The average risk for human immunodeficiency virus (HIV) infection after a needlestick or cut exposure to HIV-infected blood is 0.3% (i.e., three-tenths of 1%, or about 1 in 300). Stated another way, 99.7% of needlestick and cut exposures do not lead to infection. The risk after exposure of the eye, nose, or mouth to HIV-infected blood is estimated to be, on average, 0.1% (1 in 1000). The risk after exposure of nonintact skin to HIV-infected blood is estimated to be <0.1%. A small amount of blood on intact skin probably poses no risk at all. There have been no documented cases of HIV transmission due to an exposure involving a small amount of blood on intact skin (a few drops of blood on skin for a short period of time).