[CA/GK] Various stages for a disease to be declared as "pandemic"

COVID – 19 is a pandemic disease. For a disease to be declared as pandemic, there are four stages.

Stages	Events
Stage – 1	The epidemic disease that eventually takes the form of a pandemic sweeping the globe, cases are imported into a country in which the infection did not originate. An infection whose spread is contained within the boundaries of one or a few countries is obviously not a pandemic.
Stage – 2	When the virus starts being transmitted locally. Local transmission means that the source of the infection is from within a particular area and the trajectory the virus has taken from one person to the next is clearly established.
Stage – 3	Community transmission. community spread is when we do not know the source of the infection — we are unable to trace it back to someone who has travelled in an affected area overseas, or got it through contact with someone who is infected. 80% of population got affected by COVID – 19 by Community transmission
Stage – 4	When the disease becomes endemic in some countries. Among diseases that are currently endemic in India — meaning they occur round the year across the country — are malaria and dengue.