A strong positive PPD test refers to the possibility of active tuberculosis, but of course it is not absolute. For people with a strong positive PPD test, the first step is to do a CT lung examination to see if there are any lesions in the lungs. If there are suspected TB lesions in the lungs, further sputum examination is needed, that is, sputum for antacid bacilli. If it is clear that it is tuberculosis based on sputum examination, regular anti-tuberculosis treatment is needed. If it is not clear, further bronchoscopy or lung puncture can be done, etc. If there is no problem with CT of the lung, but the patient has a history of close contact with tuberculosis or other TB patients, oral isoniazid can also be administered for treatment.