Case finding in RNTCP is based on which of the following?

According to the guidelines of RNTCP, the first diagnostic impoance is given to the direct smear examination of the sputum. The sputum is collected from those patients who visit the hospital and health centres with the following symptoms: ? Persistent cough of about 3 or 4 weeks duration ? Continuous fever ? Chest pain ? Hemoptysis Ref: Park's Textbook of Preventive and Social Medicine 19th edition; pages 154 - 155; 352 - 357;