Study Evaluating the Impact of Using Triplex Rapid Diagnostic Tests (SARS-CoV-2/Influenza/RSV) on Antibiotic Prescribing

Bacterial resistance to antibiotics is a major global public health issue. In France, this resistance is estimated to cause 158,000 infections annually (127,000 to 245,000), including nearly 16,000 invasive infections, and 12,500 deaths per year. The additional cost of antibiotics in France compared to the average for the most virtuous European countries has been estimated at €441 million.

Reducing exposure to antibiotics by limiting their prescription to situations where they are essential is one of the major levers for slowing down the emergence of resistance.

The vast majority of antibiotics are prescribed in outpatient settings (90% of consumption, or 125 million units per year). In France, respiratory tract infections account for 7 out of 10 prescriptions in primary care. However, the majority of respiratory infections are viral in origin (influenza viruses, respiratory syncytial virus (RSV), SARS-CoV-2, but also rhinoviruses, metapneumoviruses, etc.). The clinical presentation of these infections is often non-specific. The lack of microbiological aetiological diagnosis leads to the unnecessary prescription of antibiotics in many cases of viral infections.

The rapid diagnostic tests (TROD) that have recently become available can test for RSV, influenza viruses and SARS-CoV-2 simultaneously. They enable a diagnosis of viral infection to be made during a consultation and should help to avoid the prescription of antibiotics in these situations. In addition, these tests are simple and can be performed routinely (in less than 15 minutes) without the need for specific equipment or technical skills. Reducing inappropriate prescriptions of antibiotic treatments for viral respiratory infections is therefore a public health priority that is likely to have a significant impact on bacterial resistance, but also on the incidence of adverse effects and the costs associated with these treatments.

At the request of the Haute Autorité de Santé (French National Authority for Health), this study aims to estimate the impact of triplex TRODs (SARS-CoV-2/ influenza/RSV detection) on antibiotic prescriptions in the general population in community settings among patients with infectious syndrome, and to produce data (comparative to RT-PCR) to better estimate the diagnostic performance, sensitivity and specificity of the test used in the study.

The participation period for each participating doctor will be determined by random draw, with the aim of ensuring that the start dates of participation are spread throughout the study period, and with each doctor having a first control period without the use of tests (n = 10 patients) followed by a second period with the use of tests (n = 10 patients). Antibiotic prescriptions will be collected for each patient included during the two periods.

Each investigator will begin the study (on the randomly selected date) by including 10 patients who meet the eligibility criteria during the period without testing (first period), then the investigating physician will move on to the second period and use the TROD for 10 other patients.

The main objective is to evaluate the impact of using triplex rapid diagnostic tests (SARS-CoV-2/influenza/RSV) on antibiotic prescribing in the general population in community settings during the autumn-winter season of 2025-2026.

The secondary objectives are to : 1. Compare the probability of prescription during the initial consultation between the two study periods, 2. Compare the frequency of patient re-consultations within 15 days of inclusion between the two study periods, 3. Compare the proportions of patients with secondary hospitalisation within 15 days of inclusion between the two study periods, 4. Compare total antibiotic consumption within 15 days of inclusion between the two study periods, 5. Conduct a cost-consequence medical-economic study, 6. Assess the impact of these tests according to patient characteristics (age, medical history, initial symptoms, etc.) and prescribers (age, geographical area, practice modalities.), 7. Assess the proportions of SARS-CoV-2/influenza/RSV during the intervention period in patients presenting with all of the described symptoms of respiratory infection, 8. Estimate the sensitivity and specificity of the TROD in identifying different viruses using respiratory multiplex PCR, as well as the frequency and nature of other respiratory viral infections, 9. Describe the epidemiology of other respiratory viral infections, whether or not associated with SARS-CoV-2/influenza/RSV infections.

Inclusion criteria

• Age ≥ 1 year
• Presenting with:

• Either fever (temperature > 38°C measured by patient or physician) within the past 72 hours, and one of the following symptom combinations:

• Rhinorrhea (white, yellow, or green discharge) and/or nasal obstruction, and cough
• Body aches, cough, and fatigue
• Odynophagia and negative strepto-test
• Cough
• Otalgia
• Or suspicion of lower respiratory tract infection: signs of infection (respiratory rate > 20/min, heart rate > 100/min, fatigue, Body aches, chills, or fever), associated with pulmonary localization signs [cough, sputum, chest pain, auscultatory abnormality (rhonchi, crackles, or wheezing)]
• Affiliation with the national health insurance system
• Informed consent obtained from the adult participant, or from the person(s) with parental authority for a minor participant

Exclusion criteria

• Requirement for hospitalization
• Presence of a non-respiratory infection requiring concomitant antibiotic treatment.
• Patients covered by State Medical Aid (AME)