Recommendations to Reduce the Risk of Occupational
HIV Transmission After an Exposure Incident

Risk of HIV Transmission

The average risk of HIV infection from all types of percutaneous exposures to HIV-infected blood is 0.3 percent.  The Centers for Disease Control and Prevention (CDC) conducted a case-control study to determine the risk of HIV infection from different types of percutaneous exposures.  This case control study showed that the risk of HIV infection exceeded 0.3 percent for exposures that involved a deep injury to the health care worker; visible blood on the device that caused the injury; a device had been placed in the source-patient's vascular system, (e.g., a needle used for phlebotomy); or a source patient died as a result of AIDS within 60 days postexposure.³

The increased risk associated in these scenarios may be related to exposure to larger volumes of blood, or to blood containing a higher titer of the HIV virus.  However, the utility of viral load measurements from the source-patient as a surrogate for estimating the viral titer for assessing transmission risk is unknown.  HIV transmission from those with a viral load below detectable limits has been reported in one health care worker seroconversion and in instances of mother-to-infant transmission.^3,4

The average risk of HIV infection following a mucous membrane or skin exposure is less than the risk associated with a percutaneous exposure.  The average risk of HIV infection after a mucous membrane exposure is 0.09 percent.  The average risk of HIV infection after a skin exposure is less than 0.09 percent.  The risk for skin exposure may be increased if skin contact is prolonged, if contact involved an extensive area of the skin, if the integrity of the skin is not intact, or if the exposure involves a higher titer of HIV.³