system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
The type of transmission involved in the case of plague in rat flea-
assistant
The correct answer is  propagative life cycle is the one in which the agent merely multiplies in vector ,but no change in form that is in the case of plague bacilli in rat fleas.parks textbokk,22 nd ed,pg no 94