National Library of Medicine Still endemic Yersinia pestis Yersinia pestis nlm.nih.gov treated National Institutes of Health MedlinePlus Encyclopedia: Plague bubonic plague causes the plague NIH Medline Encyclopedia Plague Information classic symptoms the disease National Institutes of Health http://www.nlm.nih.gov/medlineplus/ency/article/000596.htm Plague Symptoms classic symptoms Symptoms of bubonic plague MedlinePlus Encyclopedia: Plague MedlinePlus Encyclopedia: Plague National Institutes of Health’s website Plague: a severe and potentially deadly bacterial infection symptoms