What is considered to be a potential exposure to HIV, HBV or HCV?
For transmission of blood borne pathogens (HIV, HBV and HCV) to occur, an exposure must include both of the following:
• Infectious body fluid
o Blood, semen, vaginal fluids, amniotic fluids, breast milk, cerebrospinal fluid, pericardial fluid, peritoneal fluid, pleural fluid and synovial flood can transmit HIV, HBV and HCV.
• Note that saliva, vomitus, urine, feces, sweat, tears and respiratory secretions do not transmit HIV (unless visibly bloody). The risk of HBV and HCV transmission from non-bloody saliva is negligible.
• A portal of entry
(percutaneous, mucous membrane, cutaneous with non-intact skin).
If both of these factors are not present, there is no risk of transmission and further evaluation is not required.
What baseline testing should be performed after an exposure?
(If no exposure occurred or Source Person tests negative, no testing is clinically indicated. Testing may be considered for other purposes including medico legal concerns or as per institutional protocols.)
Source Person (SP):
• HIV Ab (rapid HIV Ab testing preferred if accessible)*
• HCV Ab
• HBV surface Ag
*If SP’s rapid HIV Ab test is positive, assume this is a true positive and send confirmatory testing, usually with a Western Blot test. See below*.
Exposed Person (EP):
• HIV Ab
• HCV Ab
• HBV testing: Depends on immunization status.
Note that most healthcare and public safety personnel have been vaccinated against hepatitis B. If previously vaccinated and they know they responded to the vaccination series (a positive titer is >10mIU/mL, but most do not know their titer), they are considered to have lifelong immunity and require no further testing or treatment. Similarly, if employee health records indicate they responded to the vaccination series, they are considered to be immune. For all others, see the “Exposures to HBV and HCV” section of this guide.
*Is the rapid HIV test accurate enough to decide on whether to give PEP?
Yes, the rapid HIV test is extremely sensitive and specific and can be used to determine whether to offer PEP. A positive rapid HIV test should be considered a true positive for the purposes of PEP decision-making. A negative rapid test should be considered a true negative. Investigation of whether a source might be in the “window period” is unnecessary for determining whether HIV PEP is indicated unless acute retroviral syndrome is clinically suspected.