190 likes | 530 Vues
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 .
E N D
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
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%
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