An Overflowing Scourge, a Desolating Sickness

It shall cover the land in that generation, according to D&C 45:28-35:

And when the times of the Gentiles is come in,

a light shall break forth among them that sit in darkness,

and it shall be the Fulness of my gospel;

But they [who?] receive it not;

for they perceive not the light, and

they turn their hearts from me

because of the precepts [=authoritative rules] of men.

And in that generation shall the times of the Gentiles be fulfilled. [This is now taking place.]

And there shall be men standing in that generation,

that shall not pass until they shall see an overflowing scourge;

for a desolating sickness shall cover the land. [This is apparently next to occur.]

But my disciples shall stand in holy places, and shall not be moved;

but among the wicked, men shall lift up their voices and curse God and die.

And there shall be earthquakes also in divers places,

and many desolations;

Yet men will harden their hearts against me, and

they will take up the sword, one against another, and

they will kill one another.

And now, when I, the Lord, had spoken these words unto my disciples, they were troubled.
And I said unto them: "Be not troubled, for, when all these things shall come to pass, ye may know that the promises which have been made unto you shall be fulfilled."

"Overflowing": What is it flowing over or out of? How?
"Scourge": What does this mean? What is its purpose?
"Desolating": What will it leave behind or result in?
"Sickness": What will be used to scourge?