Rabies Post Exposure Prophylaxis (PEP)

Clinical assessment

Assessment based on: History of exposure (type of animal, vaccination status of animal if known, circumstances of bite - provoked/unprovoked, type of contact - bite/scratch/lick). Local wound examination. Assessment of the animal's status (healthy, suspect, rabid, unavailable). Decision for PEP is based on risk assessment, not waiting for human symptoms.

Investigations

• Animal Assessment (Crucial):
• - If domestic dog/cat identified & healthy: Quarantine and observe for 10 days. If remains healthy, PEP may not be needed or can be stopped.
• - If animal shows signs suggestive of rabies, or is a wild animal, or cannot be identified/observed: Assume rabid and initiate PEP.
• - Laboratory confirmation in animals: Requires brain tissue examination (Veterinary Department).
• Human Assessment: Wound evaluation. Tetanus status check.
• Rabies diagnostics in humans are complex and usually done postmortem or late in illness; PEP is given based on exposure risk.

Diagnostic criteria

Decision to initiate PEP based on UCG Table (p.38) combining Nature of Exposure (skin contact, minor bite, severe bite/mucosal contact) and Condition of Animal (healthy, rabid, suspect/unknown). Severity of bite (face/head/hands/multiple bites) influences need for RIG.

Non-pharmacological management

• Immediate Local Wound Treatment (CRITICAL for all exposures): Prompt, thorough washing and flushing of the wound for at least 15 minutes with soap and copious amounts of water. Follow with application of antiseptic (e.g., Povidone iodine, Chlorhexidine, alcohol).
• DO NOT SUTURE the wound primarily. If closure is unavoidable, it should be loose after infiltration with RIG (if indicated) and delayed if possible.
• Determine need for PEP based on risk assessment (Exposure type + Animal status).

Pharmacological treatment

• Tetanus Prophylaxis: Administer TT booster if indicated.
• Rabies Vaccine (RV) - Active Immunization:
• - For ALL exposures requiring PEP (minor/severe bites, mucosal contact from suspect/rabid/unknown animal).
• - Use Purified Vero Cell Rabies Vaccine (PVRV) or similar cell culture vaccine (e.g., PCECV).
• - Regimens (for non-previously vaccinated):
• - Intramuscular (IM) 2-1-1 Regimen: Day 0: One 0.5ml dose in EACH deltoid (total 2 doses). Day 7: One 0.5ml dose (deltoid). Day 21: One 0.5ml dose (deltoid). (Total 4 doses). [Anterolateral thigh in young children]. NEVER give in gluteal region.
• - Intradermal (ID) 2-site Regimen (Alternative, cost-saving): Day 0: One 0.1ml dose ID in EACH deltoid. Day 3: One 0.1ml dose ID in EACH deltoid. Day 7: One 0.1ml dose ID in EACH deltoid. Day 28: One 0.1ml dose ID in EACH deltoid. (Total 8 ID doses = 1.6 IM doses). Requires specific training, syringes, needles. Do NOT use if patient on chloroquine malaria prophylaxis.
• - For previously fully vaccinated patients (within 3 years): Give booster doses only. IM regimen: One 0.5ml dose IM on Day 0 and Day 3. ID regimen: One 0.1ml dose ID on Day 0 and Day 3.
• Rabies Immunoglobulin (RIG) - Passive Immunization:
• - Indicated for SEVERE exposures (Category III): Saliva contact with mucous membranes, serious bites (face, head, neck, hands, fingers, genitalia, multiple bites), OR any bite/scratch from a confirmed/highly suspected rabid animal (including bats).
• - Give ONLY ONCE at the beginning of PEP (Day 0). Should be given concurrently with the first RV dose, but up to 7 days after first RV dose if initially unavailable.
• - DO NOT give RIG to previously fully vaccinated individuals.
• - Human RIG (HRIG): Dose = 20 IU/kg body weight.
• - Equine RIG (ERIG): Dose = 40 IU/kg body weight (higher risk of hypersensitivity - perform skin test if recommended by manufacturer).
• - Administration: Infiltrate as much of the calculated RIG dose as anatomically feasible directly into and around the wound edges. Give any remaining volume by deep IM injection at a site distant from RV injection (e.g., opposite gluteal muscle or thigh). If multiple wounds, may dilute RIG 2-3 fold with saline to cover all sites.
• Antibiotics: Consider prophylactic antibiotics for the bite wound itself based on standard bite wound criteria (See TRA004).

Monitoring

Ensure completion of the full vaccine schedule. Monitor wound site for infection. Monitor for adverse reactions to vaccine or RIG (rare with modern vaccines/HRIG).