Post-exposure prophylaxis (PEP) involves taking antiretroviral drugs after potential exposure to HIV to prevent infection. Studies show a transmission rate of 0.33% from needlesticks and 0.09% from mucosal exposures to HIV-infected sources. Nurses and lab technicians made up most occupational transmissions. PEP drug regimens use 2-3 antiretrovirals started within 24 hours for 4 weeks. While animal studies show high protection when started early, human cases still seroconvert, indicating efficacy below 100%. Timing and duration of PEP are based on CDC and WHO guidelines.

1. PEP(Post-Exposure Prophylaxis) Dr TIN MAUNG CHIT CONSULTANT PHYSICIAN PGH

2. How is Post-exposure prophylaxis carried out?

3. Risk of transmission A total of 23 studies of needle sticks among healthcare workers demonstrate HIV transmission in 20 of 6135 (0.33%) exposed to an HIV infected source.( Ann of Intern Med 1990;113;740) with mucosal surface exposure there was one transmission in 1143 exposures (0.09%) and there was no transmission in 2712 skin exposures.

4. Risk of viral transmission with sharps injury from infected source 2003 Johns Hopkins HIV guide

5. Of 56 confirmed HIV transmission in the occupational setting in USA Nurses 23 Lab Techs 20 Physicians 6 Type of exposure Percutaneous 48 Mucocutaneous 5 Both 2MMWR June 29, 2001 / 50(RR11);1-42

6. Post exposure prophylaxis for percutaneous injury (MMWR June 29, 2001:50(RR11);1-42)

7. Drugs used for PEP 2 drug combinations Zidovudine + Lamivudine Lamivudine + Stavudine Stavudine + didanosine 3 Drug combination Above list + indinavir, nelfinavir, efavirenz, abacavir, ritonavir or lopinavir/ ritonavirMMWR June 29, 2001:50(RR11);1-42

8. Expanded regimens for PEP if source patient is already receiving ART the drug regimen for PEP will depend on what drugs the source patient is taking and the possibility of drug resistance in the source.MMWR June 29, 2001:50(RR11);1-42

9. Evidence of Efficacy of PEP animal models: high level of protection when started within 24 hours1 79% reduction of transmission with zidovudine use in case-control study2 two drugs, three drugs: no direct evidence that more effective than 1 drug cases of seroconversion despite 3-drug PEP imply efficacy less than 100%3,4 1. Tsai C-C et al. J Virol 1998;72:4265-73. 2. Cardo DM et al. NEJM 1997;337:1485-90. 3. Jochinsen EM et al. Arch Int Med 1999;159:2361-3. 4. MMWR June 29, 2001 / 50(RR11);1-42

10. Timing of PEP MMWR June 29, 2001:50(RR11);1-42

11. Duration of PEP 4 weeks (28 days) used in case-control study2 and recommended by CDC / WHO guidelines3 1. Tsai C-C et al. J Virol 1998;72:4265-73. 2. Cardo DM et al. NEJM 1997;337:1485-90. 3. MMWR June 29, 2001:50(RR11);1-42.

12. Post-Exposure Prophylaxis: Core Principles

13. THANK YOU