
A vaccine available for this virus for pets has made it a rare disease in civilized countries. However, it is still a big problem in many developing countries in Asia and Africa.
A virus with a great ability to destroy brain cells and cause a hazardous disease, but with the presence and availability of antibodies to the rabies virus, it became possible to quickly treat the patient. Still, if treatment is not available, the risk of death reaches 100%.
4- the gained human immunodeficiency virus (HIV)
A modern virus was discovered in 1981 in the city of San Francisco in a group of drug users and homosexuals, and it is considered one of the deadliest viruses as it causes AIDS, a disease that destroys the entire immune system so that the rest of the germs can be removed from the body easily. In the millions in the world, 32 million people have died from it so far since its discovery, and about 37.9 million people live with the disease until the end of 2018.
Using some medicines made patients infected with the virus live for longer periods of time with the virus. However, so far, it still kills a thousand in poor and middle-income countries, especially in Africa.
5- Smallpox Virus
A fatal disease is transmitted through contact and appears in the form of blisters all over the person’s body. It was spread in most countries of the world. In 1980, the World Health Organization officially declared the world free of smallpox. But before that, humans had fought smallpox for thousands of years, as signs of the disease were discovered in a Pharaonic mummy. The disease kills about 1 in 3 of those infected with it, and it can leave survivors with strong and lasting effects, including blindness in most cases.
Historically, European explorers of new continents such as the Americas were the ones who transmitted disease to the indigenous population and were the biggest cause of the extermination of 90%. In the twentieth century alone, about 300 million people worldwide died of the smallpox virus.
Hantavirus lung syndrome (HPS) first received widespread attention in the United States in 1993, when a young man and his fiancée died in a rural area of the United States within days of developing the disease and developing shortness of breath. A few months later, health authorities isolated the Hantavirus from a reindeer (Deer Mouse) living in an infected person’s home. Over 600 people in the United States have now contracted the hantavirus of lung syndrome, which causes 36% of deaths from the disease, according to the Centers for Disease Control and Prevention (CDC) statistics.
Usually, the virus is not transmitted from one person to another. Still, people become infected with the disease from exposure to the droppings of infected mice. Still, several studies in Argentina mentioned its transmission from one person to another. Previously, a different hantavirus caused outbreaks in the early 1950s, during the Korean War, according to 2010 research in Clinical Microbiology Reviews. Over 3,000 soldiers were injured, and about 12% of them died.
7- Influenza virus
According to the World Health Organization, up to 500,000 people die worldwide during the seasonal flu season. But sometimes, when a new flu strain emerges, a pandemic leads to a faster spread of disease and, often, higher death rates.
Sometimes an infection in the form of pandemic influenza is more deadly and global in terms of spread, like the Spanish flu pandemic or the great pandemic in 1918, which affected about 40% of the world’s population. Resulting in the deaths of an estimated over 50 million people. Scientists are terrified of a recurrence of such a pandemic if an additional strain is found similar to humans and spread among them, which will move easily in our time because of the availability of modern rapid transportation between continents.
8- Dengue virus
The dengue virus that causes dengue fever first appeared in the 1950s in the Philippines and Thailand and has since spread throughout the world’s tropical and subtropical regions. Up to 40% of the world’s population now lives in areas where dengue is endemic, and the disease – with the mosquitoes that carry it – is likely to spread further as the world warms.
Dengue fever affects 50 to 100 million people annually, according to WHO statistics. Although the death rate because of dengue is lower than some other viruses, at 2.5%, the virus can cause an Ebola-like disease called dengue hemorrhagic fever. This condition has a mortality rate of 20% if left untreated. Most scientists believe that it is a major threat to humanity and should be combated not to spread.
A dengue vaccine was approved in 2019 by the U.S. Food and Drug Administration for children ages 9 to 16 who live in areas where dengue fever is common and have a confirmed history of contracting the virus, according to the CDC. However, there are still some problems regarding the use of the vaccine, as the recipient may be at risk of contracting severe dengue fever.
Two vaccines are now available to protect children from rotavirus, which is the leading cause of acute diarrheal disease among infants and young children. The virus can spread rapidly through the fecal-oral route (The Fecal-Oral Route).
Although children in the developed world rarely die from rotavirus infection, the disease is fatal in developing countries, where rehydration treatments are not widely available.
The World Health Organization estimates that over 453,000 children under five died worldwide from rotavirus infection in 2008. But countries that introduced the vaccine have reported sharp declines in hospital and rotavirus deaths.
10- SARS-CoV virus
The SARS virus, which causes severe acute respiratory syndrome (SARS), first appeared in 2002 in Guangdong Province, southern China, and it is from the respiratory coronavirus family. It was likely transmitted from bats at first and jumped to the intermediate host’s mammals, which are wild nocturnal cats. (civets) and then transmitted to humans. It caused an outbreak and a pandemic in China and 26 countries in the world, affecting over 8,000 people and killing over 770 over two years.
The disease causes fever, chills, and body aches, and it often progresses into pneumonia, which is a severe condition in which the lungs become inflamed and fill with pus. The mortality rate for SARS is estimated at 9.6%. To date, there is no approved treatment or vaccine. However, no new SARS cases have been reported since the early 2000s, according to the CDC.
11- Coronavirus (Middle East respiratory syndrome, MERS-CoV)
This virus causes respiratory syndrome in the Middle East (MERS-CoV). It first spread in the form of an epidemic in Saudi Arabia in 2012. Another outbreak occurred in South Korea in 2015. The virus belongs to the same group of coronaviruses (Coronaviruses). Such as SARS and the emerging coronavirus COVID-19 (COVED-19).
It likely originated in bats, too. The disease struck camels before it was transmitted to humans, causing fever, coughing, and shortness of breath in the infected.
The coronavirus that causes pneumonia syndrome often progresses to acute pneumonia. The death rate is estimated between 30% and 40%, making it the most common killer disease known to spread from animals to humans. As with the SARS virus and the emerging coronavirus, COVID-19, they do not have approved treatments or vaccines.
12- Novel Coronavirus COVID-19
The emerging coronavirus, COVID-19, belonged to the same large group of known coronaviruses and was first identified in December 2019 in Wuhan’s Chinese city at the fish and animal market. It is possible that the virus originated in bats, such as SARS and MERS, passed through an intermediate animal (such as eating scale ants or snakes) before people were infected with it.
Since its emergence, the virus has infected tens of thousands of people in China and thousands of others worldwide. The outbreak and its rapid spread have triggered a comprehensive quarantine in Wuhan and neighboring cities, and restrictions on travel to and from the affected countries and the world’s countries have switched a global effort to develop diagnostics, treatments, and vaccines to deal with this pandemic quickly.
The virus has spread to all countries of the world in the form of a global pandemic with terrible spread rates that confused health systems in all countries, infected over three million people, and caused nearly a quarter of a million deaths in the article.
The disease caused by the COVID-19 virus has an estimated mortality rate of 2.3%. People who are older or have underlying health conditions (such as diabetes, heart disease, respiratory disease,.) Are most at risk of developing severe disease or severe complications. Common symptoms include fever, dry cough, and shortness of breath. In severe cases, the disease can progress to pneumonia and cause kidney failure, among others. There is no specific treatment for the disease, and there is no vaccine yet.
This virus caused significant loss of life and economic losses that the world had never seen before. A complete halt to travel and travels between countries and stopping the wheel of industrialization and hindering the service sector and other economic and social activities caused the disease, losing millions of their jobs and complete paralysis in all walks of life.
The article is adapted from an article by Annie Harding and Newcolta Lansi with the same title with some scholarly additions.
The 12 deadliest viruses on Earth. By Anne Harding–Contributing Writer, Nicoletta Lanese.