Asymptomatic. Tuberculosis is contagious because a large proportion of patients with asymptomatic tuberculosis are found at present. It is recommended that once TB is detected, patients with or without symptoms should be careful to wear a mask and not to spit. If the sputum is positive for tuberculosis bacilli, a meal portioning system should be carried out, while dishes should be disinfected and separate housing should be provided until the sputum bacilli turn negative after standard anti-tuberculosis treatment.