The term pandemic it comes from a Greek word that means “Town meeting” and whose significance has been extended as "Sickness of all the people" . It is a disease epidemic that affects various countries and that attacks almost every people of a geographical region.
The epidemics they are diseases that affect many people simultaneously as they spread over a certain period of time in a certain area. These epidemiological outbreaks make the level of incidence of a disease higher than expected by specialists (there are more patients than expected).
There are three conditions that generally must be met for a pandemic to appear. In principle, it must be a virus new that has not circulated in advance. This means that there is no population that has developed an immunity.
On the other hand, the virus must be able to be transmitted from person to person effectively and must be capable of causing a serious illness. The World Health Organization (WHO) distinguishes between various phases that correspond to the stages that a pandemic goes through during its expansion.
The Black Death of the XIV century It is an example of a pandemic. The epidemiological outbreak of bubonic plague began in Asia , then arrived at Mediterranean and finally it expanded by Western Europe before the travel of the merchants. It is estimated that this pandemic killed some twenty million European citizens in six years.
Historically there have been other pandemics that have caused millions of deaths worldwide. This would be the case, for example, of the typhus that also receives the name of “camp fever” since it was common for it to appear in times of warlike conflict. Specifically, in Spain the moment in which more damage caused among the population was during the conflicts that Muslims and Christians had in the area of Granada.
Smallpox or cholera are other such pandemics that have wreaked havoc over the centuries, not forgetting others that appeared at very specific points in the world geography. Among the latter would be the well-known Plague of Athens, which emerged during the Peloponnesian War, or the Hong Kong Flu, which made an appearance in the 1960s.
In the same way, other diseases have also been described as a pandemic by the WHO, such as the case of HIV (Human Immunodeficiency Virus) that is the cause of AIDS. It is a pathology that, among other things, brings about a person's immune system not being able to cope with infections.
The fact that it has spread rapidly throughout the world has been the one that has led the aforementioned international institution to describe it as a pandemic. And it is considered that, only in the African continent, has been able to cause the death of more than twenty million people.
The swine flu , flu A or H1N1 flu It is a pandemic that is still expanding today. The WHO He has stated that the evolution of the virus and its scope cannot yet be predicted.