It is possible for a needle stick injury to cause an infection, but it is not necessary to be infected. It depends mainly on the depth of the needle prick and what kind of virus or bacteria this needle contains. If this needle is a needle for an intravenous infusion for a patient with an infectious disease, it is possible to transmit some disease after stabbing yourself at this time, but it has to be a disease that can be transmitted through blood. For example, influenza, it will not be transmitted through this needle, but only the blood side of the disease can be transmitted, such as AIDS, hepatitis B, hepatitis C and syphilis. In addition, this needle if the extent of the prick is only in the epidermis, there is a break in the epidermis, no bleeding, then generally speaking is not a big problem, but as long as there is a break in the skin, is also to bear the risk. Finally, whether the infection will be infected, but also depends on the needle prick injury after local cleaning and disinfection and afterwards whether the required treatment to block infection.