What is the recommended post-exposure prophylaxis (PEP) for a patient of any age with any medical history bitten by a bandicoot rat, considering rabies vaccine and potential previous rabies vaccination?

Rabies Post-Exposure Prophylaxis for Bandicoot Rat Bite

For a bandicoot rat bite, rabies post-exposure prophylaxis (PEP) should generally NOT be initiated unless the rat is confirmed rabid or rabies is highly endemic in your region with documented rat transmission—consult local public health authorities immediately to determine if PEP is indicated, as rodent bites almost never require rabies prophylaxis. 1, 2

Risk Assessment for Rodent Bites

• Rodent bites, including from bandicoot rats, almost never require rabies PEP because small and large rodents (including rats, mice, squirrels, hamsters, guinea pigs, gerbils, chipmunks, rabbits, hares, woodchucks, and beavers) are not significant rabies vectors. 1, 2

• Local and state public health officials must be consulted to assess the specific risk in your geographic area, as rabies presence varies by region and animal species. 1, 2

• The decision depends on whether rabies has been documented in rodents in your specific region and whether the animal can be tested. 1, 2

Immediate Wound Management (Regardless of PEP Decision)

• Immediately wash all bite wounds thoroughly with soap and water for 15 minutes—this is the single most effective measure for preventing rabies infection and markedly reduces the likelihood of rabies in animal studies. 3, 4, 5, 6

• Follow wound cleansing with irrigation using a virucidal agent such as povidone-iodine solution if available. 3, 5, 6

• Administer tetanus prophylaxis as indicated. 3, 6

• Consider antibiotic prophylaxis based on wound characteristics, location, and time since bite. 3

• Avoid suturing wounds when possible, as this may increase infection risk. 3

If PEP Is Indicated (After Consultation with Public Health)

For Previously Unvaccinated Persons

Administer both human rabies immune globulin (HRIG) and a 4-dose vaccine series:

• HRIG dose: 20 IU/kg body weight, given once on day 0. 3, 4, 5, 6, 1

• Infiltrate the full calculated HRIG dose around and into the wound(s) if anatomically feasible; inject any remaining volume intramuscularly at a site distant from vaccine administration. 3, 4, 5, 6

• HRIG can be administered up to and including day 7 after the first vaccine dose if not given initially, but is not indicated beyond day 7. 3, 4, 5

• Never administer HRIG in the same syringe or anatomical site as the vaccine. 3, 4, 5

• Do not exceed the 20 IU/kg dose, as higher doses suppress active antibody production. 3, 4, 5

Vaccine regimen:

• Administer 4 doses of 1.0 mL each of human diploid cell vaccine (HDCV) or purified chick embryo cell vaccine (PCECV) intramuscularly on days 0,3,7, and 14. 4, 5, 6, 1, 7

• Inject in the deltoid muscle for adults and older children; use the anterolateral thigh for young children. 4, 5, 6, 1

• Never use the gluteal area for vaccine administration—this produces inadequate antibody response and is associated with vaccine failure. 4, 5, 6, 1

For Previously Vaccinated Persons

• Administer only 2 doses of vaccine (1.0 mL each) on days 0 and 3. 3, 4, 5, 6, 1

• Do NOT administer HRIG, as it will inhibit the anamnestic immune response. 3, 4, 5, 6

• This applies to persons who have completed a recommended pre-exposure or post-exposure vaccination regimen with a cell culture vaccine or who have documented rabies virus neutralizing antibody titer. 3, 1

For Immunocompromised Patients

• Administer a 5-dose vaccine regimen on days 0,3,7,14, and 28 plus HRIG at 20 IU/kg on day 0, even if previously vaccinated. 4, 5, 6

• Immunosuppressive agents (corticosteroids, antimalarials, chemotherapy) and immunosuppressive illnesses (HIV, chronic lymphoproliferative leukemia) substantially reduce vaccine response. 4

• Serologic testing for rabies virus-neutralizing antibody is mandatory 1-2 weeks after the final dose to confirm adequate response (≥1:5 dilution by RFFIT). 4, 1

• If no acceptable antibody response is detected, manage in consultation with the patient's physician and public health officials. 4, 1

Critical Pitfalls to Avoid

• Do not delay wound cleansing—it is the most crucial first step and should be performed immediately. 3, 4, 5, 6

• Do not assume rodent bites require PEP without consulting public health authorities—this is a critical decision point specific to your region. 1, 2

• Do not administer vaccine in the gluteal area—this results in inadequate immune response. 4, 5, 6, 1

• Do not give HRIG to previously vaccinated persons—it suppresses the immune response. 3, 4, 5, 6

• Do not exceed 20 IU/kg HRIG dose—higher doses suppress active antibody production. 3, 4, 5

• Do not use the standard 4-dose regimen for immunocompromised patients—they require the 5-dose schedule. 4, 5, 6

Timing Considerations

• PEP should be initiated as soon as possible after exposure, ideally within 24 hours, though treatment remains indicated even if weeks or months have elapsed since exposure. 4, 5

• Rabies is nearly 100% fatal once clinical symptoms develop, making prompt treatment essential. 4, 5, 6

• If PEP is initiated and laboratory testing confirms the animal was not rabid, prophylaxis can be discontinued. 3, 1