There are more than three hundred thousand different types of viruses that pose a danger to humans, causing various diseases. Among them there are weak specimens that cause only short-term illnesses. But as a result of natural selection, some viruses have become real killers: they have learned to spread with great speed and cause serious consequences. There are several dangerous viruses among which it is difficult to name a winner.
Influenza viruses
There are many different influenza viruses, and it is this group that is considered one of the most dangerous to humans, since in the entire history of its development, influenza has claimed more lives than any other virus. For example, the famous "Spanish flu" at the beginning of the XX century led to the death of about fifty million people. At the same time, the Spanish flu was transmitted very easily and quickly - with the help of the slightest amount of saliva or mucus secreted when coughing.
Some types of influenza can change so quickly that humans or animals do not have time to acquire immunity. Influenza A (orthomyxovirus) epidemics kill hundreds of thousands of people every year. Periodically, this virus mutates, leading to major pandemics - the most global and was the "Spanish flu" in 1918.
Plague stick
Plague bacillus is a very dangerous virus for humans, which claimed millions of lives several centuries ago. During the plague pandemic, about half of the total population of the contaminated regions died. In the middle of the XIV century, the world's population fell by as much as one hundred million people only thanks to this terrible virus.
But with the invention of antibiotics, the plague bacillus became less dangerous, now the plague is being treated, although outbreaks of infection are still found in some areas.
HIV
The human immunodeficiency virus is one of the main enemies of mankind. During its existence, it killed about twenty million people - not nearly as many as the plague or the flu, but the lack of effective treatment for this disease still makes this virus so dangerous. So far, medicine can only slow down and stop the progression of infection, postponing the onset of the last stage - AIDS.
But the virus is constantly mutating, so you have to change the treatment regimens, and sooner or later the therapy turns out to be ineffective, and the person dies.
Ebola virus
The Ebola virus is called one of the most dangerous for humans, as it develops at a record speed, killing in just two days. It is transmitted by airborne droplets, along with blood and other fluids, its incubation period lasts up to three weeks, but as soon as the virus begins to develop in the body, it causes very rapid and severe damage to it. Patients have vomiting, dehydration, bleeding, mental damage. Literally in a matter of hours, the psyche is destroyed, the flesh decomposes, the internal organs become jelly-like. There is no vaccine against this virus, and there is no specific treatment. In some cases, a person recovers, but certain types of the Ebola virus are fatal in 90% of cases.
