Final answer:
Common causes of surgical site contamination include exposure to pathogens during medical procedures, the spread of infection from other areas of the body, and the contraction of iatrogenic diseases due to improper sterilization or cleanliness.
Step-by-step explanation:
The three most common causes of contamination of a surgical site can be traced to the introduction of pathogens through different routes. Firstly, pathogens can be introduced during medical procedures such as catheterization, dental procedures, piercings, or through existing wounds. Secondly, surgical site infections can arise from pathogens introduced through trauma or prosthetic joint replacements, or from the spread of infection from another body site via the bloodstream.
Lastly, iatrogenic diseases, which are contracted as a result of medical procedures, can occur if the wound or surgical site becomes contaminated due to factors like improper sterilization, contact with non-sterile surfaces or equipment, or by healthcare personnel who do not adhere to strict handwashing and cleanliness protocols.