Breaking ground: a rare case of Legionella longbeachae in a gardener

P3998 | 02964
Breaking ground: a rare case of Legionella longbeachae in a gardener
J. Griffiths, A. Ainarozidou, K. Bamford, G. Vanstone, D. Cain, T. De Beer
Royal Cornwall Hospital NHS Trust – Truro (United Kingdom)

Background

Legionella longbeachae, a rare cause of Legionnaires’ disease in the UK, is more commonly reported in Australasia and sporadically in Europe. The pathogen is strongly associated with exposure to potting mixes and compost. Between 2017 and 2023, only 35 cases of L. longbeachae were reported in England and Wales (1.1% of Legionella cases), with a case fatality rate of 28.6%, significantly higher than L. pneumophila (5.8%). We report the case of a healthy 51-year-old male presenting with severe community-acquired pneumonia (CAP) caused by L. longbeachae, highlighting the diagnostic and management challenges in a low-prevalence setting. Four additional cases have recently been identified in Truro, further emphasising the importance of heightened awareness of this pathogen.

Case(s) description

A 51-year-old non-smoking landscape gardener presented with a 7-day history of fever, worsening shortness of breath, and productive cough with orangey-red sputum. Initial evaluation in the emergency department showed hypoxia (SpO₂ 87%), tachypnoea (RR 26), fever (39°C), and lobar pneumonia on chest X-ray. Despite initial treatment with intravenous tazocin and oral doxycycline, the patient developed worsening respiratory failure and fast atrial fibrillation, requiring intensive care admission and high-flow nasal oxygen (HFNO). Diagnostic testing identified Legionella longbeachae in sputum by multiplex tandem PCR (MT-PCR); this was later confirmed by culture on Legionella BMPA agar. Management was switched to a 10-day course of oral levofloxacin. The patient gradually improved, with complete resolution of pneumonia on follow-up imaging. This case underscores the importance of considering L. longbeachae in CAP among patients with occupational or environmental exposures, even in low-prevalence regions.

Discussion

This case highlights the diagnostic challenges atypical CAP poses, especially due to rare pathogens like L. longbeachae. It emphasizes the limitations of urinary antigen testing, which does not detect L. longbeachae and molecular diagnostics’ value in guiding targeted therapy. Awareness of L. longbeachae among clinicians is critical, particularly in patients with relevant environmental exposures, as timely recognition and targeted therapy with fluoroquinolones can be lifesaving. The association between L. longbeachae and potting mixes suggests an occupational exposure risk in gardeners, warranting public health awareness.

Outputs

https://registration.escmid.org/AbstractList.aspx?e=30&header=0&preview=1&aig=-1&ai=30914

Talk details
13b. Bacterial infections
Poster Session
13. Case reports and case series (n less than 10)
Breaking ground: a rare case of Legionella longbeachae in a gardener (P3998)
J. GRIFFITHS
15/04/2025 12:00 – 13:30 CEST
Sector / Row / Position: B / 3 / 35