PTB refers to any bacteriologically confirmed or clinically diagnosed case of TB involving the lung parenchyma or tracheobronchial tree. Tuberculous mediastinal and/or hilar intrathoracic lymphadenopathy is also classified as PTB, following an expert consultation convened by WHO in September 2021.15 Miliary TB is classified as PTB because there are lesions in the lungs. Tuberculous pleural effusion without radiographic abnormalities in the lungs constitutes EPTB. A person with both PTB and EPTB should be classified as having PTB (71).
15 In children aged under 10 years; further updates to the classification relevant for other age groups are expected in 2022.