This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
Risk of HIV transmission after needle stick injury is ? 
Select and explain. 
A. 0.30%, B. 0.5-1%, C. 2-3%, D. 10-20%
A: 0.30%
Answer: A: 0.30% 
Explanation: The average risk for HIV infection after a needlestick or cut exposure to HlV-infected blood is 0.3%.The risk after exposure of the eye, nose, or mouth to HIV-infected blood is estimated to be, on average, 0.1%.The risk after exposure of the skin to HlV-infected blood is estimated to be less than 0.1%. A small amount of blood on intact skin probably poses no risk at all.The risk may be higher if the skin is damaged (for example, by a recent cut), if the contact involves a large area of skin, or if the contact is prolonged.