Morphology: Enveloped, single-stranded negative-sense RNA virus. Family Rhabdoviridae, genus Lyssavirus. Bullet-shaped virion. Neurotropic — travels retrograde via peripheral nerves to CNS. Reservoir varies geographically: bats (US), dogs (worldwide), raccoons + skunks + foxes (US wildlife).
Typical drugs
—
Empiric therapy when resistant
Post-exposure prophylaxis (PEP) is the only effective intervention — vaccine + rabies immune globulin (HRIG, weight-based, infiltrated around wound). Once symptoms develop, rabies is essentially 100% fatal despite all interventions (Milwaukee Protocol has rare survivors but is investigational).
Resistance notes
N/A — no antiviral therapy.
Pearls
ALWAYS rabies PEP for (1) wild carnivore (raccoon, skunk, fox, coyote) bite, (2) bat exposure (even questionable contact during sleep), (3) dog/cat bite in rabies-endemic area + animal not available for observation. Domestic dog/cat in US: observe animal × 10 days; if healthy, no PEP needed. PEP regimen (previously unvaccinated): HRIG 20 IU/kg (infiltrate around wound, give remainder IM at distant site) + rabies vaccine 4-dose series (days 0, 3, 7, 14; immunocompromised get 5th dose day 28). Pre-exposure prophylaxis for veterinarians, lab workers, travelers to endemic areas: 2-dose series (days 0, 7); if exposed later, just 2 booster doses (no HRIG). Symptoms = encephalitic (furious) form or paralytic (dumb) form; hydrophobia + aerophobia + agitation + autonomic instability → coma → death. Survivors of symptomatic rabies are exceedingly rare.
References
- CDC Rabies Clinical Guidance
- ACIP Rabies Prevention (2022)