Diagnostic Utility of Mycobacterium Tuberculosis Cell-free DNA in Hong Kong

Inclusion Criteria: * Patients hospitalised for new-onset unilateral pleural effusion. * Thoracentesis will be performed for pleural fluid analysis. * Age equals or is above 18 years old * Written informed consent is obtained Exclusion Criteria: * History of intrapleural therapy (including talc and fibrinolytic), surgical decortication or surgical pleurodesis in the ipsilateral pleural space in the past 3 months * Concomitant use of at least two anti-TB medications (including isoniazid, rifampicin, pyrazinamide, ethambutol, amikacin, streptomycin, levofloxacin, moxifloxacin, linezolid) for more than consecutive 7 days in the past 3 months * Failed to obtain informed consent due to patient's refusal or cognitive impairment. * History of TBP in the ipsilateral pleural space * Expected survival of less than three months from a different pathology (e.g. advanced metastatic malignancy) as that further pleural investigations may not be able to carry out if negative initial workup. * Use of agents under research or not registered in the 30 days prior to the study