Imaging findings in pathogenic synergistic co-infection between influenza A virus and Streptococcus pyogenes

Streptococcus pyogenes is a bacterium that causes a wide range of diseases, from pharyngitis to severe infections such as pneumonia and toxic shock syndrome. Globally, it affects millions of people, and in Chile cases have increased since 2023, mainly affecting children and the elderly. Coinfection with influenza A worsens the disease, as the virus damages the respiratory epithelium, facilitating bacterial invasion and increasing the risk of serious complications such as necrosis and septic shock. This study analyzes four cases of patients with severe respiratory failure due to coinfection with influenza A and S. pyogenes, all of whom presented with severe pneumonia and empyema, requiring invasive procedures. Computed tomography scans showed multifocal consolidations and cavitary necrosis. The study highlights the importance of influenza Avaccination, active surveillance of S. pyogenes infections, and the appropriate use of antibiotics to prevent complications andreduce mortality.