Hyderabad: A viral post accompanied by a graphic claims that there has been a pandemic every 100 years. It claims there was a plague in 1720, a cholera outbreak in 1820, Spanish flu in 1920, and the coronavirus in 2020. So, what is a pandemic? WebMD quotes Dan Epstein, a spokesman for the Pan American Health Organization, as saying, "A pandemic is basically a global epidemic--an epidemic that spreads to more than one continent." FACT CHECK Let's see the timeline of each pandemic outbreak. Plague (1347–1351): According to the National Human Genome Research Institute, "Black Death," a plague that swept through Europe during the 14 th century, killed anywhere between 30-50% of the population. WHO explains that plague is "caused by the bacteria Yersinia pestis, a zoonotic bacterium usually found in small mammals and their fleas'. Cholera (1817–1821): According to one study, "The first pandemic (1817–1821) known as 'Asiatic cholera' began in Je...