When should I consider referring a patient with suspected Legionnaires' disease to secondary care?

Consider referring a patient with suspected Legionnaires' disease to secondary care if they present with features of severe community-acquired pneumonia, such as a CRB-65 score of 2 or more, or if clinical judgement indicates a more serious illness like sepsis or cardiorespiratory failure.

Specifically, urgent hospital admission is recommended for patients with a CRB-65 score of 3 or more, and hospital assessment should be considered for those with a score of 1 or 2, especially if symptoms are not improving with antibiotics or if the patient is unable to take oral medication.

Additional factors influencing referral include low oxygen saturation (<90% on room air), respiratory rate ≥30 breaths per minute, systolic blood pressure ≤90 mmHg, confusion or abnormal mental status, inability to eat without assistance, and presence of significant comorbidities or frailty.

Use clinical judgement alongside the CRB-65 score, considering the patient's wishes, social support, pregnancy status, and pulse oximetry results to decide on referral urgency.

Since Legionnaires' disease is a form of community-acquired pneumonia often requiring hospital management, these criteria apply to suspected cases.

Also, if microbiological testing has been done and results suggest bacterial resistance or if the patient is not responding to initial treatment, referral or specialist advice should be sought.