The “coughing plague” is extremely lethal. If it goes untreated, the mortality rate in its victims is between 95 and 100 percent. No one survives untreated septicemic plague, the third form of the disease. The shocklike movement of massive amounts of plague bacilli directly into the blood system creates such enormous toxicity that even insects normally incapable of transmitting Y. pestis, such as body lice, can become disease vectors. During one outbreak of septicemic plague in the early twentieth century, the average survival time from onset of symptoms to death was 14.5 hours.
