Clinical features

If rabies is suspected, clinicians should immediately contact public health authorities and the relevant reference laboratory for advice (1)

The incubation period of this disease is variable and may range from a few weeks to several years depending on the animal, viral inoculums, and location of the bite.

• on average, the incubation period is 1 to 3 months
• majority of cases present within the first two months after inoculation
• generally, bites on the head, face and neck have a shorter incubation period than those elsewhere.

No clinical signs are characteristic of rabies

• prodromal symptoms may mimic systemic viral infections – malaise, fever, anorexia, nausea
• patients may also experience neuropathic pain at the site of the bite or weakness of the affected limb
• intense pruritus, beginning at the site of the bite which later progresses to involve the limb or side of the face, and myoedema, a mounding of the muscle elicited by being struck with a reflex hammer and that resolves within seconds may suggest rabies

Acute neurological phase follows 2-10 days after the prodromal symptoms where the virus manifests itself in the central nervous system.

• there are two distinct clinical varieties in patients presenting with an acute neurological syndrome
  • furious rabies - also known as classical rabies
  • dumb rabies - the paralytic variety
• progression towards coma and death occurs within one to two weeks from the onset of neurological dysfunction

Other manifestation such as tremor, myoclonus, and cranial nerve, motor, or sensory deficits have been reported specially in patients with bat related rabies (1).

Reference:

• (1) Crowcroft NS, Thampi N.The prevention and management of rabies. BMJ. 2015;350:g7827.