The ACCREDIT study - Acute respiratory infections and chronic respiratory disease exacerbations characterisation and personalised treatment platform study 2 (AcCREDiT 2).

Patients with respiratory infections (such as pneumonia) or exacerbations of chronic respiratory conditions (such as emphysema) often require hospital admission. Infections or exacerbation are commonly caused by bacteria, viruses or fungi. In at least a quarter of patients no infectious cause of the exacerbation is found. Depending on the cause of the respiratory infections or exacerbations of chronic respiratory condition patients require prompt treatment with anti-infective drugs (antibiotics, anti-fungal or antiviral drugs) or anti-inflammatory drugs such as corticosteroids.

Patients with respiratory infection or exacerbations of chronic respiratory conditions develop symptoms such as cough, sometimes with sputum, fever or breathlessness. These symptoms can be similar across several conditions, many of which are not due to infection (for example heart failure or blood clots in the lungs). When assessing patients with respiratory symptoms, clinicians face the challenge of limited information in the early stages of care as it takes three days to identify infectious organisms in the laboratory. Even when an infection is strongly suspected, distinguishing bacterial from viral or fungal infections on clinical grounds alone is difficult. This uncertainty often leads clinicians to prescribe a number of treatments, including antibiotics, before a clear diagnosis is made. Timely treatment is crucial for success and improved patient outcomes, especially for critically ill patients admitted to the intensive care unit (ICU). However, antibiotics may cause side effects, such as sickness and diarrhoea, and overuse of antibiotics leads to antibiotic resistance, making antibiotics less effective when they are really needed. Giving antibiotics to patients with an infection or exacerbation and avoiding antibiotics in patients without an infection requires rapid diagnostic tests. Furthermore, giving antibiotics prior to taking samples to diagnose infection can affect the sample being tested making it more likely to not give a useful result. For a diagnostic test for infection to be most useful it needs to be collected before an antibiotic is given - this is true for both clinical tests and those research tests which are clinical tests in development.

Modern technologies allow testing for an infection in hours rather than days. In order to understand how effective these technologies are, samples need to be taken from patients before they start treatment. In routine NHS care samples to test for infection should be taken before treatment has been started. However, in research studies samples are often taken up to a day after treatment has started which affects how effective the test is at finding infection. The forerunner to this study, called AcCREDiT, proposed investigating very rapid ways of identifying individuals with respiratory infection and exacerbation. However, the study team encountered challenges during the informed consent process, particularly with acutely unwell patients. Therefore, the AcCREDiT-2 was designed in collaboration with patients and public contributors to look at the feasibility of a modified informed consent process: verbal consent, assent for individuals with capacity to consent for themselves, and deferred consent.

AcCREDiT-2 will be an observational study, meaning that no treatment will be changed, and no experimental drugs or tests used to influence the clinical care of participants. AcCREDiT-2 will also be a 'feasibility study', which is a smaller study designed to see what works well before embarking on a larger project. During the study the investigators will collect clinical information and samples, such as blood, sputum and stool, from patients who come to hospital with a presumed respiratory infection or exacerbation of their chronic respiratory condition. The investigators will compare new diagnostic tests to traditional laboratory tests to understand their relative advantages and disadvantages for patient care.

This is a 'feasibility' study, a small study ran first to make sure things work properly before expanding to a much larger study.

Inclusion Criteria:

• Age ≥ 18 years

• Clinically suspected acute respiratory infection or exacerbation of chronic respiratory disease

• Availability of respiratory tract sample

  1. Spontaneously breathing patients are able to produce a sputum sample
  2. Mechanically ventilated patients in intensive care are due to have an Bronchoalveolar lavage or non-directed bronchial lavage for a clinical indication

• Due to receive either:

  1. an anti-infective agent (e.g. antibiotic, antiviral or antifungal) OR
  2. a systemic anti-inflammatory agent (e.g. corticosteroid)

• Valid informed consent, assent or enrolment through deferred consent

• Re-enrolment will be allowed if presenting for a separate acute event

Exclusion Criteria:

• Alternate respiratory cause of presentation in the opinion of the treating physician (e.g. pulmonary embolism, heart failure, etc.)
• High clinical likelihood of infection with a Hazard Group 3 pathogen (e.g. tuberculosis, anthrax, plague)

In patients whose symptoms are consistent with an acute respiratory infection or exacerbation, but the prescription of an eligible agent has not yet been confirmed