3.2 Classification of TB

The TB Cases are categorised in to Pulmonary and Extra Pulmonary TB based on the anatomical site of the disease.

Pulmonary TB (PTB)

Pulmonary tuberculosis (PTB) refers to any bacteriologically confirmed or clinically diagnosed case of TB involving the lung parenchyma or the tracheobronchial tree. Miliary TB is classified as PTB because there are lesions in the lungs. Tuberculous intra-thoracic lymphadenopathy (mediastinal and/or hilar) or tuberculous pleural effusion, without radiographic abnormalities in the lungs, constitutes a case of extra-pulmonary TB. A patient with both pulmonary and extra- pulmonary TB should be classified as a case of PTB.

Extra-pulmonary TB (EP TB)

Extra-pulmonary tuberculosis (EPTB) is any bacteriologically confirmed or clinically diagnosed case of TB involving organs other than the lungs such as pleura, lymph nodes (mediastinal, hilar, cervical etc.), larynx, meninges, abdomen, genitourinary tract, spine, bones and joints, skin etc.

New: A patient who has never taken treatment for TB or a patient who has taken anti-tuberculosis drugs for less than one month. New patients may have positive or negative bacteriology and may have disease at any anatomical site.

Previously Treated: A patient who has received anti-TB drugs for one month or more in the past. Based on the outcome of their most recent course of treatment, they are sub-classified as relapse, treatment after failure, treatment after loss to follow up and other previously treated.

HIV- positive TB patient

Refers to any bacteriologically confirmed or clinically diagnosed case of TB who has a positive result from HIV testing conducted at the time of TB diagnosis or other documented evidence of enrolment in HIV care, such as enrolment in the pre-ART register or in the ART register once ART has been started.

HIV-negative TB patient

Refers to any bacteriologically confirmed or clinically diagnosed case of TB who has a negative result from HIV testing conducted at the time of TB diagnosis. Any HIV-negative TB patient, subsequently found to be HIV-positive should be reclassified accordingly.

HIV status unknown TB patient

Refers to any bacteriologically confirmed or clinically diagnosed case of TB who has no result of HIV testing and no other documented evidence of enrolment in HIV care. If the patient’s HIV status is subsequently determined, he or she should be reclassified accordingly.