Secondary infections

A secondary infection is an infection that occurs during or after treatment for another infection. It may be caused by the first treatment or by changes in the body or immune system that allow a second infection.

Two examples of a secondary infection are:

  • A vaginal yeast infection after taking antibiotics to treat an infection caused by bacteria
  • Pneumonia caused by bacteria or fungi after having an upper respiratory infection (like a cold) that was caused by a virus
Secondary infection

Secondary infection occurs during or after treatment of a primary infection because the normal bacterial flora is destroyed, allowing yeast to flourish.

Immune system structures

The immune system protects the body from potentially harmful substances. The inflammatory response (inflammation) is part of innate immunity. It occurs when tissues are injured by bacteria, trauma, toxins, heat or any other cause.