Resolving a Diagnostic Challenge: First PCR-Based Detection of Legionella longbeachae in Italy

Resolving a Diagnostic Challenge: First PCR-Based Detection of Legionella longbeachae in Italy

Key Points:

• This article reports the first PCR-based detection of Legionella longbeachae in Italy, using both the ImmuView Urinary Antigen Test and a multiplex PCR assay:
• The article emphasizes the importance of dual antigen testing for accurate identification and management of Legionella infections beyond L. pneumophila.

How to use this article? This article demonstrates that ImmuView enables rapid and accurate identification of L. longbeachae infections, which are often missed by standard tests. The study also highlights the importance molecular diagnostics and dual antigen testing for Legionella species, especially in patients with negative standard tests and no typical exposure history. This is the first reported case in Italy of Legionella longbeachae pneumonia confirmed by both PCR and ImmuView urinary antigen testing. The patient tested negative for Legionella pneumophila by standard urinary antigen tests, but positive for L. longbeachae using ImmuView and PCR, this highlights the risk of missed diagnosis with conventional methods. Treatment with intravenous levofloxacin led to rapid clinical improvement, supporting fluoroquinolones as first-line therapy for L. longbeachae pneumonia. The dual detection capability is especially important because L. longbeachae is frequently underdiagnosed and may present with atypical symptoms. Not just full focus on Legionella pneumophila; ImmuView also enables detection of Legionella longbeachae, even when standard tests and exposure history do not point to it, as demonstrated in this first Italian case.