Which factor increases the risk of tetanus in a wound?

The factor that increases the risk of tetanus in a wound is related to the depth and nature of the wound. Wounds that are greater than 1 cm in depth are more likely to become contaminated with tetanus bacteria because deeper wounds provide a more favorable environment for the bacteria. These deeper wounds often involve more devitalized tissue, blood supply compromise, and potential exposure to anaerobic conditions, all of which can facilitate the growth of Clostridium tetani, the bacterium responsible for tetanus.

In contrast, wounds less than 6 hours old and those that are clean and superficial typically carry a lower risk for tetanus. Fresh, clean wounds are less likely to harbor the bacteria, and superficial wounds do not provide the same conducive environment for bacterial proliferation as deeper wounds do. Thus, when assessing the risk of tetanus, the depth of the wound is a significant factor, making greater than 1 cm in depth a key characteristic that elevates the risk.