The probability of HIV transmission depends upon the exposure characteristics, the infectivity of the source, and host susceptibility. Where individuals have multiple exposures within 72h, a cumulative risk should be considered.
Risk of HIV transmission = risk that source is HIV positive x risk per exposure
We recommend the use of PEPSE where there is a signiﬁcant risk of HIV transmission (risk>1/1000). (1C).
Consider PEP when transmission risk is between 1 in 1000 and 1 in 10,000.
If the source is of unknown status:
We suggest proactive attempts are made to establish the HIV status of the source (2C).
If the source is individual from high prevalence country/risk group (eg: MSM), PEPSE is recommended in receptive anal sex
Source individual known to be HIV-positive:
Attempts should be made at the earliest opportunity to determine the HIV VL, resistance proﬁle and treatment history (1D)
PEPSE is no longer recommended if the source is on ART with a conﬁrmed and sustained (>6 months) and undetectable plasma HIV VL (<200 c/mL) (1B).
If drug resistance is suspected in the source, the regimen should be tailored accordingly following discussion with an HIV specialist (1D).
PEPSE is recommended in receptive and/or insertive anal sex, receptive vaginal sex, and sharing injecting equipment with HIV positive individual on ART with viral load > 200 copies/ml.
The ﬁrst-line regimen is Truvada and Raltegravir for 28 days.
The table below summarises recommended combinations for PEP.
PEPSE should be initiated as soon as possible after exposure but can be considered up to 72h (1D)
Duration of PEPSE should be 28 days (1D).
PEPSE should not be considered or encouraged as a ﬁrst-line method of HIV prevention. Other more evidence-based methods should be discussed (1C).
Individuals seeking PEPSE should be encouraged to attend for future regular sexual health check-ups (2C).
An accurate medication history should be obtained, including use of over the counter medications, vitamins/minerals, herbal remedies, and recreational drugs before PEPSE is prescribed (1D).
Routine blood test monitoring after initiation of raltegravir-based PEPSE is not necessary unless clinically indicated or if baseline blood tests are abnormal (2C).
Offer STI screen at baseline as indicated, as well as at two weeks post-exposure (2C).
Follow-up HIV testing at 8–12 weeks after exposure (1C).
4th generation laboratory venous blood HIV test at baseline and for follow-up testing (1D).
Offer an ultra-rapid course of hepatitis B vaccination if clinically indicated and the individual has no immunity at baseline (GPP).
Offer pregnancy testing in women considering PEPSE (1D).
Women must be counselled that antiretroviral agents used for PEPSE are unlicensed in pregnancy and risks/beneﬁts must be carefully discussed (1D)
In the event of a further high-risk sexual exposure in the last two days of the PEPSE course, the PEP should be continued for 48h after the last high-risk exposure (2B).
Individuals experiencing a skin rash or ﬂu-like illness during or after taking PEPSE should be advised to attend for urgent review to exclude an HIV seroconversion illness (2D).
If the HIV test is positive after PEPSE has already been initiated, we recommend continuing PEPSE pending review by an HIV specialist (GPP).
Information about PEPSE should be included when counselling individuals at risk of acquiring HIV infection as well as those already diagnosed with HIV infection (2D).