Jeri: I'll leave you to be the pedant & look it up.

Pedantic me wants to say you can get plague from someone with the pneumonic (pneumonia) form of it, but I don't think someone who had that would be delivering interested in sex, but I'll refrain.

My recollection is that pneumonic form is the more virulent and deadly one. A person may have both p. and bubonic.

But the contageous stage, like most bacterial infections, begins well before the symptomatic one. Seven days, if I recall Bocaccio's scary-vivid description.