Bubonic plague

This is the most common form of Yersinia pestis infection and affects about 90% of individuals. The incubation period of this condition is about one week.

• onset of illness: high fever, chills, headache, myalgia, nausea, vomiting. If the illness is severe then there is prostration.
  
  
• sequelae: rapid development of lymphadenopathy (buboes). The inguinal lymph nodes are most commonly involved. These are commonly matted and tender; they suppurate in one to two weeks. Other possible clinical features include petechiae, ecchymoses, and bleeding from the gastrointestinal tract, respiratory tract and genitourinary tract. There is mental confusion after the development of toxaemia.