INFLUENZA

Subject: Science & tech

Context: Researchers at Sweden’s Karolinska Institutet have described findings leading to so-called “superinfections”. It can also contribute to research on Covid-19.

Concept:

• The researchers found that different nutrients and antioxidants, such as vitamin C, leak from the blood. This creates an environment in the lungs that favours growth of the bacteria.
• The bacteria adapt to the inflammatory environment by increasing the production of an enzyme called HtrA. The presence of HtrA weakens the immune system and promotes bacterial growth in the influenza-infected airways.

Influenza:

• Influenza is caused by a virus, but the most common cause of death is secondary bacterial pneumonia rather than the influenza virus per se.
• Pneumococcal infections are the most common cause of community-acquired pneumonia and a leading global cause of death.
• A prior influenza virus infection sensitizes for pneumococcal infections, but mechanisms behind this increase susceptibility are not fully understood.
• Researchers at Karolinska Institutet have now identified influenza-induced changes in the lower airways that affect the growth of pneumococci in the lungs.