What is the recommended prophylaxis regimen for individuals exposed to bats?

Bat Exposure Prophylaxis Protocol

For individuals exposed to bats, the recommended post-exposure prophylaxis regimen consists of wound cleansing, human rabies immune globulin (HRIG), and a 4-dose rabies vaccine series administered on days 0,3,7, and 14. 1

Assessment of Bat Exposures

Bat exposures require special consideration due to the high risk of rabies transmission:

• Indications for prophylaxis:

  • Any bite from a bat
  • Physical contact with a bat when bite cannot be excluded
  • Sleeping in a room with a bat, especially if the person was deeply sleeping 2
  • Bat found in room with an unattended child or mentally impaired person 2

• No prophylaxis needed if:

  • The bat is captured and tests negative for rabies
  • Person was awake and certain no bite or mucous membrane exposure occurred 2

Post-Exposure Prophylaxis Protocol

1. Wound Management

• Immediately and thoroughly cleanse all wounds with soap and water 3
• Irrigate with virucidal agent such as povidone-iodine solution if available 1
• This local wound cleansing significantly reduces rabies transmission risk

2. For Previously Unvaccinated Individuals:

• Human Rabies Immune Globulin (HRIG):

  • Administer 20 IU/kg body weight 1
  • Infiltrate as much as anatomically feasible around and into the wound(s) 1
  • Administer any remaining volume intramuscularly at site distant from vaccine 1
  • Must be given with first vaccine dose (day 0), can be given through day 7 3

• Rabies Vaccine:

  • Human Diploid Cell Vaccine (HDCV) or Purified Chick Embryo Cell Vaccine (PCECV)
  • 1.0 mL administered intramuscularly in the deltoid area 1
  • 4-dose schedule: Days 0,3,7, and 14 1
  • For immunocompromised patients: 5-dose schedule (days 0,3,7,14, and 28) 1

3. For Previously Vaccinated Individuals:

• No HRIG needed 1
• Rabies Vaccine:
  • Two 1.0 mL doses of HDCV or PCECV administered intramuscularly in deltoid
  • Schedule: Days 0 and 3 only 1

Timing Considerations

• Begin prophylaxis immediately after exposure 2
• No absolute time limit for initiating PEP - should be given regardless of delay 2
• If bat can be captured, submit for testing - but do not delay PEP if testing will take time 2

Common Pitfalls to Avoid

1. Inappropriate administration sites: Vaccine must be administered in the deltoid area in adults and older children (never in gluteal area) 1

2. Inadequate wound infiltration: Failure to properly infiltrate HRIG around wounds increases risk of treatment failure 1

3. Delaying treatment: Substantial delays between exposure and prophylaxis increase risk, especially with head/face wounds 1

4. Underestimating bat exposures: Minor bat bites can go undetected but still transmit rabies 3

5. Waiting for animal testing: Do not delay PEP while waiting for bat testing if significant delay is expected 2

Effectiveness and Safety

• PEP is nearly 100% effective when administered properly according to guidelines 2
• Local reactions (pain, erythema at injection site) occur in up to 74% of recipients 1
• Mild systemic reactions (headache, nausea) occur in 5-40% of recipients 1
• Systemic allergic reactions are rare (approximately 11 per 10,000 vaccinees) 1

The 4-dose vaccine regimen (replacing the previous 5-dose regimen) has been shown to be equally effective while reducing healthcare costs and patient burden 1.