The dangerous viruses on Earth

Ebola, HIV, dengue, and seasonal flu viruses all have high mortality rates and are a threat to humans.

Marburg virus

Marburg virus.(Photo: Live Science).

Scientists identified the Marburg virus in 1967, when a small disease outbreak in laboratory workers in Germany came into contact with infected monkeys imported from Uganda. Marburg virus resembles Ebola virus in that it causes dengue fever, which means that the patient has high fever and internal bleeding, which can lead to shock, organ failure and death.

Mortality during the first outbreak was 20%, but increased to more than 80% during the 1998-2000 outbreak in the Democratic Republic of Congo and 2005 in Angola, according to the World Health Organization ( WHO).

Ebola virus

Ebola virus.(Photo: Live Science).

The first outbreak of Ebola in humans occurred simultaneously in Sudan and the Democratic Republic of Congo in 1976. Ebola is spread through contact with blood or other body fluids and tissues of infected people or animals. Ebola virus strains are very different in terms of danger level.

The Ebola Reston strain does not even make people sick. But the mortality rate of the Bundibugyo strain is 50% and that of Sudan is 71%. The outbreak in West Africa in early 2014 was the largest and most complex outbreak to date.

Rabies virus

Rabies virus(Photo: Live Science).

Although pet rabies vaccines were introduced in the 1920s, making the disease rare in developed countries, it is still a serious problem in India and parts of Africa.

"Rabies virus destroys the brain and this is really a terrible disease. We have vaccines against rabies. If someone is bitten by an animal infected with rabies virus, we can treat it. However, if it is not treated timely, the risk of death is 100%, " Elke Muhlberger, associate professor of microbiology at Boston University, USA, said.

HIV virus

HIV virus.(Photo: Live Science).

HIV is probably the most dangerous virus in the modern world."This is still the most deadly virus , " said Dr. Amesh Adalja, an infectious disease expert and spokesman for the American Association of Infectious Diseases. An estimated 36 million people have died from HIV since the virus was first identified in the 1980s.

Strong antiviral drugs can help people live with HIV for many years. But the disease continues to strike in low- and middle-income countries, where 95% of new infections are concentrated. About 1 in 20 adults in sub-Saharan Africa is HIV positive, according to WHO.

Smallpox virus

Smallpox virus.(Photo: Live Science).

In 1980, the World Health Assembly declared smallpox was eliminated. But before that, humanity had lost thousands of years of fighting smallpox, the epidemic of every one of three people who died. People who recover from the disease suffer from the sequelae of pitted scars and even blindness.

The smallpox mortality rate is much higher in communities outside of Europe. For example, historians estimate that 90% of the indigenous peoples of the Americas died from smallpox virus brought by Europeans. In the 20th century alone, smallpox claimed the lives of 300 million people.

Hanta virus

Hanta virus.(Photo: Live Science).

Hanta virus pneumonia syndrome (HPS) first gained widespread attention in the United States in 1993 when a healthy young man and fiancée died within a few days after symptoms of shortness of breath. A few months later, a medical specialist isolated the hanta virus from a deer mouse who lives in an infected person's home. More than 600 Americans are infected with the Hanta virus and 36% die, according to the Centers for Disease Control and Prevention.

Hanta virus is not transmitted from person to person. Patients infected by contact with the faeces of mice carrying the virus. Previously, another strain of hanta virus caused an outbreak in the early 1950s during the Korean War, according to research published in 2010 in the journal Clinical Microbiology Reviews. More than 3,000 soldiers were infected and about 12% died.

Seasonal flu virus

Seasonal flu virus.(Photo: Live Science).

During the flu season, around 500,000 people worldwide can die from viral infections, according to WHO. The most deadly flu pandemic, the Spanish flu, started in 1918 and infected 40% of the world's population, killing an estimated 50 million people."I think something like the 1918 pandemic could happen again. If we find a way to enter the human body, the new strain of virus can easily pass from person to person, making people sick. heavy and causing big problems , " Muhlberger expressed concern.

Dengue

Dengue virus.(Photo: Live Science).

Dengue first appeared in the 1950s in the Philippines and Thailand, then spread throughout the tropics and subtropics around the globe. 405 people in the world live in areas where dengue fever becomes a local disease. Diseases spread by this mosquito will spread as the Earth warms.

Dengue contaminates 50 to 100 million people a year, according to WHO. Although dengue mortality is lower than some other viruses, there is currently no vaccine available. Extensive clinical trials for a vaccine developed by French drug maker Sanofi have shown positive results.

Rota virus

Rota virus.(Photo: Live Science).

Rota virus is the cause of severe diarrhea in infants and young children. The virus can spread rapidly through human feces. Children in developed countries rarely die from rotavirus, but the disease still has a high mortality rate in many developing countries. WHO estimated 453,000 children under the age of 5 died from rotavirus in 2008. Currently, countries have introduced two types of vaccines that significantly reduce the number of hospitalizations and deaths.