Top 10 Most Fatal Viruses and Diseases in the World

Diseases are caused by many kinds of pathogens, including, but not limited to viruses. Viruses are a type of microorganism and a disease depends on the type of cells that they infect in a human body. All types of diseases result in a variety of symptoms. The symptoms can vary depending on the severity of the infection. Some of the common diseases caused by viruses in human include the flu, chickenpox and cold infections. Following is a list of the most potent viruses and the top 10 most fatal diseases that we as the human race know about.





SARS stand for Severe Acute Respiratory Syndrome. It is a severe respiratory virus disease that is caused by Corona virus. The infection of SARS is caused when the droplets from cough or sneeze of the infected person passes to another person’s mouth, nose or eyes through direct interaction or by touching the contaminated surface or object with infectious droplets. SARS was first found in Asia and it spread worldwide rapidly.


Malaria is one of the most serious diseases caused by Plasmodium parasites that infect Anopheles mosquitoes. Such type of mosquitoes feeds on humans. The symptoms at the initial stage include headache, high fever, vomiting, feeling cold or red spots that show the mosquitoes bites. Malaria sometimes has other mild symptoms that are difficult to be identified. If the virus is not treated within a day then it can develop severe illness that may lead to death. There are many countries which are at high risk of malaria transmission.


Cholera is a well-known global problem, caused by an acute abdominal infection that is produced by a bacterium called Vibrio cholera. It has an incubation period of less than a day and can last to five days. The symptoms of Cholera causes painless watery diarrhea that may lead to severe dehydration. If it is not treated in a short period of time then it can also lead to death. Cholera has become a big challenge especially for those countries that are facing problems in providing clean drinking water and sanitation system.

Typhoid Fever

Typhoid fever is a serious fatal disease commonly known all over the world. It is caused by the bacteria known as Salmonella Typhi and this type of bacteria is found in humans only. The symptoms of the typhoid fever include loss of appetite, weakness, headache, high fever and stomach pain. Patients with typhoid fever can be identified by testing for the presence of bacteria in their bloodstream and intestinal area. Antibiotics can deal with minute Typhoid fever.


Polio is abbreviation of Poliomyelitis and is sometimes called infantile paralysis. It is an infectious disease caused by the poliovirus. Polio has no symptoms but the infected person may feel minor headache with fever, vomiting, diarrhea, neck stiffness and pains in the arms and legs. The infection starts causing muscle weakness that results in the inability to move and the most popular weakness is found in legs. The disease may be diagnosed by detecting antibodies in the blood. Preventable can be taken by the use of polio vaccine.



Plague is an infectious disease that is caused by special bacteria known as Yersinia pestis. This deadly disease can spread through air or by direct contact depending on lung infection and sanitary conditions. This can also be caused by using contaminated food that is undercooked or by using contaminated materials. The symptom of this sickness depends on the affected areas and its level of infection in various parts of the body. The lymph nodes, blood vessels and lungs are the main parts of the body that are affected most. The treatment of Plague is possible if it is diagnosed early in time and then it can be treated with highly intensive antibiotic therapy.

Avian Influenza

Avian influenza, also known as Bird Flu, is an infectious viral disease that is transmitted through the direct contact with dead or live poultry and also if you are directly exposed to the contaminated environment of poultry farms or poultry markets. Avian influenza causes severe infection in people and causes a higher fatality rate than seasonal influenza.


Yellow fever and Dengue fever

The Flavi virus causes yellow fever and Dengue fever and both have the same vector (mosquitoes). Both cause hemorrhagic fever. Yellow fever has two stages. The first stage is characterized by headache, fever, back pain, muscle pain, and nausea and in second stage, patients suffer from high fever, abdominal pain with vomiting, jaundice becomes apparent and mouth, eyes and nose start to bleed. It also weakens the kidney function. Dengue fever has the same symptoms as the yellow fever and is a constant threat to all people who visit popular holiday destinations such as Thailand and India. There is no treatment for yellow fever and the infected dies within a few days of contracting it.


HIV is the pathogen behind AIDS and it stands for Human Immunodeficiency Virus. HIV is a universal epidemic disease that is caught with the interaction of blood, semen or vaginal fluid of a HIV infected person. It can also be acquired by sharing sharps invasive materials like needles, blades, knives or dental instruments and even from an HIV-positive mother to her baby. It weakens the ability of a person to fight infections and disease as it directly affects the immune system of a body.

Ebola virus

Ebola virus
Ebola virus

The most deadly disease in the world today is perhaps the Ebola disease. It is the biggest disease in history and is caused by the Ebola virus that is just out of control. Ebola virus has been causing disasters and great fear, especially in the region of Africa. Ebola virus has five strains out of which Zaire Ebola virus is highly contagious and which has a whopping mortality rate of 90 percent. It is transferred through physical interaction or direct contact with blood and secretions of the infected humans and animals.