Provision of PEP should not be delayed while establishing the source HIV status. Informed consent should be sought from the source when performing an HIV test.
It is important to note the sensitivity of gathering information on an individual’s HIV status and ensure the source individual’s privacy and confidentiality.
If the source is contactable and
- discloses they are HIV positive:
- consent should be requested to seek further information from their treating physician
- information requested should include source treatment status, last HIV viral load and history and suspicion of any antiretroviral resistance
- is HIV negative and confirmed to be taking HIV PrEP as prescribed:
- PEP is not indicated
- chooses not to disclose their HIV status or have an HIV test:
- PEP should be considered based on the risk exposure outlined in Table 2 under Source of unknown HIV status
When a source individual is known to have HIV, knowledge of their treatment status, last viral load (VL) and history of any antiretroviral resistance can be useful in determining whether PEP is indicated and whether a non-standard PEP regimen is required due to previous detection or suspicion of antiretroviral resistance mutations.16 When this information is unavailable or the source is not contactable, the guidance for specific exposures in Table 2 under Source of unknown HIV status should be followed. Provision of PEP should not be delayed while establishing the source’s HIV status, and informed consent should be sought from the source when performing an HIV test. Disclosure of a person’s HIV status can be confronting for them, so their confidentiality should be assured as far as possible.
In non-occupational exposure where the source status is unknown, ideally an attempt should be made to contact the source to request an urgent HIV test. This procedure should not delay the commencement of PEP, and again, recommendations for Source of unknown HIV status outlined in Table 2 should be followed. In the occupational setting, the source can often be identified and tested for HIV, and, if indicated, HIV VL and a history of antiretroviral failure and resistance obtained. Nonetheless, a healthcare worker exposed to HIV should be commenced on PEP without delay, pending the result(s). If the source HIV antigen/antibody (Ag/Ab) test is negative, PEP may be discontinued or modified in discussion with the healthcare worker, noting that in very early HIV infection in the source a negative HIV test may not be accurate.
The three-drug recommendation for exposures to sources who are MSM and also people who inject drugs (PWID) is based on the calculation that the HIV infection and viraemia rate per 1000 in this population is over 13-fold higher than among MSM who do not inject drugs (Appendix A, Table 9).
|Estimated risk of HIV|
transmission/exposure*Source A known HIV positive
(Refer to tables in Appendix A)
|Source of unknown HIV status
(Refer to tables in Appendix A)
|HIV VL unknown or detectable||HIV VL undetectable||Very high prevalence population B (MSM who injects drugs)||High prevalence population B (MSM or from HPC)|
|Sexual exposure C,D|
|Receptive anal sex||3 drug||NR||3 drug||2 drug|
|Insertive anal sex |
|3 drug||NR||3 drug||2 drug|
|Insertive anal sex |
|3 drug||NR||3 drug||NR|
|Receptive vaginal sex||3 drug||NR||3 drug||NR|
|Insertive vaginal sex||3 drug||NR||3 drugs||NR|
|Semen splash into eye||NR||NR||NR||NR|
|Occupational and other exposuresE|
|Shared injecting equipment||3 drug||Consider 2 drug||3 drug||2 drug|
|Occupational needle-stick injury||3 drug||Consider 2 drug||3 drug||NR|
|Mucosal exposure/splash injury to infectious fluids||3 drugs||NR||3 drug||NR|
|Human bite E||NR||NR||NR||NR|
|Community needle-stick injury||NR||NR||NR||NR|
HPC: high-prevalence country (defined as population prevalence above 1%)
MSM: men who have sex with men;
VL : HIV viral load;
* A low prevalence population is defined as a population or specific subgroup of the population with an HIV prevalence below 1% (e.g. men other than MSM, general population of Australia who do not inject drugs).
# Consider two-drug PEP only where receptive fellatio WITH ejaculation AND significant visible oral mucosal trauma, or dental and gum disease.
A The person whose blood or other bodily substance may be a source of HIV exposure.
B ‘Very high’ and ‘high’ prevalence populations are those with a significant likelihood that the source is HIV positive and may be viraemic. In Australia, this is principally MSM who inject drugs, MSM who do not inject drugs, people who inject drugs from high-risk countries especially from central Asia and Eastern Europe (see: The Gap Report 2014 – People Who Inject Drugs) and migrants from areas of high HIV prevalence, particularly sub-Saharan Africa (see: AIDSinfo UNAIDS). Recommendations for PEP have been separated in this version of the guidelines given that in Australian populations, the HIV infection and viraemia rates per 1000 population are estimated to be over 13-fold higher among MSM who inject drugs versus MSM who do not inject drugs: currently 156/1000 compared to 12.0/1000 respectively46-49 (Appendix A, Table 9).
C Sexual exposure assumes no condom use or condom failure. Sexual exposures also include those in female and male sex workers in Australia. Rates of HIV infection and viraemia in these people are similar to the populations they belong to. NOTE: The rates of HIV infection and viraemia in female sex workers in other parts of the world (for example, Southeast Asia) may be significantly higher, and PEP may be considered.
D Co-factors that may influence decision-making following sexual exposures: (a) breaches in the mucosal barrier such as genital ulcer disease and anal or vaginal trauma following sexual assault or first intercourse; (b) multiple episodes of exposure within a short period of time e.g. group sex; (c) a sexually transmissible infection (STI) in either partner.
E Co-factors that may influence decision-making following occupational exposures: (a) deep trauma; (b) bolus of blood injected.
F PEP should only be considered after a bite if: (a) the biter’s saliva or mouth had visible blood, AND (b) there was a high suspicion that the biter was viraemic and not on treatment, AND (c) the bite has resulted in severe, deep or multiple tissue injuries.
3 drug: three-drug PEP recommended
2 drug: two-drug PEP recommended
Consider two-drug PEP: the benefits of PEP are less clear and should be balanced against the risks, including consideration of co-factors (see footnotes of Table 1), which may increase risk of HIV acquisition
NR: PEP not recommended
N/A: not applicable