Most deadly viruses in the world. Which killed millions of peoples on Earth. Here is the list of most deadly viruses still exists on earth and killing people every day.

Let’s first see Top 5 most deadly viruses which killed many people than any other deadly viruses on earth, these viruses still active and taking many lives day by day. Apart from HIV & Influenza viruses, world has seen many deadly viruses in past such as Small Pox (Virola) which killed many humans before 20th Century, although its controlled now but still fear lies among people. One of the most deadly viruses responsible for pandemic in past history of mankind.

Top 5 most deadly viruses in terms of number deaths caused by Virus.


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When it comes to most deadly viruses then HIV is the king of all deadly viruses if we consider number of human deaths caused by HIV over the years. It stands for Human Immune Virus which causes AIDS (Acquired Immune Deficiency Syndrome) over period of time. Average survival time after infection is 9 to 12 years depending on various factors, that’s why it’s called silent killer of society like Cancer. HIV infected humans found in all countries across. Still there are many patients are dying and getting infecting by HIV. There are two types.  HIV-1 found Globally & HIV-2 mostly in West Africa.

HIV Symptoms & Cause of Death

Most common symptoms are- Feeling tired all the time, long lasting fevers, Loss of appetite, sweating in night etc. In many cases symptoms are vague so it’s always better to do testing to know infection. Basically it destroys immune system and makes human body as a hot spot for all other diseases where recovery is not possible due to low immune system. Eventually that becomes reason of death.

Transmission of HIV

Most of the time it transmitted through condom less sexual intercourse between two partners where potential body fluids like semen, vaginal fluids and pre ejaculate which carries sufficient amount viral load. It also transmits through blood of infected person.

Mortality Rate of HIV

Few years back mortality rate was almost 80 % but now it’s decreasing day by day due to effective treatment therapy.

Treatment of HIV

 No cure, Because, There is no perfect cure or vaccine available for HIV. But there are some Anitretroviral drugs (ART- Anitretroviral Therapy) which controls infection and increases life spam of infected patients. If treatment given in early stages then are chances patient can live longer.

2-Influenza- (H1N1, H1N2, H3N1, H3N2, H2N3)

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Influenza is second most deadly viruses when it comes to total number deaths caused by family of these viruses. It is also known as Swine Flu It was responsible to take many human lives in past. Still millions of people gets infected and die across the world very year. WHO declared H1N1 as pandemic during outbreak in 2009. Influenza virus classified into Type A, Type B & Type C. This highly reactive virus, it shows symptoms within 2 days to 6 days once infected. However this virus still active and still circulating across the world and causing seasonal flu.

Influenza was responsible for major outbreaks in human history like Spanish Flu . which was one of the deadliest outbreak in human history, where millions of people died during 1918-1990 in Spain.

Influenza Symptoms & Cause of Death

Major symptoms are feeling tired, runny nose, headache, sore throat & severe body pain. Most common cause of death is respiratory failure and key organ failure due to lack of oxygen.

Transmission of Influenza

Influenza spreads through air by coughing or sneezing of infected person & touching the things which is contaminated by virus.

Fatality Rate of Influenza

Mortality rate range is 0.001 to 0.007 % as per CDC of world population in initial breakout in 2009. It may be very less but the numbers of infections are very high as compared to other viruses.

Ebola Virus (EVD)

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This virus is most deadly in terms of mortality rate. It has killed around 50% of patients whoever got infected. So it is among most deadly viruses known to mankind. It was first discovered in 1976 in South Sudan.

Ebola Virus Symptoms & Cause of Death

It causes viral hemorrhagic fever. It shows its effects between 2 Days to 3 weeks time. Key symptoms are Fever, Muscle pain, sore throat, Dehydration, Vomiting. Its mainly reduces body fluids which results in key organ failures like Kidney & liver in most of cases.

Transmission of Ebola Virus

Ebola virus spreads through body fluids of infected person such as blood, semen and breast milk or any items which came in contact with infected personas body fluids. Good thing is it doesn’t transmit through air. However after recovery also infected patients will carry virus in their body fluids for months.

Fatality Rate of Ebola Virus

Over all average of death rate is 50 % as per WHO. It means out of 10 infected persons 5 most likely die. During 2014-16 Ebola outbreaks in West Africa, it was responsible for 11,325 deaths.

Treatment of Ebola Virus

There many companies who are working on Vaccines for Ebola. First vaccine which is approved and used on humans is rVSV-ZEBOV.

Corona Viruses – [COVID-19 & SARS COV]

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In future, this virus has potential to be first when it comes to most deadly viruses. COVID-19 & SARS COV caused major outbreaks recent times. Newly discovered Corona virus officially renamed as COVID-19 from Novel Corona virus. As of now there is no evidence of its source and its transmission in humans.

It’s spreading all over world at rapid pace. Many countries are working round the clock to stop its further spread, as this virus has already killed more than 2.2 Lakhs humans in very short period of time. It forced all countries to adapt Global lock-down, which damaged global economy and many people lost jobs.

Treatment of Corona Virus

Basically there is no proven medical treatment available to treat the Corona Virus disease. Since there are no antibiotics, anti viral drugs and vaccines available to treat corona patient so best chance of survival is knowing infection in early stage and taking medical help. As its spreading fast so social distancing is the only prevention.

Transmission of Corona virus

Transmission of Corona virus happens humans to humans through direct contact or through air. It transmits through coughing; sneezing, talking and touching infected person. It also transmits through air. Corona virus attacks your lungs once it goes inside through windpipe. It can survive on surfaces for almost 9 to 10 hrs. As of now no one is sure about suitable climate condition for virus survival.

What Corona virus causes?

This virus cause Severe Acute Respiratory Syndrome [SARS] which is pneumonia condition where patient will have difficulty in breathing and shortness of breath. It attacks your lungs and damages infected patient lungs. In severe infection cases patient needs ventilator support and intensive care. Also there is possibility of organ failure in severe infection cases. Then eventually death if patient doesn’t recover on time.

Symptoms of Corona Virus or COVID-19

  • Cough
  • Fever
  • Shortness of breath
  • Difficulty in breathing
  • Flu like symptoms

List of most deadly viruses based on fatality rate/mortality rate.


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It is also known as Marburg virus. It is top on most deadly viruses when it comes to Mortality rate.

MARV first identified in 1967, post that there were many outbreaks till 2017. It is most deadly when it comes to mortality rate. Two major outbreaks recorded with MARV, one during 2004-2005 in Angola which killed 90% of infected humans and another one during 2008-2010 in Republic of Congo killed 83% as per WHO stats.

No approved vaccines available to treat MARV. Few experimental vaccines tested on animals but none of them approved or licensed for human usage as of now.

It spreads through one of species of fruits bats and through body fluids of infected person. It can also transmit through unprotected sex.

2- Orthohanta virus

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It is also known as Hanta virus. Hanta virus is second on list when it comes to most deadly viruses based on mortality rate. It has mortality almost 36 % as per CDC . It causes HPS (Hantavirus Pulmonary Syndrome. This virus was discovered in 1976. It is mostly found in mammals like Rats, Chipmunks, Rabbits, Dogs, and Guinea Pigs.

It spreads through body fluids of these mammals. Like Saliva and urine. If any of these mammals carrying virus can infect humans after coming in contact with them. To prevent infection from these mammals, human should keep minimum contact at home or any place where these mammals found.

For treatment Ribavirin drug useful but its effectiveness not known very well. Supporting treatment can help to recover faster.

3- Rotavirus – Diarrhea

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Rotavirus is third on list when it comes to most deadly viruses based on mortality rate. It has mortality of 5% in children less than 5 years who got infection from Rotavirus. It causes Diarrhea fever in children and infants. Almost every child gets infection of Rotavirus at least once in their childhood. It was officially discovered in 1973.

India, Nigeria & Pakistan records maximum Rotavirus infections every year. It transmits through oral contact, infected hands and objects from infected person. Common symptoms are nausea, omitting ad mild fever.

There is no vaccine or drug to treat Rotavirus. It caused severe dehydration, so managing dehydration is the key part of treatment. As part of treatment, more water which has salt, sugar and zinc to avoid dehydration.

4- ZIKV- Zika Virus

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First human infection of Zika Virus was discovered in 1952. ZIKV is fourth on list when it comes to most deadly viruses based on mortality rate. ZIKV has mortality rate of almost 9%. It is named after Zika forest which located in Uganda, as it was found initially in 1947. ZIKV virus causes Zika fever, which is similar to Dengue fever.

Zika virus spreads majorly through Mosquitoes. Sexual contact and blood transmission can cause transmission between human to human. There is no specific vaccine or drug to treat Zika virus. As of now effective treatment is Paracetamol to recover from Zika fever. In severe infection cases hospitalisation is necessary.


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Full form of MERS is Middle East Respiratory Syndrome. In Middle East countries they called it – Camel Flu. MERS is fifth on list when it comes to most deadly viruses based on mortality rate. It was first discovered in 2012 in Saudi Arabia. It is believed that it is originated from Bats. Then bats might have infected camels and from Camels Humans got infected.

Mortality rate can vary based on age of infected person from 0 to 50 %. There is no vaccine and drug available to treat MERS-COV.

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Millions of people lost life during Plague pandemic in past. Bacteria Yersinia Pestis Bacterium was responsible for it. Not the virus. Do you know difference between Bacteria and Virus. Checkout Difference between Bacteria and Virus. You can keep yourself protected from these viruses by following various health guidelines. For example, wearing masks during pandemic. Understand more about N95 Masks or Smart Mask.