The risk of infection among HCP following percutaneous exposure to HIV-infected blood is more likely (1) in the presence of visible blood on the instrument before injury, (2) if the injury involved a needle that was placed directly into the patient’s vein or artery, (3) if the injury caused by the contaminated instrument or needle was deep, or (4) if the source patient has high viral load.27-30 The risk of transmission with OPIM is probably lower than with blood.31,32
Prospective studies estimate that the average risk for HIV infection after percutaneous and mucous membrane (eyes, nose, and mouth) exposure to HIV-infected blood is approximately 0.3% (1 infection associated with 2,885 exposures) and 0.09%, respectively.31,33 The transmission of HIV infection after nonintact skin exposure is estimated to be less than the risk following mucous membrane exposure.34,35 The risk of infection associated with intact skin is below detection.
Since HIV was first isolated, only 4 instances of HIV transmission from infected provider-to-patient have been documented worldwide and no cases have been reported since 2003.36 The U.S. cluster involved a dentist with AIDS. All HIV isolates were linked to the dentist, but the precise mechanisms of transmission were never determined. Since then, more than 4 dozen look-back studies have been conducted and none of these studies identified evidence of provider-to-patient transmission.36