The bubonic plague has an antibiotic now, but the side effects are awful, we also know how to control the fleas which carry it, and it is tough to spread in decent sanitation levels. But bubonic plague is at the same class as a disease as Ebola is: class 4. Plague is still dangerous even with the antibiotic.
So I used my rose and flower spray which contains imidicloprid. It took two applications but that did the trick. Luckily I got on it before they multiplied like they used to.
As far as I am concerned, fleas are a plague.