Post-exposure Prophylaxis

Hepatitis A

Human Normal Immunoglobulin (HNIG) or hepatitis A vaccine may be used depending on the clinical situation
- HNIG is typically reserved for those who cannot receive the vaccine or where rapid protection is required (e.g. immunosuppressed individuals)
- In most cases, hepatitis A vaccine is preferred for post-exposure prophylaxis

HBsAg positive source
- If the person exposed is a known responder (anti-HBs ≥10 mIU/mL following full vaccination), a booster dose should be given
- If they are a non-responder (anti-HBs <10 mIU/mL 1–2 months after completing the full course), they should receive hepatitis B immunoglobulin (HBIG) and a booster vaccine
Unknown source
- For known responders, a booster dose may be considered depending on the risk assessment
- For non-responders, HBIG and a booster vaccine should be given
- Individuals undergoing a primary course of vaccination should complete an accelerated schedule and may be offered HBIG if the risk of exposure is considered high

There is no effective post-exposure prophylaxis for hepatitis C
Initial testing should include baseline HCV serology and HCV RNA (PCR)
Repeat HCV RNA at 6 and 12 weeks post-exposure, and HCV antibody at 3 and 6 months
If seroconversion occurs, early referral to hepatology for consideration of direct-acting antiviral therapy is advised

The risk of HIV transmission depends on the nature of the exposure (e.g. needlestick, type of sexual contact, human bite) and the viral load of the source individual
Low-risk incidents such as human bites generally do not require post-exposure prophylaxis (PEP), unless blood is present or other risk factors apply
First-line PEP regimen is oral antiretroviral therapy: tenofovir disoproxil/emtricitabine (Truvada®) + raltegravir
- PEP should be started as soon as possible (ideally within 1–2 hours, and no later than 72 hours post-exposure)
- Treatment course lasts 4 weeks
HIV serological testing is required at 12 weeks after completing PEP
PEP reduces the risk of HIV transmission by approximately 80%

Varicella zoster immunoglobulin (VZIG) should be given to IgG-negative pregnant women or immunosuppressed individuals after significant exposure
- If VZIG is unavailable or >10 days post-exposure, oral aciclovir may be considered (based on risk assessment)