What are the guidelines for post-exposure prophylaxis (PEP) after rabies exposure?

Rabies Post-Exposure Prophylaxis Guidelines

Rabies post-exposure prophylaxis (PEP) should begin immediately with thorough wound cleansing followed by both rabies immune globulin (RIG) and vaccination, regardless of the interval from exposure, as this approach is nearly 100% effective in preventing this otherwise fatal disease. 1, 2

Initial Assessment and Decision-Making

Types of Exposure Requiring PEP

1. Bite exposures: Any penetration of skin by teeth 3, 2
2. Non-bite exposures: Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or neural tissue 2
3. Bat exposures: Any physical contact with bats when bite or mucous membrane contact cannot be excluded, even if no visible bite is detected 2

Animal Risk Assessment

• High-risk animals: Consider rabid unless proven negative by laboratory testing 2, 4

  • Skunks, raccoons, foxes, coyotes, bats, bobcats, woodchucks
  • Dogs and cats that are rabid or suspected rabid
  • Unknown/escaped animals (consult public health officials)

• Lower-risk situations: 2, 4

  • Healthy dogs/cats available for 10-day observation (no PEP unless animal develops rabies)
  • Small rodents (squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, mice) rarely require PEP
  • For livestock and other mammals, consult public health officials

PEP Protocol

Step 1: Immediate Wound Care

• Thoroughly wash and flush all wounds with soap/cleansing agent and copious amounts of water for at least 15 minutes 1, 2, 5
• Apply iodine-containing or viricidal topical preparation if available 2, 4
• Provide tetanus prophylaxis and antibacterial treatment as indicated 2

Step 2: Rabies Immune Globulin (RIG)

• Administer 20 IU/kg body weight 1
• Infiltrate the full dose around and into all wounds if anatomically feasible 1, 2
• Administer any remaining volume intramuscularly at a site distant from vaccine administration 1
• Do not exceed recommended dose as it may suppress antibody production 1
• Do not administer RIG to previously vaccinated individuals 1, 2

Step 3: Vaccination Schedule

• For previously unvaccinated individuals: 1, 4

  • Standard 4-dose regimen: 1.0 mL IM injections on days 0,3,7, and 14
  • Administer in deltoid muscle for adults/older children or anterolateral thigh for younger children
  • For immunocompromised patients: 5-dose regimen on days 0,3,7,14, and 28

• For previously vaccinated individuals: 1

  • 2-dose regimen: 1.0 mL IM injections on days 0 and 3 only
  • No RIG required

Special Considerations

Timing of PEP

• Initiate as soon as possible after exposure, ideally within 24 hours 1
• Can still be beneficial when administered at any time before symptom onset, even months after exposure 1

Immunocompromised Patients

• Corticosteroids and other immunosuppressive agents can interfere with vaccine response 3
• Immunosuppressive agents should not be administered during PEP unless essential 3
• Serologic testing recommended to ensure adequate antibody response 3, 1

Pregnancy

• Pregnancy is not a contraindication to PEP 3
• The potential consequences of inadequately treated rabies exposure outweigh any theoretical risk to the fetus 3

Management of Adverse Reactions

• Do not discontinue PEP due to local or mild systemic reactions 3
• For patients with history of serious hypersensitivity, administer antihistamines before vaccination 3
• Have epinephrine readily available for anaphylactic reactions 3

Common Pitfalls to Avoid

1. Delayed initiation of PEP (start immediately after exposure) 1, 5
2. Improper RIG administration (failure to infiltrate wounds properly) 1
3. Incorrect injection site for vaccine (must be in deltoid for adults, not gluteal) 1
4. Inadequate wound cleansing (must be thorough for at least 15 minutes) 1, 5
5. Discontinuing PEP due to mild adverse reactions 3
6. Exceeding recommended RIG dose which may suppress antibody production 1

When to Consult Public Health Officials

• For exposures to uncommon species 2, 4
• When the animal has escaped and cannot be tested 2, 4
• For any questions about the need for rabies prophylaxis 3, 1
• For management of serious adverse reactions 3

Remember that rabies is nearly 100% fatal once clinical symptoms develop, but PEP is nearly 100% effective when administered correctly and promptly 1.