Inclusion Criteria:
Patients:
Age 18 years or above;
Presentation at the emergency department (ED);
Working diagnosis of CAP at the ED with the presence of at least two of the following criteria:
- New or worsened coughing;
- Production of purulent sputum or change in sputum colour;
- Temperature >38.0 ⁰C or ≤36.0 ⁰C (tympanic);
- Auscultatory findings consistent with pneumonia, including rales, evidence of pulmonary consolidation (dullness on percussion, bronchial breath sounds, rales, or egophony), or both;
- White blood cell count of >10x10^9 cells/L or <4x10^9 cells/L or >15% bands;
- C-reactive protein level ≥30mg/L;
- Dyspnea, tachypnea, (>20 breaths per minute), or hypoxemia (arterial pO2 <60mmHg or peripheral O2 saturation <90%).
New consolidation(s) on the chest radiograph or computed tomography (CT);
No other explanation for the signs and symptoms;
Control group 1 - Related controls
- Being aged 18 years or above;
- Close relative of the patient: relative defined as living in the same house as the CAP patient or daily contact;
- Is at the hospital at the moment of inclusion of the CAP patient or is willing to come for testing within 7 days;
Control group 2 - Unrelated healthy individuals
- Being aged 18 years or above;
- Subject with a preoperative appointment with the anaesthiologist for a planned surgical procedure;
- Age matched to a included CAP patient (+-10 years);
- Time matched to a included CAP patient (up to 14 days after inclusion of the CAP patient);
- Gender matched to a included CAP patient.
Control group 3 - Patients with stable COPD
- Being aged 18 years or above;
- Diagnosis of COPD confirmed with spirometry (GOLD criteria 2017)(76);
- Stable disease.
Control group 4 - Patients with exacerbation of COPD
- Being aged 18 years or above;
- Diagnosis of COPD confirmed with spirometry (GOLD criteria 2017)(76);
- Diagnosis of exacerbation of COPD: defined as an acute event characterised by a worsening of the patient's respiratory symptoms that is beyond normal day-to-day variations and leads to a change in medication (76).
- Presentation at emergency department with the suspicion of an exacerbation.
Exclusion Criteria:
In general:
- Recent pneumonia (< 1 month) or pneumonia in last 3 months with known pneumococcal aetiology with one of current diagnostics;
- Was included in the study group before;
- Not capable of understanding information needed to sign informed consent.
Patients:
- Aspiration pneumonia;
- Hospitalisation for two or more days in the last 14 days;
- History of cystic fibrosis.
For all control groups:
- Fits inclusion criteria for patient group;
- Present or recent hospitalisation (14 days);
- Fits inclusion criteria for patient group;
- Use of antibiotics in the last 14 days, including maintenance antibiotic therapy.
Control group 1 and 2 - Related healthy controls and unrelated healthy individuals
- Active infectious respiratory complaints defined as defined as two or more respiratory symptoms (cough, nasal congestion, runny nose, sore throat or sneezes);
- Temperature >38.0 ⁰C;
- Fits inclusion criteria for control group 3 or 4;
- Chronic pulmonary disease: COPD, asthma, cystic fibrosis, bronchiectasis.
Control group 3 - Patients with stable COPD
- Temperature >38.0 ⁰C;
- Stable disease;
- Fits inclusion criteria for control group 4;
- Recent exacerbation (<1 month) defined as increased respiratory symptoms with need of antibiotic and/or corticosteroid therapy;
- History of cystic fibrosis.
Control group 4 - Patients with exacerbation of COPD
- Current pneumonia;
- Recent exacerbation (<1 month) defined as increased respiratory symptoms with need of antibiotic and/or corticosteroid therapy;
- Fits inclusion criteria for control group 3;
- History of cystic fibrosis.