What is the appropriate treatment for a patient bitten by a stray cat, with a puncture wound and up-to-date tetanus vaccinations, but no prior rabies vaccination?

Rabies Post-Exposure Prophylaxis for Stray Cat Bite

This patient requires immediate rabies vaccine and rabies immunoglobulin (Option B), along with thorough wound care. Since the patient has no prior rabies vaccination and was bitten by a stray cat of unknown rabies status, full post-exposure prophylaxis is mandatory regardless of the cat's apparent health.

Rationale for Rabies Post-Exposure Prophylaxis

The combination of rabies immunoglobulin (RIG) and vaccine is recommended for all previously unvaccinated persons exposed to animals of unknown rabies status, regardless of the time interval between exposure and treatment initiation. 1 This applies to both bite and nonbite exposures. 1

Why Observation Alone is Inadequate

• Stray cats cannot be reliably observed for the required 10-day period to rule out rabies, making immediate prophylaxis necessary. 1, 2, 3
• The cat's apparent health status at the time of the bite is irrelevant—rabies can be transmitted before clinical signs appear in the animal. 1
• Rabies is 100% fatal once clinical symptoms develop in humans, making prevention through PEP the only viable strategy. 1, 4

Complete Post-Exposure Prophylaxis Protocol

1. Immediate Wound Management

Thorough wound cleansing is critical and should begin immediately:

• Wash the puncture wound with soap and water for approximately 15 minutes. 1, 4
• If available, irrigate with a virucidal agent such as povidone-iodine solution. 1
• Wound cleansing alone has been shown in animal studies to markedly reduce rabies transmission risk. 1

2. Rabies Immunoglobulin Administration

Administer 20 IU/kg body weight of human rabies immunoglobulin (HRIG) as soon as possible:

• If anatomically feasible, infiltrate the full dose thoroughly into and around the puncture wound. 1, 2
• Any remaining volume should be administered intramuscularly at a site distant from vaccine administration (deltoid or lateral thigh, never gluteal). 1, 2
• RIG can be given up to 7 days after the first vaccine dose, but should ideally be given on day 0. 1
• Never administer RIG in the same syringe or anatomical site as the vaccine. 1, 2

3. Rabies Vaccine Series

Administer a 4-dose vaccine regimen (HDCV or PCECV) intramuscularly:

• Days 0,3,7, and 14 (the 2010 ACIP guidelines reduced this from the previous 5-dose schedule). 1
• Administer in the deltoid area for adults and older children; anterolateral thigh for younger children. 1
• Never use the gluteal area due to risk of sciatic nerve injury and reduced immunogenicity. 1, 2

4. Tetanus Prophylaxis

Since the patient is up-to-date with tetanus vaccination, tetanus immunoglobulin is NOT indicated. 1 However:

• Verify the patient's tetanus status is truly current (last dose within 5 years for dirty wounds, 10 years for clean wounds). 1, 5
• If there is any doubt about vaccination status, administer tetanus toxoid 0.5 mL intramuscularly. 5

Why Other Options Are Incorrect

Option A (Tetanus Vaccine and Immunoglobulin)

• Incorrect because the patient is already up-to-date with tetanus, eliminating the need for tetanus immunoglobulin. 1
• This option completely ignores the rabies risk, which is the primary concern with stray animal bites. 1, 2

Option C (Observe and Reassess After 48 Hours)

• Dangerous delay that could prove fatal. Rabies PEP should be initiated immediately, not delayed for observation. 1
• The 48-hour timeframe has no basis in rabies management guidelines. 1

Option D (Reassurance Without Treatment)

• Completely inappropriate and potentially lethal. The cat's apparent health is irrelevant—stray animals of unknown vaccination status must be presumed potentially rabid. 1, 2
• Even healthy-appearing animals can transmit rabies before showing clinical signs. 1

Critical Clinical Pitfalls to Avoid

Common errors in rabies PEP administration include:

• Failure to infiltrate RIG into the wound site (only 56% compliance in one study, despite 100% guideline recommendation). 6
• Administering RIG and vaccine in the same anatomical site, which can suppress antibody production. 1
• Using the gluteal area for vaccine administration. 1, 2
• Delaying treatment while attempting to locate or observe the animal. 1

The correct answer is B: Rabies vaccine and immunoglobulin, initiated immediately along with thorough wound care.