The fast increase of Multidrug-resistant microorganisms (MDRO) due to the high amount of antimicrobials being poorly used may be limited by better regulating antimicrobial usage globally. The goal of this observational study is the performance of the MeMed BV® test in the MeMed Key® device at the emergency department to a) support the differential diagnosis between bacterial and viral infections of the respiratory tract and b) provide evidence of how the use of this test may limit gut colonization by MDRO.

Antimicrobial resistance is one of the major threats to the society. One major driver of this phenomenon is the extensive use of antibiotics particularly during the winter months as empirical use for respiratory tract infections. Most of these infections, namely acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and acute bronchitis, are of viral origin and no antibiotics need to be prescribed. To limit the ambiguity of prescribing physicians leading them to unnecessary prescription of antibiotics, one new point-of-care test has been developed which may assist to distinguish between bacterial and viral infections.

This test is called MeMed BV® and is providing the integrative information of three measurable parameters in blood, namely TRAIL (tumour necrosis factor-related apoptosis-inducing ligand), IP-10 (interferon-gamma-induced protein-10) and CRP (C-reactive protein). TRAIL and CRP are increased in the case of bacterial infection; IP-10 is increased in viral infections; and the integrative algorithm suggests the likelihood for a patient to present with bacterial infection, with viral infection or to be at an intermediate state. Based on the results of the Appolo clinical study, the use of the MeMed BV® test which runs in the MeMed Key® device have been registered by the European Medicines Agency and by the Food and Drug Administration (FDA) of the United States for use in the Emergency department (ED) of differentiate between bacterial and viral infections.

The present study is aiming to the performance of the MeMed BV® test in the MeMed Key® device at the ED to a) support the differential diagnosis between bacterial and viral infections of the respiratory tract and b) provide evidence of how the use of this test may limit gut colonization by MDRO.

Inclusion Criteria:

• Age 18 years or more
• Both genders
• Written informed consent provided by participants or their legal representatives
• Symptoms compatible with the diagnosis of respiratory tract infection defined as at least one of: fever (core temperature more than or equal to 37.50C), chills, sore throat, myalgias, sudden onset of headache, running nose
• Onset of symptoms the last 7 days

Exclusion Criteria:

• Fever (core temperature more than or equal to 37.50C) for more than 7 days
• Neutropenia defined as less than 1,000 neutrophils/mm3
• Intake of chemotherapy for any malignancy
• Intake of radiotherapy for any malignancy
• Medical history of known active infection by the human immunodeficiency virus (HIV) or hepatitis B virus (HBV) or hepatitis C virus (HCV)
• Pregnancy or lactation
• Any acute trauma
• Any operation the last 7 days
• Presence of acute burns

Screening will be done for the inclusion and exclusion criteria in all patients admitted in the participating sites. Participants will be patients meeting all inclusion criteria and none of the exclusion criteria.