NEW DELHI: Cabinet Secretary Rajiv Gauba has told state governments that more than 15 lakh international travellers came to India over the last two months but there appears to be a gap between the actual monitoring for Covid-19 and the total arrivals.In a letter to chief secretaries of all states and Union territories, Gauba said such a gap in monitoring of international passengers may seriously jeopardise the efforts to contain the spread of the novel coronavirus , given that many amongst the persons who have tested positive for the virus so far in India have a history of international travel.