Top 10 Deadliest Viruses in the World

Several millions of virus species have been identified till the present time i.e. 2018. However, a mere total of about 5,000 of them are described in detail by scientists and researchers across the globe. Ever since Dmitri Ivanovsky’s published article unfolded a non-bacterial pathogen infecting tobacco plants in 1892, and the subsequent discovery of tobacco mosaic virus 6 years later by Martinus Beijerinck, scientists and researchers have been keenly studying viruses in detail. Understanding the way in which in viruses thrive, helps in developing better cures. While some of them might not be dangerous at all, other are potentially lethal. So, here we are with our pick of the Top 10 deadliest viruses in the world.


10. Dengue Fever Virus


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Found in China, the very first description of dengue fever virus dates back to about 2,000 years. The dengue fever is a mosquito-borne infection. The disease became widespread during the 18th century. This was due to the spreading of populaces of Aedes Aegypti mosquitoes to different countries in the world.

The most important symptom of the virus includes severe pain in joints and muscles. Thus the name, breakbone fever. In the present scenario, the virus has affected 110 countries with an average of 500 million infections and 20,000 deaths in a single year. Dengue Fever Virus, is thus, number 10 on the list of top 10 deadliest viruses in the world.



9. Lassa Virus


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Lassa virus kills as many people in the West Africa on a yearly basis as the Ebola massacre did during the unfortunate 2013-2015 epidemic. Lassa virus is classified in league with Ebola as acute viral hemorrhagic fevers. As such, its symptoms can be easily confused with Ebola virus.

The virus is spread by Mastomys rats. Lassa virus infects almost every tissue in the human body. For those working on the virus, biosafety level 4 (BSL-4) is adhered to. Breakouts of the virus infect about 300,000 people each year with a yearly death toll reaching about 5,000.


8. Hepatitis


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Number 8 on the list of top 10 deadliest viruses in the world is Hepatitis. As a matter of fact, Hepatitis is an umbrella term for a number of viral diseases that targets the largest organ in the human body i.e. liver. There are 5 forms of hepatitis, each distinguished from others with an additional alphabet, from A to E, added to hepatitis. Among the group, Hepatitis B and Hepatitis C are the most lethal versions of the liver-affecting disease. Collectively, these 2 contribute to almost 1 million deaths all over the world.

Even though the most primary form of contracting the disease is via mother to child, it can also spread via blood transfusions, dirty syringes, unsafe sexual activity, and tattooing. Out of the somewhat a million deaths each year, Hepatitis B contributes to about 70% of all those demises. Moreover, it has no distinct symptoms making it extremely difficult to identify.


7. Hantavirus


The latest outbreak of the Hantavirus in the US hit the Yosemite National Park, back in 2012. Carried by rodents, there are several strains of the deadly virus. Moreover, different rodent species carry different strains that lead to distinct types of illness. 2 of the most lethal conditions caused by Hantavirus are HFRS (Hemorrhagic Fever with Renal Syndrome) and HPS (Hantavirus Pulmonary Syndrome). The former was discovered during the Korean War, while the biggest outbreak of the latter was in 1993 in the Southwestern United States.

Severe cases of HFRS might lead to acute kidney failure while HPS fills lungs with fluid, a condition known as edema. While the mortality rate of HFRS varies from 1 to 15 percent, HPS has an alarming fatality rate of 38 percent.



6. Rabies


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The history of rabies goes way back to 2300 BC, with records about Babylonian folks who went crazy and died post being bitten by dogs. Thanks to the modern medicine, it’s possible to completely ward-off the lethal virus by means of immediate vaccination treatment. However, the virus is fatal in the absence of an immediate medical treatment.

When left untreated, rabies virus attacks the central nervous system. Delirium, hallucinations and violent behavior are dominant symptoms of rabies virus. Though the death toll from rabies has subsided over the years, it still contributes to several thousands of premature deaths around the globe.


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5. Lujo Virus


With a fatality rate of 80%, Lujo virus is one of the most deadly viruses in the world. The etymology of the virus consists of Lu and jo. While the former represents Lusaka (a location in Zambia), the latter represents Johannesburg (in South Africa). The virus was named after a breakout at the two locations in 2008.

The virus not only affects humans but animals too. In humans, Lujo Virus causes VHF (Viral Hemorrhagic Fever). The virus not only causes symptoms similar to the Ebola virus, like bleeding nose and gum but falls into the same fatality category as that of the notorious Ebola virus.


4. Influenza A Virus Subtype H5N1


Also known as the Bird Flu virus, the Influenza A Virus Subtype H5N1 is a terminal virus. It is number 4 on our list of top 10 deadliest viruses in the world. Since its first infection in 1997, Influenza A Virus Subtype H5N1 has killed about 60% of all infected patients. Transmitted by birds to humans, a research suggests that the virus triggers 10 times more inflammatory proteins than the H1N1 virus.

This leads to acute respiratory distress and life-threatening pneumonia. In severe cases, the virus might lead to multi-organ failures. Other than the prevalent respiratory complications caused by Influenza A Virus Subtype H5N1, it triggers several flu-like symptoms, including diarrhea and vomiting.



3. Marburg Virus


Untreated patients suffering from Marburg Virus has a mortality rate of 23 to 90%. The virus is responsible for leading to the fatal Marburg Hemorrhagic Fever, also known as the Marburg Virus Disease. Even though the virus causes hemorrhage (or blood loss), the most common cause of death in patients suffering from Marburg Virus Disease is MODS i.e. Multiple Organ Dysfunction Syndrome.

The first Marburg Virus outbreak resulted in 1967 at Germany’s Frankfurt and Marburg laboratories. Out of a total of 31 patients, 7 died. Displeasingly, survivors of the disease experienced prolonged hearing loss, muscles weakness, ocular problems, hepatitis, and several other distressing medical conditions.


2. Herpes B Virus


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With a fatality rate of 80%, Herpes B Virus is yet another deadliest virus on the planet. It is the runner-up on our list of top 10 deadliest viruses in the world. Found in the macaque monkeys, the virus travels from one host to another by means of the peripheral nerves. Primarily affecting the central nervous system, a contraction to Herpes B Virus might result in a severe nervous breakdown and even death when left untreated.

Since its discovery in 1932, there have been 31 documented cases of Herpes B Virus. Sadly, 21 of these resulted in death. Though contracting the virus is rare among humans, it can easily transfer from monkey or animals. Fever, muscle in-coordination and shortness of breath are some of the distinctive symptoms of the fatal viral infection.


1. HIV (Human Immunodeficiency Virus)


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Human Immunodeficiency Virus, or infamously known as HIV, contributes to millions of deaths each year. And of course, it is the number 1 entry on our list of top 10 deadliest viruses in the world. While not an angel of death itself, the HIV shuts down cells responsible for keeping the immune system active. Contracting HIV leads to an incurable condition, known as the Acquired Immunodeficiency Syndrome or AIDS. HIV targets CD4 lymphocyte, a special type of immune cell in the body.

Typically, patients with HIV die from severe cases of respiratory infections like pneumonia and tuberculosis. HIV, kind of, leads to slow death. People suffering from asthma and diabetes are likely to be killed sooner than other. In some scenarios, HIV might lead to the generation of cancers too. For now, there is no cure for HIV. Nonetheless, early detection of HIV can assist in prolonging life.




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