A-34 year old person has rapidly developing cough, dyspnoea, expectoration and blood tinged sputum. He is febrile cyanosed and toxic.Chest examination reveals crepitation and rhonchi. The most likely diagnosis is -

Ans. is 'b' i.e., Pneumonic plague . Radidly developing cough, dyspnea, blood tinged sputum with fever and cyanosis is the classical presentation of pneumonic plague. About other options Option 'a' . Legionnaires pneumonia presents as mild cough, only slight production of cough . There is associated diarrhea and neurological abnormalities. . There is no cyanosis Option 'c' Usually in septicemic plague respiratory symptoms do not occur. Option 'd' . Tuberculosis has gradual course.