This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
It is true regarding endemic typhus that ? 
Select and explain. 
A. Man is the only reservoir of infection, B. Flea is a vector for the disease, C. The rash developing into eschar is a characteristic presentation, D. Culture of the etiological agent in tissue culture is a diagnositc
B: Flea is a vector for the disease
Answer: B: Flea is a vector for the disease 
Explanation: Ans. is 'b' i.e., Flea is a vector for the disease . Endemic typhus is transmitted by the rat flea. . Rats are the major reservoir . There is no eschar in endemic typhus Diagnosis is made by serological test (IFA) or PCR amplification of R typhi DNA from blood -