If the wound is superficial, the anaerobic environment cannot be formed inside the wound, and Clostridium tetani cannot survive, so there is no need for a tetanus shot, and the wound can be disinfected and bandaged. 2. If the instrument is sterile, such as disposable syringes or sterilized surgical instruments, there is no need for a tetanus shot after the scratch surgery because there is no Clostridium tetani above the instrument. 4, if the scratch is some iron, glass fragments in the mud, there is a large number of Clostridium tetani above, the scratch needs a tetanus shot to prevent infection. After the need to play tetanus injection to prevent infection.