Related Experiment Video
Updated: Oct 19, 2025

Use of Galleria mellonella as a Model Organism to Study Legionella pneumophila Infection
Published on: November 22, 2013
Legionella Coinfection in a Patient With COVID-19 Pneumonia
Yogesh Subedi1,2,3, Christopher J Haas1,2,3,4
1Medicine, MedStar Union Memorial Hospital, Baltimore, USA.
Abstract:
Bacterial superinfection is a well-reported complication of viral pneumonia leading to significantly increased morbidity and mortality. Such superinfections have been reported in patients with pathogenic coronaviruses including severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS), but there are scant reports pertaining to superinfection in the context of coronavirus disease 2019 (COVID-19). We report a case of a middle-aged man who presented with worsening shortness of breath in the context of COVID-19 complicated by superimposed Legionella pneumophilia pneumonia. This case serves to highlight the possibility of bacterial superinfections and to be aware of such possibilities when patients are not responding to standard courses of treatment for COVID-19 as quick clinical deterioration is likely to develop.
Insights
Bacterial superinfection is a serious complication of viral pneumonia. This case highlights a patient with coronavirus disease 2019 (COVID-19) who developed a superimposed Legionella bacterial pneumonia.
Area of Science:
- Infectious Diseases
- Pulmonology
- Critical Care Medicine
Background:
- Bacterial superinfection is a known complication of viral pneumonia, increasing patient morbidity and mortality.
- While reported with SARS and MERS, bacterial superinfections in coronavirus disease 2019 (COVID-19) are less documented.
- Prompt recognition and treatment of superinfections are crucial for patient outcomes.
Observation:
- A middle-aged male patient presented with worsening dyspnea.
- The patient had a confirmed diagnosis of coronavirus disease 2019 (COVID-19).
- Clinical deterioration suggested a superimposed bacterial pneumonia.
Findings:
- The patient was diagnosed with a secondary pneumonia caused by Legionella pneumophila.
- This case represents a documented instance of bacterial superinfection in a COVID-19 patient.
- Legionella pneumophila superinfection led to significant clinical decline.
Implications:
- Clinicians should consider bacterial superinfections in COVID-19 patients who do not respond to standard treatment.
- Early recognition and appropriate antibiotic therapy for bacterial superinfections are vital.
- Awareness of potential superinfections can prevent rapid clinical deterioration in COVID-19 patients.
Related Concept Videos
Pneumonia III: Complications and Assessment
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia II: Pathophysiology
Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed....
Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...

