Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus.
There are four stages of corona virus.
In the first stage of a pandemic, the disease doesn’t spread locally - cases reported are usually people who have had travel history to an already affected country.
The second stage , This means that the person from whom the infection spread to another person is from the country itself. In this stage, the trajectory of the virus can be identified from the source to all the infected individuals.While there are no cases of community transmission in India, local transmission is rampant, with at least 415 confirmed cases of coronavirus having been reported from at least 23 states and Union Territories.
The third stage is when the source of the infection is untraceable; this stage is identified by people who haven’t had travel history getting affected by the virus - once here spread is extremely contagious and difficult to control.
So far, China has been the only country to experience Stage 4, where spread is practically uncontrollable and there are many major clusters of infection all over the country.
These stages of an outbreak remain uniform across the world to make coordination and understanding simpler, so that countries can be prepared accordingly. Such a categorisation makes it easier for other countries to impose measures that they think will benefit, like India imposing travel restrictions on China quite early in the outbreak. This was because, the report states, at that point of time all the cases of coronavirus in other countries were being imported from China. When the instances of cases being imported from other countries started surfacing, India took a proactive measure of imposing travel restrictions on all such countries and it also started universal screening. Now, as the virus has spread to at least 177 countries, India has banned all incoming international passenger flights, locking down the country from the rest of the world .