Post-Exposure Prophylaxis Dr Michael J. Boyle

Common presentations Needle in the park Heterosexual sex - Vaginal - Oral Male to male sex - Anal - Oral Rape - Heterosexual - male to male Needle sharing / needle assault Other - trauma, dermatitis, broken skin exposure

Assessing the risk 1. The exposure - type of sex - type of injecting equipment - nature of injury (needle gauge) - nature and volume of body fluid - time since exposure 2. The source - Known +ve - source VL if known; Stage of HIV - If status unknown, ? epi risk

Management: First Steps Clean wound (soap and water) No Caustic agents Flush mucous membranes with saline Vaginal/rectal douching not recommended Assess tetanus hepatitis B vaccination status Organise pre-test counselling Risk assessment: risk of exposure X Source risk Factors that may enhance that risk assessment

Current HIV seroprevalence in Australia (0.066%) Type of Exposure Receptive anal intercourse Receptive vaginal intercourse Insertive vaginal or anal Needle injury Using contaminated needles Mucous membrane HIV Transmission Risk < 3.0% (1 in 125 to 1 in 30) < 0.1% (1 in 2000 to 1 in 667) < 0.1% (1 in 3333 to 1 in 1111) ~ 0.3% (1 in 313) ~ 0.6% (1 in 149) ~ 0.1% (1 in 1111) Current HIV seroprevalence in Australia (0.066%) Homosexual men 3-15% Injecting drug users ~1% Homosexual male IDU 17% Heterosexual STD clinic attendees 0.1% Blood donor 0.0005%

Exposure Source unknown Source Known Homosexual men Receptive anal 1 in 222 3% = 1 in 33.3 Insertive anal 0.1% x 15% = 1 in 6,666 0.1% = 1 in 1,000 Sharing needles 0.6% x 15% = 1 in 1,111 0.6% = 1 in 167 Non-intact skin ~ 0.6% = Mucous membrane ~ 0.1% = Heterosexual Receptive vaginal 0.1% x 0.1% = 1 in a million ~ 0.1%

Epidemiological risk varies

Other Risk Factors and Balancing Risk ? Patient viral load, treatment history ? Presence of STI in source or exposed person ? Ulcerative or inflammatory oral disease if oral sex ? Volume of blood if needle exposure 1 in 6 million for death from bee sting per year 1 in 5 million for childhood kidnap per year 1 in 2 million die by lightning strike each year 1 in 800 die due to smoking-related illnesses

Management: What needs to be discussed Pre-test counselling (may be delayed) Risk carefully explained HIV pep is NOT a proven therapy 4 week therapy (can be difficult) Protection for others (condom, needle sharing, breast feeding, blood donation, safe work practices) Side effects of drugs (don’t confuse seroconversion) Risks in pregnancy It is the choice of the patient and can stop anytime Need for follow-up Counselling and support ! ! ! ! !

Drug therapy Consider: Unprotected receptive or insertive anal intercourse Sharing needles and syringes Unprotected receptive or insertive vaginal sex Mucous membrane or non-intact skin exposure to HIV-positive blood Lesser risk, but consider Unprotected receptive fellatio if source known positive AND recipient Mucous membrane, non-intact skin exposure to HIV-infected secretions ALSO, source should be known positive, or at epidemiological high risk Also, consider whether presents within 72 hours

The drugs: which one 2 drugs most commonly: combivir Factor in drug history of source ALWAYS consult when prescribing 3 drugs if known Positive source AND advanced disease High viral load Has resistant virus Never use nevirapine

Document For exposed individual Nature, time of exposure, factors in exposure, time seen Recent HIV testing, previous exposures, pep use Current STIs; history of other STIs; Hep B,C history Pregnant? breast feeding? Significant medical disease, medication Discussion around PEP understanding, risk/benefit, treatment decision and what was recommended Consent for baseline testing after pre-test counseling: HIV, pregnancy, hepatitis B and C, blood count, LFT For source individual HIV stage, CD4 count, viral load, retroviral history, resistance tests hepatitis status, Hepatitis B infectivity, hepatitis C Viral load STI history: present and past infections

Management: what else to consider Tetanus Hepatitis B Hepatitis C Other STIs Sepsis (Staphylococcal infection in IDU)

Management: Hepatitis B If ever PROVEN immune to hepatitis B by vaccine or infection, no need for further therapy If non-immune, commence vaccination +/- HBIg within 72hours. If previously completed full vaccination >90% protected sAg positive; eAg, DNA positive: 30-40% sAg pos; eAg, DNA neg: < 6%

Hepatitis C Risks High prevalence in drug users If sero-positive, risk for needlestick 1.8% If RNA positive, risk of needlestick 10% Potential benefit of early treatment during seroconversion Follow up testing via serology +/- LFT, viral assessment

Follow up Post-test counselling 3 months follow up for HIV if no PEP 6 months follow up for HIV if PEP given 6 months follow up for hepatitis B and C Advice re avoiding future exposures