Synonyms: Taint, Poison

Medical Specialties: Infectious disease, Internal medicine

Clinical Definition

Contamination is the presence of an unwanted or harmful agent, such as bacteria. Contamination may involve the body or inanimate objects (e.g., surgical instruments, bandages or dressings). Food and liquids can also become contaminated. In some instances, contamination may lead to an infection or illness.

In Our Own Words

Contamination is the introduction of an infectious or unwanted substance in an area where it should not be. In addition to the human body, food, water and objects may also become contaminated with material or substances, such as toxins, bacteria, viruses and mold.


Preventing contamination is important for several reasons. Contamination of laboratory samples, such as blood tests, can interfere with accurate results. Contamination of medical devices, such as surgical instruments, can lead to infection. Food and water contamination may cause disease and illness.

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  • Wound Care Information Network. “Infection vs Contamination/Colonization.” Accessed February 2014.
  • VanMeter K.,PhD, Hubert R., BS, VanMeter W., PhD. “Microbiology for the Healthcare Professional.” Mosby 2009. Accessed February 2014.
  • “Professional Guild to Pathophysiology.” Lippincott Williams and Wilkins 2010. Accessed February 2014.
  • World Health Organization. “Hospital Hygiene and Infection Control.” Accessed February 2014.
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