An algorithm to improve the diagnosis of pneumonia


Current tests do not allow GPs to determine with sufficient accuracy whether a patient has pneumonia requiring antibiotic therapy. We are increasing the precision of diagnosis by combining two new diagnostic tests with an algorithm.

Portrait / project description (ongoing research project)

General practitioners too often prescribe antibiotics for acute respiratory tract infections because they cannot distinguish between bacterial pneumonia and non-bacterial infections. In order to improve diagnosis we are developing a procedure that combines ultrasound examination of the lungs with a procalcitonin test helping in differentiating between bacterial and viral infections. However, since each method on its own produces too many unreliable diagnoses, we are combining their results with an algorithm to increase diagnostic precision. In our study, several general practitioners are using this strategy, and we are comparing the amount of antibiotics they prescribe and the therapeutic outcomes with those of a comparator group who are not using the strategy.


Acute respiratory tract infections are among the most frequent reasons for unnecessary prescription of antibiotics. Use of these medicines for these infections needs to be reduced.


Our aim is to develop a low-cost, practicable method capable of determining with greater precision than in the past which patients with respiratory tract infections have pneumonia that requires treatment with antibiotics.


Since our method requires only a small mobile ultrasound and a rapid, easy-to-perform test, it is suitable for a wide variety of settings and could be widely deployed very rapidly. We are also asking the doctors taking part in our study about criteria which tend to favour or hinder the use of the method.

Original title

Procalcitonin and lung ultrasonography point-of-care testing to decide on antibiotic prescription in patients with lower respiratory tract infection at primary care level: cluster randomised trial

Project leaders

  • Dr. Noémie Boillat Blanco, Service des maladies infectieuses, Centre Hospitalier Universitaire Vaudois, Lausanne
  • Dr. Andreas Kronenberg, Institut für Infektionskrankheiten Universität Bern, Bern
  • Dr. Valérie D'Acremont, Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel
  • Dr Nicolas Senn, Policlinique Médicale Universitaire PMU, Lausanne



Further information on this content



Dr Noémie Boillat Blanco Service des maladies infectieuses
Centre Hospitalier Universitaire Vaudois
Rue du Bugnon 46 1011 Lausanne +41 79 556 16 86