<s>[INST] context: Plague, also called Black death or Mahamari or The great death, is a zoonoses caused by yersinia pestis.
Wild rodent (Tetra indica) is the natural reservoir in India. o Most effective and commonest vector for plague is rat flea.
Xenopsylla cheopis is the most important species of rat flea for plague. Other important species are X. astia, X. brasiliensis and Pulex irritans. Both sexes of flea bite and transmit the disease.
A partially blocked flea (a flea with partially blocked proventriculus) is more dangerous than a completely blocked flea.
Rat flea can survive upto 4 years in rat burrows under optimum conditions.
This is considered the most likely mechanism of maintaining the natural focus.
Modes of transmission may be :

Bite of infected flea
Direct contact with tissues of infected animal
Droplet infection (in pneumonic plague),

There are three types of plague :

Bubonic plague (most common type) with incubation period 2-7 days
Pneumonic plague (most virulent and least common) with incubation period 1-3 days
Septicemic plague (less infectious) with incubation period 2-7 days.


Streptomycin is the drug of choice for treatment and tetracycline is the drug of choice for chemoprophylaxis. [/INST] question: Plague is transmitted by the bite of | options: A: Rat flea B: Culex mosquito C: Body louse D: Tse-Tse fly | answer: A </s>