Pandemic is a term used to describe an epidemic disease that spreads through several countries in the world simultaneously. To avoid confusion, it is important to clarify the concepts of “endemic infections” and “epidemics”, which have a different meaning from that of pandemic.
Endemic infections occur permanently in a given area for a long time, such as diseases like chickenpox – in several countries cases are reported every year – or malaria in some parts of Africa.
An epidemic, on the other hand, is an increase in the number of cases of a disease followed by a peak and then a drop in the number of that disease.
To make it clearer, a pandemic is occurring around the world, or almost around the world, more or less simultaneously. Some cases of pandemics that have affected humanity were the influenza that began in Mexico in 2009 – an influenza pandemic – or HIV/AIDS – sexually transmitted – that registered its first cases in the 1980s.