Explained: Four stages of an outbreak

An IE report explains the four stages of a pandemic

THE FIRST STAGE, according to the report, is when cases of an infection are imported into a country which was not the source of the infection. In this case, all the countries outside of China which started reporting cases of coronavirus, reached Stage 1 of the outbreak as soon as they reported their first case. If an infection is contained after transmission to only a few countries, it does not become a pandemic, but if it cannot be contained in a short span of time and spreads across the globe, like COVID-19 did, it becomes a pandemic.

THE SECOND STAGE of an outbreak is when there are cases of local transmission in the country, the report explains. 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.

Community transmission is THE THIRD STAGE of an outbreak. In this stage, according to the report, it becomes hard to track the chain of transmission of the virus in a large number of cases. This means that the virus has started circulating within the community and can also infect those individuals who have neither travelled to a country affected by the outbreak nor have come into the contact of a person infected by the virus. In this case, a lockdown becomes highly important as any person can spread the virus, regardless of their travel history or the people they have come in contact with.

THE FOURTH STAGE of an outbreak is when an infection becomes endemic in some countries and keeps resurfacing round the year, like malaria and dengue in India. This is a stage that the Indian government has taken into account in its plan to tackle the virus, the IE report states.

These stages of an outbreak remain uniform across the world to make coordination and understanding simpler, so that countries can be prepared accordingly.