Rabies

Objectives

After completing this article, the reader should be able to:

1. Explain the pathogenesis and epidemiology of rabies virus.

2. Describe the clinical manifestations of rabies.

3. Identify the most appropriate tests available to diagnose rabies infection.

4. Outline the specific measures to be taken after exposure to rabies.

5. Appreciate the strategies used to eradicate reservoirs of rabies virus in terrestrial wildlife.

Case Study

A previously healthy 13-year-old boy is admitted to the hospital with the chief complaints of altered mental status and unsteady gait. Five days prior to this admission, he developed low-grade fever, generalized body pain, dry cough, and listlessness. Over the course of the next few days, he developed abdominal pain and nausea. Two days prior to this admission, he was noted to be confused, have an unsteady gait, and have difficulty swallowing. He has no history of trauma, ingestion, or bites. His mother mentioned that he had fed a raccoon in his backyard 2 to 3 months ago. The raccoon later was found dead. On examination, the boy’s temperature is 100°F (37.8°C). He has fluctuating consciousness, hypersalivation, and hydrophobia. He has an ataxic gait and appears disoriented. The results of his cerebrospinal fluid (CSF) examination are: clear fluid with no red blood cells, 50 white blood cells/mm³, 70% lymphocytes, 20% monocytes, glucose of 41 mg/dL (2.3 mmol/L) (serum glucose of 90 mg/dL [5 mmol/L]), protein of 155 mg/dL, and no organisms on Gram stain. CSF bacterial culture exhibits no growth at 72 hours.

Introduction

The word “rabies” is derived from a Sanskrit word “rabhas” meaning “to do violence.” In Greek, “Lyssa” means “mad rage”; therefore, the genus of the virus that causes rabies is named Lyssavirus. The word hydrophobia means “fear of water” and is derived from two Greek words: hydor (water) and phobos (fear).

Rabies, an acute, progressive encephalitis usually …