Regarding the use of tetanus for a small wound caused by a kitchen knife, it is mainly based on the width and depth of the wound, the degree of openness and the hygiene of the kitchen knife, such as the presence or absence of rust stains. If a relatively clean kitchen knife touches a superficial open wound, tetanus is not necessary. Wounds that are more likely to cause tetanus are characterized by deep, narrow, closed and airtight wounds and poor cleanliness, such as wounds formed by rusty nails in construction sites or buried in the soil, because tetanus bacillus is an anaerobic bacterium that does not easily grow and multiply when the wound is open and airtight. The above description is based on the reproduction habits of tetanus bacillus and the characteristics of tetanus infection, but the specific need for tetanus depends on the specific circumstances, and does not rule out that chopper wounds can also be characterized by the above. It is recommended that superficial open wounds should be observed for the time being, and if symptoms of tetanus or other infections occur, prompt medical attention should be sought to take appropriate measures.