In the diagnosis of respiratory tract infections and monitoring of bacterial sepsis, inflammatory markers, such as C reactive protein (CRP) and procalcitonin (PCT) in blood, have proven useful to guide antibiotic therapy and reduce antibiotic use.18–21 Currently, point-of-care (POC) CRP measurements are recommended by Dutch guidelines for the general practitioners to guide antibiotic treatment for acute respiratory tract infections. This evidence concerns the gene CRP and Respiratory tract infection.