Management of suspected or confirmed exposure to HIV

Australasian Society for HIV Viral Hepatitis and Sexual Health Medicine (ASHM) 2023

The advice on management of suspected or confirmed exposure to HIV in these guidelines apply to adults and children 16 years and older. Assessing the need for and prescribing postexposure prophylaxis (PEP) in adults and children 16 years and older is discussed in General principles for the management of suspected or confirmed exposure to HIV in adults and children 16 years and older.

Assessing the need for and prescribing PEP in children younger than 16 years is complex – see the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine (ASHM) Post-Exposure Prophylaxis After Non-Occupational and Occupational Exposure to HIV: Australian National Guidelines (Third edition) and seek expert advice.

Figure 1. General principles for the management of suspected or confirmed exposure to HIV in adults and children 16 years and older

The risk of HIV transmission from a single exposure is determined by the type of exposure and the HIV status of the source (or the likelihood that the source is HIV positive, if their status is unknown).

Testing requirements:

If the source is HIV antibody/antigen negative and unlikely to be in the window period, no further follow-up testing of the source or exposed person is required [NB1].
If the source is HIV antibody/antigen positive, or HIV antibody/antigen negative and likely to be in the window period, the exposed person should have HIV antibody/antigen testing at baseline, 4 to 6 weeks and 3 months after exposure. In people who do not receive HIV postexposure prophylaxis (PEP), the likelihood of seroconversion 6 weeks after exposure using a current standard assay (4th generation) HIV antibody/antigen test is very low. People that receive HIV PEP should have HIV antibody/antigen testing 3 months after exposure, as there is some evidence of delayed seroconversion in this cohort (ie seroconversion after completing a course of HIV PEP).

Postexposure prophylaxis (PEP):

Seek expert advice from a physician experienced in the management of HIV or consult local guidelines before initiating postexposure prophylaxis against HIV infection.
Recommendations for postexposure prophylaxis against HIV depend on the exposed person’s risk of acquiring HIV infection – see Postexposure prophylaxis (PEP) for adults and children 16 years and older with suspected or confirmed exposure to HIV. If indicated, start postexposure prophylaxis as soon as possible and within 72 hours after exposure. If it has been longer than 72 hours since exposure, seek expert advice – postexposure prophylaxis should only be offered in exceptional circumstances.
The recommendations in Postexposure prophylaxis (PEP) for adults and children 16 years and older with suspected or confirmed exposure to HIV do not apply to people taking HIV pre-exposure prophylaxis (PrEP). If the exposed person was taking PrEP at the time of exposure, see the Australasian Society for HIV Medicine (ASHM) Post-exposure prophylaxis after non-occupational and occupational exposure to HIV guideline.
Inform people receiving postexposure prophylaxis of the potential adverse effects of treatment and the possibility of drug interactions.

Pre-exposure prophylaxis (PrEP):

Consider Pre-exposure prophylaxis (PrEP) against HIV, depending on the exposed person’s risk of subsequent HIV infection. For more information on the estimated risk of HIV transmission based on the type of exposure, see the Australasian Society for HIV Medicine (ASHM) Post-exposure prophylaxis after non-occupational and occupational exposure to HIV guideline.

Note:

NB1: The window period refers to the time between infection and when HIV is detectable.

Table 1. Postexposure prophylaxis (PEP) for adults and children 16 years and older with suspected or confirmed exposure to HIV
Australasian Society for HIV Viral Hepatitis and Sexual Health Medicine (ASHM) 2023

[NB1]
Type of exposure: Anal intercourse Vaginal intercourse Oral intercourse Nonoccupational or occupational mucous membrane or nonintact skin exposure to source bodily fluid Occupational needlestick injury or sharps exposure Needlestick injury from discarded needle in community Human bite Shared needles and other injecting equipment
Anal intercourse
Source HIV status	PEP recommendation	Additional notes
source HIV positive and not taking antiretroviral treatment, or taking treatment but viral load detectable or unknown	use 3-drug regimen	–
source HIV positive but viral load undetectable	PEP not recommended	PEP is not recommended if the source provides a reliable history, adheres to antiretroviral therapy, is reviewed regularly and has no other sexually transmissible infections.
HIV status of source unknown	very high prevalence population (men who have sex with men who also inject drugs): use 3-drug regimen high prevalence population (men who have sex with men or from a high-prevalence country): PEP not recommended unless the sexual exposure was receptive anal sex, or insertive anal sex and the person is uncircumcised; if so, use 2-drug regimen	A high-prevalence country has more than 1% HIV prevalence in the general population. For seroprevalence in individual countries, see the UNAIDS Key Populations Atlas.
Vaginal intercourse
Source HIV status	PEP recommendation	Additional notes
source HIV positive and not taking antiretroviral treatment, or taking treatment but viral load detectable or unknown	use 3-drug regimen	–
source HIV positive but viral load undetectable	PEP not recommended	PEP is not recommended if the source provides a reliable history, adheres to antiretroviral therapy, is reviewed regularly and has no other sexually transmissible infections.
HIV status of source unknown	very high prevalence population (men who have sex with men who also inject drugs): use 3-drug regimen Source is not from a very high prevalence population: PEP not recommended
Oral intercourse
Source HIV status	PEP recommendation	Additional notes
source HIV positive or HIV status unknown	PEP not recommended	The estimated risk of HIV transmission from oral intercourse is so low as to be unmeasurable.
Nonoccupational or occupational mucous membrane or nonintact skin exposure to source bodily fluid
Source HIV status	PEP recommendation	Additional notes
source HIV positive and not taking antiretroviral treatment, or taking treatment but viral load detectable or unknown	use 3-drug regimen (except for the instances outlined in additional notes)	Unless contaminated with blood, PEP is not recommended for exposure to any of the following bodily fluids: urine, faeces, gastric secretions, vomit, nasal secretions, saliva, sputum, sweat or tears.
source HIV positive but viral load undetectable	PEP not recommended	–
HIV status of source unknown	very high prevalence population (men who have sex with men who also inject drugs): use 3-drug regimen while awaiting source test results (if testing possible)	–
Occupational needlestick injury or sharps exposure
Source HIV status	PEP recommendation	Additional notes
source HIV positive and not taking antiretroviral treatment, or taking treatment but viral load detectable or unknown	use 3-drug regimen	–
source HIV positive but viral load undetectable	consider 2-drug regimen	Assess the role of PEP for an individual on a case-by-case basis. Factors that may influence decision making include whether there was deep trauma and whether a bolus of blood was injected.
HIV status of source unknown	very high prevalence population (men who have sex with men who also inject drugs): use 3-drug regimen while awaiting source test results (if testing possible)	–
Needlestick injury from discarded needle in the community
Source HIV status	PEP recommendation	Additional notes
source HIV positive	not applicable	–
HIV status of source unknown	PEP not recommended	–
Human bite
Source HIV status	PEP recommendation	Additional notes
source HIV positive or HIV status unknown	PEP not recommended (except for the instances outlined in additional notes)	PEP should only be considered after a bite if all of the following apply: the biter’s saliva or mouth had visible blood there was a high suspicion that the biter was viraemic and not on treatment the bite has resulted in severe, deep or multiple tissue injuries.
Shared needles and other injecting equipment
Source HIV status	PEP recommendation	Additional notes
source HIV positive and not taking antiretroviral treatment, or taking treatment but viral load detectable or unknown	use 3-drug regimen	–
source HIV positive but viral load undetectable	consider 2-drug regimen	PEP is not recommended if the source: provides a reliable history adheres to antiretroviral therapy is reviewed regularly has no other sexually transmissible infections.
HIV status of source unknown	very high prevalence population (men who have sex with men who also inject drugs): use 3-drug regimen high prevalence population (men who have sex with men or from a high-prevalence country): use 2-drug regimen	A high-prevalence country has more than 1% HIV prevalence in the general population. For the seroprevalence in individual countries, see the UNAIDS Key Populations Atlas.
Note: NB1: The recommendations in this table do not apply to people taking HIV pre-exposure prophylaxis (PrEP). If the exposed person was taking PrEP at the time of exposure, see the Australasian Society for HIV Medicine (ASHM) Post-exposure prophylaxis after non-occupational and occupational exposure to HIV guideline.

For further information about initiating antiretroviral therapy, see Practice points for initial antiretroviral therapy, and Antiretroviral drug interactions.