Legionella Infection and Vascular Complications: A Systemic Threat Beyond Pneumonia
Legionnaires’ disease, caused by the intracellular gram-negative bacterium Legionella pneumophila , is primarily known as a severe form of atypical pneumonia. However, in many cases—especially in older adults, immunocompromised patients, or those with pre-existing vascular disease— Legionella infection can lead to life-threatening vascular and cardiac complications . These are driven by direct bacterial invasion, an exaggerated immune response (sepsis), and profound systemic inflammation. Image reference: https://www.mdpi.com/2075-4418/13/2/280 Severe Legionella pneumophila pneumonia in a patient with iron overload Legionella bacteria thrive on iron, so iron overload (hemochromatosis) significantly increases the risk and severity of Legionnaires' disease, allowing the bacteria to replicate more easily outside immune cells by overcoming iron-withholding defenses. High ferritin levels, a marker of iron storage, are common in Legionella infections, acting both as a sig...