TB or not TB, that is the question

A 56-year-old male nursing home resident is sent to the ED by his GP for suspected pulmonary tuberculosis. 

He is a nonsmoker presents with lung infiltrates, wheezing and night sweats. He describes a two-month history of a 7kg weight loss, accompanied by night sweats and dry cough.

His initial chest radiograph shows extensive bilateral, patchy, consolidative infiltrates, involving all lobes peripherally, and most prominent in the upper lobes (figure 1 below).

He has never smoked, and his only significant past medical history is thyrotoxicosis diagnosed in 2009, for which he took carbimazole until two months before presentation.

Despite having a mild intellectual disability, he is physically