What is the treatment for Human Rabies (HR) exposure?

Treatment for Human Rabies Exposure

The essential components of rabies postexposure prophylaxis are immediate wound treatment and, for previously unvaccinated persons, administration of both human rabies immunoglobulin (HRIG) and rabies vaccine, regardless of the time interval between exposure and treatment initiation. 1

Initial Assessment and Wound Management

• Immediate and thorough cleansing of all bite wounds and scratches with soap and water or dilute povidone-iodine solution is critical and can markedly reduce the likelihood of rabies transmission 1
• Wound cleansing should be gentle but thorough, taking care not to damage skin or tissues 1
• Consider tetanus prophylaxis based on vaccination history 1
• Evaluate need for antibiotic prophylaxis based on wound characteristics, animal species, and time since bite 1
• Avoid suturing wounds when possible to prevent deeper inoculation of virus 1

Postexposure Prophylaxis (PEP) Protocol

For Previously Unvaccinated Persons:

1. Human Rabies Immunoglobulin (HRIG):

   • Administer 20 IU/kg body weight (single dose only) 1, 2
   • Infiltrate the full dose around and into the wound(s) if anatomically feasible 1
   • Any remaining volume should be administered intramuscularly at a site distant from vaccine administration 1
   • If not administered at initiation of PEP, HRIG can be given up to day 7 of the vaccination series 1

2. Rabies Vaccine:

   • Administer a 5-dose regimen of 1 mL per dose intramuscularly 1
   • Schedule: Days 0,3,7,14, and 28 1
   • For adults: administer in the deltoid area only 1
   • For children: deltoid or anterolateral thigh are acceptable 1
   • Never administer in the gluteal area (leads to lower antibody titers) 1

For Previously Vaccinated Persons:

• Administer only vaccine (no HRIG) 1
• Two 1-mL doses of vaccine intramuscularly 1
• Schedule: Days 0 and 3 1

Special Considerations

• PEP is a medical urgency, not an emergency, but decisions should not be delayed 1
• Administer PEP regardless of the time elapsed since exposure, as rabies can have incubation periods exceeding 1 year 1
• PEP can be discontinued if the exposing animal is confirmed negative for rabies by laboratory testing 1
• PEP is ineffective once clinical signs of rabies appear in the exposed person 1, 3
• The combination of HRIG and vaccine has been shown to be safe and effective, with no documented failures in the United States when properly administered 1, 4

Risk Assessment for PEP

• Consider the following factors when determining need for PEP:
  • Type of exposure (bite vs. nonbite) 2
  • Species, vaccination status, and behavior of the animal 1
  • Epidemiology of rabies in the region 1
  • Provoked vs. unprovoked attack 1
  • For bats, PEP should be considered when physical contact occurs and a bite cannot be excluded 2

Common Pitfalls and Caveats

• Never administer HRIG and vaccine in the same anatomical site or syringe 1
• Do not exceed recommended HRIG dose as it may partially suppress active antibody production 1
• Failure to thoroughly infiltrate wounds with HRIG has been associated with rare PEP failures 1
• Rabies is nearly 100% fatal once clinical symptoms develop, emphasizing the critical importance of proper PEP 5, 3
• For exposures in countries with endemic canine rabies, consider immediate initiation of PEP, which can be discontinued if the animal remains healthy during observation 1

Human rabies postexposure prophylaxis is highly effective when administered properly, with no documented failures in the United States since current biologics have been licensed 1, 5.