Antibiotic resistance has been identified by the WHO as one of the biggest threats to the health of the world population. In Denmark, there has been an increasing focus on optimizing antibiotic consumption in recent years, but despite significant efforts, total consumption has increased in the hospital sector, especially regarding consumption and in the use of broad-spectrum antibiotics. Currently, a pneumonia diagnosis is primarily based on clinical symptoms such as cough, shortness of breath, chest pain, fever and sputum production, combined with X-ray of the lungs, relevant blood tests and microbiological analysis of sputum samples. X-ray is however an imprecise diagnostic tool, and sputum assays responses are available after 2 days. Sputum can be cultivated to determine the bacterial agent. However, the sputum samples are often of poor quality and many patients cannot deliver a sample. A recently published Danish study shows, that only half of the patients at the ED have sputum samples collected for culturing and none of them had the antibiotic treatment adjusted based on the microbiological results of the sputum.

This study's hypothesis is that point-of-care-polymerase chain reaction (POC-PCR) is superior to standard care on the prescription of targeted pneumonia treatment.

The diagnosis of pneumonia is challenged by nonspecific symptoms, uncertain diagnostic methods, poor prognostic tools and waiting time for test results up to several days. A patient's length of stay in a Danish Emergency Department rarely exceeds 48 hours. Within this period the patient is examined, treated and discharged either home or to another department. Therefore, rapid molecular detection of respiratory pathogens is needed to add value to the management of the diagnostics of pneumonia and could reduce the initial use of antibiotics. Molecular diagnostic tests based on polymerase chain reaction (PCR) assays generate high sensitive analyses in one hour from specimen collection. The Biofire® FilmArray® Pneumonia Panel plus (Biomérieux) can identify 18 bacterial agents including 3 atypical pathogens 9 viruses and 7 antimicrobial resistance genes. This point-of-care (POC) test is promising, as bacterial pathogens often coexist with viruses or are identified with mixed infections. However, the high specificity of molecular diagnostics can challenge the interpretation of clinically significant agents and demands interpretation by highly qualified specialists. Therefore, the POC-PCR combined with advice from a microbiologist has the potential to optimize therapeutic regimens and reduce prescriptions of inappropriate broad-spectrum antibiotics in the initial management of pneumonia.

This study aims to

• investigate how effective the addition of POC-PCR analysis of sputum is to the diagnostic set-up for community-acquired pneumonia on antibiotic prescription at 4 hours after admission without consequent adverse advents
• to identify the effect of POC-PCR on prescribed antibiotic treatment 48 hours after admission and 24 hours after discharge
• to investigate the agreement between POC-PCR and sputum culture on microbiological analysis

Inclusion Criteria:

• Emergency department patients suspected of pneumonia by the attending physician and with at least one of the following symptoms: dyspnea, cough, expectoration, chest tightness or fever and indication for chest x-ray

Exclusion Criteria:

• If the attending physician considers that participation will delay a life-saving treatment or patient needs direct transfer to the intensive care unit.
• Admission within the last 14 days
• Verified COVID-19 disease within 14 days before admission
• Pregnant women
• Severe immunodeficiencies: Primary immunodeficiencies and secondary immunodeficiencies (HIV positive CD4 <200, Patients receiving immunosuppressive treatment (ATC L04A), Corticosteroid treatment (>20 mg/day prednisone or equivalent for >14 days within the last 30 days), Chemotherapy within 30 days)

The patients will be blinded, and the investigator will be blinded to POC-PCR results, data management and analysis, but not allocation. Outcome assessors will not be blinded