An Algorithm to Decide on Antibiotic Prescription in Lower Respiratory Tract Infection in Primary Care

"First, procalcitonin will be measured using a rapid point-of-care test. In case of elevated procalcitonin result (≥0.25 µg/L), a lung ultrasound will be performed to look for the presence of a lung infiltrate or consolidation suggesting the presence of community acquired pneumonia. A portable ultrasound machine with a convex probe, that will be provided to the general practitioner by the study, will be used.~The lung ultrasound will be done following international evidence-based recommendations for point-of-care lung ultrasound using the basic eight-region sonographic technique and the criteria for positive scan and positive examination for the diagnosis of pneumonia ."

Procalcitonin will be measured using a rapid point-of-care test

A venous blood sample (17.5 mL) will be collected. Whole blood and plasma will be stored at - 80°C. Further analysis will be performed in order to identify novel biomarkers and gene transcription patterns that could predict the necessity of antibiotic prescription or the severity of disease.

A pooled nasal swab will be performed and sputum will be collected. Samples will be stored at -80°C. Further analysis of the naso-pharyngeal swab and cultures of sputum will be performed to identify by molecular techniques pathogens implicated in the clinical presentation.