Symptoms of bubonic plague usually appear 2 to 5 days after exposure to the bacteria, but can occur from a few hours to 12 days later. They start abruptly with chills and a fever up to 41 ° C. Heartbeats become fast and weak and blood pressure can fall. The anus appears at the same time or soon after the fever and is usually painful to the palpation.
The plague caused by Yersinia pestis infection may be bubonic, pneumonic, septicemic or minor pestis, and the symptoms vary according to the type of plague. There may be restlessness, delirium, mental confusion, and loss of motor coordination. The liver and spleen may increase in volume.
More than half of the untreated individuals die between the third and fifth day after the onset of symptoms.
