This is a Prospective, multi-center study enrolling adults subjects presented to the ED/Urgent care, with symptoms consistent with lower respiratory infection (LRTI).

The reason of this study is to demonstrate the MeMed BV can help clinicians make decisions about using antibiotics in patients with lower respiratory track infections and see how it would impact clinical outcomes, antibiotics use, hospitalizations, ED clinicians find ways to improve health and medical care.

There will be a pre-study implementation phase (JUNO trial), in which approximately 250 patients will be recruited. Data obtained for these patients will not be included in the analysis. The purpose of the pre-study implementation phase is to enable the participating clinicians to become familiar with the MeMed BV test. An additional purpose is to test the design and operational assumptions before the subsequent JUPITER trial.

INCLUSION CRITERIA

• Patients eligible for inclusion are required to fulfill all of the following criteria:
• Written informed consent must be obtained from the patient or his/her legal guardian.
• 18 years of age or older.
• Current disease duration ≤ 7 days.
• Tactile fever or measured temperature ≥ 37.8°C (100°F) (any body site, any measurement device, including self-reported), either of them noted at least once within the last 7 days.
• Clinical suspicion of bacterial or viral LRTI: At least one of the following respiratory signs or symptoms: cough (new or worsening), sputum production, dyspnea/shortness of breath, auscultatory abnormality (e.g. wheezing, rhonchi).
• Clinician intent to prescribe antibiotics based on the currently available data.

EXCLUSION CRITERIA

Patients fulfilling any of the following criteria are not eligible for inclusion in the infectious cohort:

• Systemic antibiotics within 72 hours prior to enrollment
• Inflammatory disease (e.g., IBD, SLE, Rheumatoid arthritis, Kawasaki, other vasculitis)
• Congenital immune deficiency (CID)
• A proven or suspected infection on presentation with Mycobacterial (e.g., MAC, MABC), parasitic or fungal (e.g., Candida, Histoplasma, Aspergillus) pathogen
• HIV, HBV, or HCV infection (self-declared or known from medical records)
• Major surgery, trauma and\or burns in the last 7 days
• Pregnancy- self reported or medically confirmed
• Active malignancy - Cancer diagnosed within the previous six months, recurrent, regionally advanced or metastatic cancer, cancer for which treatment had been administered within six months, or hematological cancer that is not in complete remission.
• Patients with severe illnesses that affect life expectancy and quality of life such as end stage renal disease, end stage liver disease or severe COPD.
• Clinician intent to hospitalize patient.
• Patients with suspected concomitant infections (e.g. UTI, cellulitis, gastroenteritis, etc.)
• Active treatment with immune-suppressive or immune-modulating therapies, including without limitations:

Administration of PO\IV\IM high dose steroids >1mg/kg/day prednisone (or equivalent) at some point in the past 10 days or daily continuous use of steroids > 0.25 mg/kg/day in the past 7 days Monoclonal antibodies, anti-TNF agents Intravenous immunoglobulin (IVIG) Cyclosporine, Cyclophosphamide, Tacrolimus, Azathioprine, Methotrexate G/GM-CSF, Interferons

•Considered unsuitable for the study by the study team

applicable only for control arm