Ramaswami: Cabinet secretary Rajiv Gauba has written to state governments urging them to put under surveillance some 15 lakh travellers who arrived at India’s international airports from January 18 to March 23, and whose details are with the Bureau of Immigration. Not doing so, he says, may seriously jeopardise India’s effort at containing the spread of Covid-19. Presumably these 15 lakh people were screened at airports and advised “home quarantine”. Those under home quarantine advisories have to be “monitored” by the governments of the states they live in. The letter says “there is a gap between the number of international passengers who need to be monitored, and the actual number being monitored…”