Secondary infections

Definition

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 immune system.

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 after having an upper respiratory infection (like a cold) that was caused by a virus

Images

Secondary infection
Immune system structures

References

Dockrell DH, Sundar S, Angus SBJ, Hobson RP. Infectious disease. In: Walker BR, Colledge NR, Ralston SH, Penman ID, eds. Davidson's Principles and Practice of Medicine. 22nd ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014:chap 13.

Reid PT, Innes JA. Respiratory disease. In: Walker BR, Colledge NR, Ralston SH, Penman ID, eds. Davidson's Principles and Practice of Medicine. 22nd ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014:chap 19.

Review Date: 
9/27/2017
Reviewed By: 
Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.