Does a human bite require rabies (Rabies virus) prophylaxis?

Human Bites Do Not Require Rabies Prophylaxis

Human bites do not require rabies post-exposure prophylaxis as humans are not known to transmit rabies through bites. 1, 2

Human-to-Human Rabies Transmission

• Human-to-human rabies transmission is extremely rare and has only been documented in the following circumstances:
  • Organ and tissue transplantation: 16 documented cases worldwide involving corneas (8 cases), solid organs (7 cases), and vascular tissue (1 case) 1
  • No laboratory-confirmed cases of human-to-human rabies transmission have ever been documented from bites or non-bite exposures 1
  • Two unconfirmed cases from Ethiopia suggested possible transmission through direct salivary contact (a bite and a kiss), but rabies was not laboratory-confirmed as the cause of death 1

Animal Bites Requiring Rabies Prophylaxis

Rabies post-exposure prophylaxis should be considered for the following animal exposures:

1. Bats: Even with minor or unrecognized bites 1, 2

   • All bat exposures should be carefully evaluated
   • PEP is indicated if a bat is found in a room with a sleeping person, unless the bat tests negative for rabies

2. Wild Terrestrial Carnivores: All bites from raccoons, skunks, and foxes 1

   • Postexposure prophylaxis should be initiated immediately unless the animal is available for testing and proves negative

3. Domestic Dogs, Cats, and Ferrets: Evaluation depends on circumstances and regional rabies prevalence 1

   • A healthy domestic animal that bites a person may be confined and observed for 10 days
   • Any illness in the animal during confinement should prompt immediate evaluation

Types of Exposures That Warrant Rabies Prophylaxis

• Bite exposures: Any penetration of skin by teeth from a rabid or potentially rabid animal 1
• Non-bite exposures: Contamination of open wounds, abrasions, mucous membranes with saliva or neural tissue from a rabid animal 1

Post-Exposure Prophylaxis Protocol

When indicated (which is NOT the case for human bites), PEP consists of:

• For previously unvaccinated individuals: Human Rabies Immune Globulin (HRIG) at 20 IU/kg body weight plus a 5-dose vaccine regimen on days 0,3,7,14, and 28 2
• For previously vaccinated individuals: Only 2 doses of vaccine (days 0 and 3) with no HRIG 2
• Thorough wound cleansing with soap and water, followed by irrigation with a virucidal agent such as povidone-iodine solution 2

Human Bite Management

While human bites do not require rabies prophylaxis, they do require appropriate management due to risk of bacterial infection:

• Thorough cleaning and copious irrigation with normal saline 3
• Exploration for tendon or bone involvement and possible foreign bodies 3
• Consider antibiotic prophylaxis, especially for high-risk wounds 3
• Amoxicillin/clavulanate is the first-line prophylactic antibiotic for human bites 3

Key Points to Remember

• Rabies is nearly 100% fatal once clinical symptoms develop, but PEP is nearly 100% effective when administered appropriately 4, 5
• Human bites pose risks for bacterial infection but not rabies transmission
• Always consult local or state public health officials for guidance in complex exposure situations 2

Human Medical Insights