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Case Reports
. 2024 Nov 19;16(11):e74035.
doi: 10.7759/cureus.74035. eCollection 2024 Nov.

Legionella Pneumonia Undetected by Repeated Urinary Antigen Testing With Ribotest® Legionella

Yasushi Murakami  1 , Mika Morosawa  1 , Yasuhiro Nozaki  1 , Yoshio Takesue  2
Affiliations
Case Reports

Legionella Pneumonia Undetected by Repeated Urinary Antigen Testing With Ribotest® Legionella

Yasushi Murakami et al. Cureus. .

Abstract

This report presents a patient with Legionella pneumonia (LP), initially presented with fever and mild hypoxemia, with subsequent progression to severe pneumonia during hospitalization. Despite multiple negative urinary antigen tests using Ribotest® Legionella, the diagnosis was confirmed via the loop-mediated isothermal amplification method of lower respiratory tract secretions. This case highlights the diagnostic limitations of Ribotest® Legionella and emphasizes the importance of a comprehensive diagnostic strategy, incorporating nucleic acid amplification tests or culture in suspected patients with LP. Early recognition of these diagnostic challenges is critical for optimizing patient outcomes.

Keywords: bronchoscopy; legionella pneumonia; loop-mediated isothermal amplification; ribotest® legionella; urinary antigen test.

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Conflict of interest statement

Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Chest X-ray findings during hospitalization
(A, B, C) Chest X-ray on day 0 (admission), day 2, and day 6, respectively. (A) Wedge-shaped infiltration in the left lower lobe adjacent to the pleura (arrow), along with GGOs in the left upper lobe (arrowhead). (B) The consolidation and GGOs expand to involve the entire left lung. (C) Collapse of the left lower lobe and extension of GGOs into the right lung (arrow). GGOs, ground-glass opacities
Figure 2
Figure 2. Chest CT during hospitalization
(A, B) Chest CT on day 0 (admission) and day 5, respectively. (A) Wedge-shaped consolidation with an air bronchogram in the left lower lobe adjacent to the pleura (arrow), along with scattered GGOs in the left upper lobe (arrowheads). (B) Complete collapse of the left lower lobe, with a small pleural effusion (arrow). A new infiltrate is observed in the left upper lobe, and GGOs have extended into the right upper lobe. GGOs, ground-glass opacities
Figure 3
Figure 3. Clinical course during hospitalization
Day 0 represents the day of admission. BS, bronchoscopy; FiO2, fraction of inspired oxygen; LDH, lactate dehydrogenase; SpO2, pulse oximetry saturation; UAT, urinary antigen test
See this image and copyright information in PMC

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