What Is the Most Dangerous Virus? 

It is hard to determine what is the most dangerous virus. Some viruses affect a lot of people worldwide such as HIV. Others affect far less people, but have a high fatality rate such as ebola. Certain dangerous viruses were or are in the process of being eradicated.

Viruses are believed to exist ever since life formed on earth for the first time. Just like all species, they adapted and changed and re-invented over the years. Nowadays, some viruses seem to be stronger than ever. They spread from individual to individual and sometimes they become stronger and stronger as they multiply. But what is the most dangerous virus? There is no simple answer to this question.

First of all, viruses can be classified depending on the number of deaths they cause and on the fatality rate. For instance, HIV is responsible for killing 25 million people ever since the early 80s. There is no treatment or vaccine for this virus, but its evolution can be stopped with certain medication. On the other hand, HIV does not necessarily kill all those who get it or at least it doesn't kill them immediately. Ebola is a completely different story. It doesn't affect as many people as HIV, but nearly all those who get it die in a pretty short time frame. This is why it is very difficult to assess the danger than a specific virus poses. The same virus strain might cause different reactions in different individuals. Even if most of Ebola sufferers die in a matter of days, some manage to survive.

Viruses which are responsible for a large number of deaths include rotavirus, hepatitis, influenza, rabies, dengue fever and human papillomavirus. Even though some of these viruses can be kept under control with vaccines, there are still third world countries where they pose special problems and they kill lots of people. Rotavirus seems to be the most common cause of diarrhea in children worldwide. Influenza is also pretty dangerous even though vaccines are in use for decades. Unfortunately, influenza strains seem to become stronger and stronger by the year and this virus is held responsible for the death of half a million people yearly.

Certain viruses are so dangerous that they have caused repeated epidemics through history. Some of them are thankfully eradicated because of vaccines, but others still make victims. They are not as dangerous as they used to be in ancient times, but they are still a threat. Measles for instance killed five million people in ancient times. Unfortunately, even if vaccines are available, it still kills over 150.000 people yearly. This is also the case with yellow fever. It did a lot of damage in the 18th and 19th century. Efforts are being made to eradicate it, but it still affects 200.000 people yearly. Fortunately only 30.000 of them die.