Pandemics era

A pandemic generally refers to an outbreak of an infectious disease for which there is no immunity, with global or widespread distribution, in large populations, with local transmission, explosive outbreaks, and a large number of hospitalizations and deaths. The most recent respiratory pandemics were due to influenza AH1N1 in 2009 and COVID-19 in 2020. The main predisposing factors include not only the characteristics of the germ, the host, and the vector, but also factors such as urbanization, overcrowding, agglomerations, and rapid global transport. More fundamentally, the disruption of wildlife habitats, climate change, inadequate health systems, poverty, and socioeconomic inequity are factors that must be considered to prevent or mitigate pandemics. The viruses from recent pandemics continue to circulate sporadically throughout the year, and additionally in seasonal outbreaks during the winter, with a lesser impact due to improved immunity. There has also been talk of pandemics of non-communicable diseases or exposures such as smoking, obesity, or diabetes, which collide with infectious diseases, increasing the risks in what have been called syndemics.