The Union Health Ministry said on Tuesday that if no Covid-19 case is reported for 28 days from a specific area, only then we can say that we have been successful in breaking the chain of transmission of the dreaded virus. Also Read - Community Transmission of COVID-19 in Clusters? Random Sampling Results by ICMR Reveal Indications

In response to a query on the logic behind extending the nationwide lockdown till May 3, Lav Agarwal, Joint Secretary at the Health Ministry, said “Our major effort is to break the chain of transmission. If there are no cases reported for 28 days from a particular are or the last negative case is reported 28 days ago, then we believe that the chain of transmission has stopped as cases have stopped coming.”

He insisted that the extension of the lockdown, coupled with social distancing as a behavioral change, is important to break the chain of transmission.

The 28-day period has originated from the Ministry of Health and Family Welfare’s containment plan. According to this, the containment plan would only be scaled down if no Covid-19 case confirmed by a secondary laboratory is reported from the geographic quarantine zone for at least four weeks after the last confirmed case has been isolated and all his contacts have been traced for up to 28 days.

“The containment operation shall be deemed to be over 28 days from the discharge of the last confirmed case (following negative test as per the discharge policy) from the designated health facility, i.e., when the follow up of hospital contacts will be complete,” said the ministry in a strategy document.