Can canine olfactory screening be of value in the biological surveillance of SARS-CoV-2 infection, in addition to the currently recommended diagnostic methods? Screening is based on the ability of dogs to recognize volatile organic compounds generated by cells during some diseases and especially viral infections such as SARS-CoV-2 infections.

The High Council for Public Health (HCSP) analyses the validity of canine olfactory screening at the request of the Directorate General for Health.

After a few reminders on the conventional methods of diagnosing SARS-CoV-2 infection, the HCSP carried out an in-depth analysis of the international scientific literature on the conditions of implementation and proof of concept of this original screening method. All the available studies highlight the good sensitivities and specificities of the screening when used under experimental conditions with sample collection and delayed analysis of results using well-trained dogs. Field experiments (hospital, metro, airport, university, etc.) are much less numerous and have not, for the time being, led to any permanent implementation of this screening method.

At the end of this analysis, the HCSP summarizes the advantages, limitations and uncertainties in relation to DBS. The HCSP acknowledges that this screening method is an interesting tool, particularly in situations where conventional sampling is difficult to carry out (but with feasibility and positioning to be assessed). However, the HCSP is not able to identify situations where screening would meet a need for screening not covered by conventional techniques and cannot, at this stage of the Covid-19 pandemic, recommend its use for mass or routine screening.

Consequently, the HCSP recommends that research on screening be continued in order to better position this technology in the armamentarium of future screening tools for emerging infections. In particular, this research could eventually lead to the use of biosensors or "electronic noses" and thus avoid the constraints associated with the use of animals.