Fatal Legionnaires' disease coincident with initiation of immunosuppressive therapy

Area of Science:

• Infectious Diseases
• Medical Microbiology
• Clinical Immunology

Background:

• Legionnaires' disease is a severe pneumonia caused by Legionella bacteria.
• Erythromycin gluceptate is a parenteral antibiotic used for Legionnaires' disease.
• Chemotherapy often involves immunosuppressive agents, increasing infection risk.

Observation:

• A patient with Legionnaires' disease received 30 days of parenteral erythromycin gluceptate.
• Chemotherapy was initiated while the patient was still undergoing antibiotic treatment.
• Direct fluorescent antibody testing on sputum indicated persistent Legionella pneumophila infection.

Findings:

• The patient suffered a fatal relapse of Legionnaires' disease.
• Persistent Legionella infection was detected despite prolonged antibiotic therapy.
• The relapse coincided with the start of chemotherapy.

Implications:

• Immunosuppressive therapy, like chemotherapy, may exacerbate persistent Legionnaires' disease.
• Direct fluorescent antibody testing is crucial for monitoring Legionella infection activity.
• Delaying immunosuppressive agents until infection clearance is vital in specific patient cases.