How did antibiotics change plague death rates?

The introduction of antibiotics—beginning with sulfonamides in the 1930s—fundamentally transformed the prognosis for those infected with plague. Historically, the disease carried a devastating fatality rate ranging from 50 to 90 percent.1

Modern medical intervention, which relies on the prompt administration of antibiotics such as streptomycin, gentamicin, doxycycline, or ciprofloxacin, has significantly reduced these outcomes. Today, the global fatality rate for plague has been lowered to less than 15 percent. This rate is even lower in cases of bubonic plague and in regions where modern health care is readily available. Because the disease remains potentially fatal if left untreated, early diagnosis and the immediate start of antibiotic therapy are essential to protecting a patient's life.1234