No, a needlestick does not always cause bleeding, but the absence of bleeding does not negate the risk of infection.
Even if there's no visible blood after a needlestick injury, there's still a risk of viral infection. According to information, generally, needlestick injuries cause only minor visible trauma or bleeding; however, even in the absence of bleeding the risk of viral infection remains. This means that while bleeding can occur, it's not a guaranteed symptom, and regardless of whether bleeding is present, the potential for infection is still a concern.
Therefore, proper medical evaluation and follow-up are essential after any needlestick injury, irrespective of visible bleeding.
