But it seems that the Government had a true account of it but all was kept very private.

From A Journal of the Plague Year by Daniel Defoe.  

We had no such thing as printed newspapers in those days to spread rumours and reports of things, and to improve them by the invention of men, as I have lived to see practised since. But such things as these were gathered from the letters of merchants and others who corresponded abroad, and from them was handed about by word of mouth only; so that things did not spread instantly over the whole nation, as they do now. But it seems that the Government had a true account of it, and several councils were held about ways to prevent its coming over; but all was kept very private. Hence it was that this rumour died off again, and people began to forget it as a thing we were very little concerned in, and that we hoped was not true; till the latter end of November or the beginning of December 1664 when two men, said to be Frenchmen, died of the plague in Long Acre, or rather at the upper end of Drury Lane. The family they were in endeavoured to conceal it as much as possible, but as it had gotten some vent in the discourse of the neighbourhood, the Secretaries of State got knowledge of it; and concerning themselves to inquire about it, in order to be certain of the truth, two physicians and a surgeon were ordered to go to the house and make inspection. This they did; and finding evident tokens of the sickness upon both the bodies that were dead, they gave their opinions publicly that they died of the plague. Whereupon it was given in to the parish clerk, and he also returned them to the Hall; and it was printed in the weekly bill of mortality in the usual manner, thus—

Plague, 2. Parishes infected, 1. 

Parallels to today:

We have to rely more on rumors than confirmed report.

We can't rely on newspapers.

The Government seems to know more than it is sharing.  Private knowledge of public concern is the established practice.  

The alarm preceded the impact.

There was confusion and deceit in the early days as to what constituted a death from the plague versus.