Legionellosis in Japan: A Self-inflicted Wound?

Successful Outpatient Treatment of Legionella pneumophila Pneumonia With Lascufloxacin: A Case Report

Legionella pneumophila is a significant cause of community-acquired pneumonia (CAP) and often necessitates hospitalization. Lascufloxacin (LSFX), a novel fluoroquinolone with high pulmonary penetration, has demonstrated efficacy in treating Legionella pneumonia in hospitalized patients. However, its use in an outpatient setting for Legionella pneumonia has not been previously documented, despite its favorable pharmacokinetics and safety profile. We present a 49-year-old man with a history of smoking and dyslipidemia who developed a high fever, headache, and malaise. In addition to the presence of relative bradycardia, chest imaging revealed right lower lobe pneumonia, and a urinary antigen test confirmed Legionella pneumophila infection. Despite this diagnosis, his condition remained stable (A-DROP score: 1), allowing for outpatient management. He was prescribed LSFX 75 mg/day for 10 days, with close monitoring via home pulse oximetry and scheduled frequent follow-up visits. His fever was resolved by day 3, and he fully recovered without complications or adverse effects. This is the first reported case of successful outpatient treatment of Legionella pneumonia with LSFX. The decision for outpatient therapy was based on the patient's stable condition based on A-DROP (age, dehydration, respiratory failure, orientation disturbance, and low blood pressure) scoring, LSFX's excellent bioavailability and pulmonary penetration, and its lack of renal dose adjustment requirements. However, the A-DROP scoring system may underestimate Legionella pneumonia severity, necessitating careful patient selection. LSFX appears to be a safe and effective option for outpatient management of mild Legionella pneumonia. This case highlights its potential as an alternative to inpatient treatment, but further studies are required to confirm its broader applicability.

The Adequacy of Current Legionnaires' Disease Diagnostic Practices in Capturing the Epidemiology of Clinically Relevant Legionella: A Scoping Review

Legionella is an underdiagnosed and underreported etiology of pneumonia. Legionella pneumophila serogroup 1 (LpSG1) is thought to be the most common pathogenic subgroup. This assumption is based on the frequent use of a urinary antigen test (UAT), only capable of diagnosing LpSG1. We aimed to explore the frequency of Legionella infections in individuals diagnosed with pneumonia and the performance of diagnostic methods for detecting Legionella infections. We conducted a scoping review to answer the following questions: (1) "Does nucleic acid testing (NAT) increase the detection of non-pneumophila serogroup 1 Legionella compared to non-NAT?"; and (2) "Does being immunocompromised increase the frequency of pneumonia caused by non-pneumophila serogroup 1 Legionella compared to non-immunocompromised individuals with Legionnaires' disease (LD)?". Articles reporting various diagnostic methods (both NAT and non-NAT) for pneumonia were extracted from several databases. Of the 3449 articles obtained, 31 were included in our review. The most common species were found to be L. pneumophila, L. longbeachae, and unidentified Legionella species appearing in 1.4%, 0.9%, and 0.6% of pneumonia cases. Nearly 50% of cases were caused by unspecified species or serogroups not detected by the standard UAT. NAT-based techniques were more likely to detect Legionella than non-NAT-based techniques. The identification and detection of Legionella and serogroups other than serogroup 1 is hampered by a lack of application of broader pan-Legionella or pan-serogroup diagnostics.

Legionella pneumophila-Virulence Factors and the Possibility of Infection in Dental Practice

Legionella pneumophila is defined as a bacterium that can cause severe pneumonia. It is found in the natural environment and in water, and is often found in water tanks. It can be an integral part of biofilms in nature, and the protozoa in which it can live provide it with food and protect it from harmful influences; therefore, it has the ability to move into a sustainable but uncultured state (VBNC). L. pneumophila has been shown to cause infections in dental practices. The most common transmission route is aerosol generated in dental office water systems, which can negatively affect patients and healthcare professionals. The most common way of becoming infected with L. pneumophila in a dental office is through water from dental instruments, and the dental unit. In addition to these bacteria, patients and the dental team may be exposed to other harmful bacteria and viruses. Therefore, it is vital that the dental team regularly maintains and decontaminates the dental unit, and sterilizes all accessories that come with it. In addition, regular water control in dental offices is necessary.