 - lower respiratory tract infections: new pulmonary infiltrate in the presence of: i at least one respiratory symptom cough, sputum production, dyspnea, pleuritic pain with ii at least one finding on auscultation rales or crepitation or one sign of infection core body temperature 38_C or less than 36_C, shivering, or leukocyte count 10,000mm3 or 4,000mm3 in the absence of antibiotics 