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

Hepatitis B

• 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

Hepatitis C

• 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

HIV

• 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

• 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)

Estimates of transmission risk for single needlestick injury