Short Duration Treatment of Non-severe Community Acquired Pneumonia

Inclusion Criteria: * Subject must be 18 years old or over. * admitted three days before for Community Acquired Pneumonia (CAP) defined by at least one clinical sign of pneumonia (dyspnea, cough, mucopurulent sputum, crackling sound on lungs) associated with a temperature \>38°C on admission, and a new infiltrate consistent with pneumonia on chest x-ray, who responded favorably to 3 days of treatment with β-lactams (third generation injectable cephalosporin or amoxicillin-clavulanate) * able to take oral medication. * has given its informed consent. Exclusion Criteria: * Creatinin \< 30ml/min * History of jaundice / hepatic impairment associated with amoxicillin / clavulanic acid * History of hypersensitivity to beta-lactam * Presence of complications or severity of pneumonia (abscess , significant pleural effusion, severe chronic respiratory failure , septic shock, respiratory condition requiring the passage resuscitation). * Known immunocompromised terrain ( asplenia , neutropenia, agammaglobulinemia , immunosuppressants, graft corticosteroids , myeloma , lymphoma, known HIV , sickle cell anemia , CHILD C cirrhosis). * Antibiotic treatment exceeding 24 hours prior admission. * Suspected atypical bacteria requiring combined antibiotics therapy .(Subjects who received a single dose of macrolides or fluoroquinolones emergency will not be excluded) . * Legionella suspected on clinical, biological and radiological criteria . * Subjects with clinical or epidemiological environment leading to suspect a healthcare-associated pneumonia with antibiotic resistant pathogen. * Suspicion of pneumonia by aspiration. * Intercurrent infection requiring antibiotic treatment. * Pregnant women . * Breastfeeding . * Allergy to antibiotics in use. * Life expectancy \<1 month . * Subject without health insurance. * Subjects without home adress