UK guideline provides recommendations for differentiating viral COVID-19 pneumonia from bacterial pneumonia
The National Institute for Health and Care Excellence (NICE) in the UK has published guidance on the management of suspected or confirmed pneumonia in the community during the COVID-19 pandemic.
The guideline provides recommendations for differentiating between a COVID-19 and bacterial cause for community-acquired pneumonia. It recognises that:
Signs and symptoms of viral pneumonia caused by COVID-19 and pneumonia caused by bacteria are similar, making it difficult to differentiate between the conditions clinically
With COVID-19 becoming more prevalent in the community, patients presenting with pneumonia symptoms are more likely to have a COVID-19 viral pneumonia than a community-acquired bacterial pneumonia.
COVID-19 viral pneumonia may be more likely if the patient presents with:
A history of typical COVID-19 symptoms for about a week
Absence of pleuritic pain.
A bacterial cause of pneumonia may be more likely if the patient:
Becomes rapidly unwell after only a few days of symptoms
No history of typical COVID‑19 symptoms.
This topic covers pneumonia caused by COVID-19 as a differential diagnosis only. For more detail on the diagnosis and management of community-acquired pneumonia caused by COVID-19, see our topic Coronavirus disease 2019 (COVID-19) external link opens in a new window.
Original source of updateexternal link opens in a new window
Patients with community-acquired pneumonia (CAP) typically present with symptoms and signs consistent with a lower respiratory tract infection (i.e., cough, dyspnoea, pleuritic chest pain, mucopurulent sputum, myalgia, fever) and no other explanation for the illness. Older people present more frequently with confusion or worsening of pre-existing conditions, and without chest signs or fever.
Diagnostic confirmation in all patients presenting to hospital requires evidence of consolidation (new shadowing that is not due to any other cause) on chest x-ray. A chest x-ray should not be requested routinely for patients managed in the community.
The CURB-65 mortality risk score (hospital setting) or CRB-65 severity score (community setting) are the basis, together with clinical judgement, for deciding whether to manage the patient in hospital or at home and determining appropriate therapy.
Initial treatment is with empirical antibiotics, following national/international guidelines and local epidemiology. In hospital, antibiotics should be administered within 4 hours of presentation.
Sputum and blood samples should be sent for culture in people with moderate- or high-severity CAP, ideally before antibiotics are started, and legionella and pneumococcal urine antigen testing should be considered.
Patients with oxygen saturation <94% (or <88% in patients at risk of CO2 retention) should receive supplemental oxygen.
Sepsis should be considered whenever an acutely unwell person presents with likely infection, even if their temperature is normal. Local protocols (e.g., Sepsis Six or Surviving Sepsis Campaign 1 hour care bundle) should be followed for investigation and treatment of all patients with suspected sepsis, or those at risk, within 1 hour.
Community-acquired pneumonia (CAP) is defined as pneumonia acquired outside hospital or healthcare facilities. Clinical diagnosis is based on a group of signs and symptoms related to lower respiratory tract infection with presence of fever >38ºC (>100ºF), cough, mucopurulent sputum, pleuritic chest pain, dyspnoea, and new focal chest signs on examination such as crackles or bronchial breathing. Older patients present more frequently with confusion or worsening of pre-existing conditions, and without chest signs or fever. This topic focuses on the diagnosis and management of CAP in adults.
History and exam
- blood culture
- sputum culture (± Gram stain)
- urinary antigen testing for legionella and pneumococcus
- polymerase chain reaction (PCR) and/or serological tests
- CT scan of chest
- chest ultrasound
- thoracocentesis and pleural fluid culture
- computer tomographic pulmonary angiography (CTPA)
Honorary Professor of Respiratory Sciences
University of Leicester
JB is Chair of the British Thoracic Society.
JB declares that he has no competing interests.
BMJ Best Practice would like to gratefully acknowledge the previous team of expert contributors, whose work has been retained in parts of the content:
Catia Cilloniz MSc, PhD
Hospital Clinic of Barcelona
Antoni Torres MD, PhD
Professor of Medicine
Pulmonary Intensive Care Unit
Hospital Clinic of Barcelona
CC and AT are each authors of a number of references cited in this topic.
Consultant Respiratory Physician and Honorary Professor of Medicine
Nottingham University Hospitals NHS Trust
WSL was chairman of the British Thoracic Society community-acquired pneumonia guidelines committee and a member of the guideline development group for the National Institute for Health and Care Excellence pneumonia guidelines. His institution has received unrestricted investigator-initiated research funding from Pfizer for a multicentre study of pneumococcal pneumonia in which he was the chief investigator, and research funding from the National Institute for Health Research for studies in pneumonia in which he was the principal investigator. He is also an author of at least one reference cited in the topic.
Section Editor, BMJ Best Practice
HDC declares that she has no competing interests.
Lead Section Editor, BMJ Best Practice
RW declares that she has no competing interests.
Comorbidities Editor, BMJ Best Practice
JC declares that she has no competing interests.
Drug Editor, BMJ Best Practice
AM declares that he has no competing interests.
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