NEW DELHI: An ICMR study has found that a COVID-19 patient can infect 406 people in 30 days if preventive measures such as lockdown and social distancing are not implemented, the Union health ministry said on Tuesday.With preventive measures in place, the possibility of the infection can be reduced to an average of just two-and-a-half persons per patient in the same period, Joint Secretary in the Ministry of Health Lav Agarwal said.Citing the Indian Council of Medical Research (ICMR) study, Agarwal said that the current 'R0' or R naught for the coronavirus infection is somewhere between 1.5 and 4.'R0' is a mathematical term that indicates how contagious an infectious disease is. It tells the average number of people who will catch a disease from one infected person."If we take the 'R0' to be 2.5 then one positive person can infect 406 people in 30 days, if the lockdown and social distancing measures are not in place, but if social exposure is reduced by 75 per cent then that one sick person will only be able to infect only 2.5 persons," Agarwal said, highlighting the importance of the ongoing 21-day lockdown and social distancing.He appealed to the people to adopt social distancing and follow the lockdown order, saying this is a very important intervention in terms of management of COVID-19.The death toll due to novel coronavirus rose to 114 and the number of cases in the country climbed to 4,421 on Tuesday, according to the Union Health Ministry.