Could a virus exterminate the human race and cause zombies apocalypse? As impossible as it may seem, the answer to this question is yes. Some diseases could in fact cause very serious epidemics that would quickly lead to the disappearance of human civilization, at least as we know it today.
Let us see some examples.
Zombies Apocalypse Diseases: Sleeping Sickness
According to the BBC, sleeping sickness makes people act like zombies. Caused by the parasite Trypanosoma brucei and transmitted by the tse-tse fly, it is a common disease in Africa.
According to Professor Sanjeev Krishna of the University of London, initially it can cause headaches, muscle aches and, perhaps, itching. But in the later stages, when the parasites have invaded the brain, the victims have difficulty concentrating and they become irritable. Moreover, they start having difficulties when speaking and stop eating. They cannot sleep at night and vice versa, it becomes almost impossible for them to stay awake during the day. So, in the end, their way of behaving resembles that of zombies.
Rabies is perhaps one of the worst diseases that can affect human beings. The symptoms of a person infected with rabies are quite easy to detect. Madness takes possession of the sick person who worsens to a real state of delirium.
These symptoms are very close to those described in Zombies Apocalypse. The disease is transmitted through a bite of an infected person, the person bitten begins to lose reason until he is overwhelmed by the desire to bite another person. This virus causes a severe inflammation of the brain and about 55,000 people die each year of rabies. The disease condemns the victims to become metaphorically undead. Consequences include total or partial paralysis, mental deterioration, agitation, bizarre behavior, mania and delirium. Transmission between humans, however, is extremely rare.
Necrosis is a Greek word whose original meaning was linked to corpses and death. In reality, necrosis is not a disease in itself, but a condition that can be derived from serious injury, intoxication or infection. The skin of a person suffering from necrosis begins to die little by little, even though brain functions continue to be healthy. The patient may, therefore, somehow resemble a zombie.
Necrosis triggers a series of events that can lead to even greater negative effects outside the affected area. Dead tissue stops sending signals to the nervous system and necrotic cells can release dangerous chemicals. It can begin to spread throughout the body and become fatal. Necrosis is not contagious, so it could not be the cause of a zombie epidemic.
Leprosy and Zombies Apocalypse
Leprosy has been a widespread disease for many years. Although almost completely eradicated, there have been cases of leprosy still today in Eurasia and North Africa. Among zombies and lepers there is one common feature: decaying flesh.