Incubation: Several days – 19 yrs
Avg: First 90d (75%)
< 30d (25%)
30 – 90d (50%)
90d – 12mo. (20%)
> 1yr (5%)


Initial Symptoms:
Systemic: As with other viral infections: Fever
(4 – 10 days) H/A
Upper respiratory/GI sx’s
Myoedema (mounding of part of muscle after
reflex hammer strike, extincting in seconds)


Neuro: Personality/Cognitive Changes
Pain/Paresthesias – exposure site
2 – 14 days to coma
“Furious” Rabies (80% of cases): Hydrophobia
Hydrophobia: exaggerated irritant reflex of the respiratory tract (? Nucleus ambiguous)
Description by Sir William Gowers (excerpts),
Discomfort about throat
Choking sensation
Liquid dysphagia (pharynx spasm spreading to muscles)
Short, quick inspiration; a “catch in the breath”
Strong inspiratory effort with accessory respiratory muscles and mouth
angles outward and shoulders raised
Increasing respiratory/pharynx spasm severity and sensitivity (to provoke);
brought on by mere water contact on lips or a draught of air on hyperesthetic skin
Inability to swallow saliva, abundant and viscid (hanging on mouth)
Vomiting common
Attacks very distressing to patient – increasing attacks, such that even
sight of water causes attack
Strong light or visual image (mirror reflection) provoking attacks
Sufferer’s horror/dread of attack becomes intense
Disordered swallowing causes mental disturbance and other extensive
muscle spasms
Spasms first only with muscles of deglutition and respiration, then to other
muscles and finally spasmodic paroxysms (convulsive) at first respiratory,
then general (tetanoid rigidity/opisthotonus)
Delusions/Wild Delirium – mental derangement, worst during paroxysms,
and frenzied patient spits saliva at others and attempts to bite; strange
dog-like barking
Other Episodic Neuro Phenomena: Hyperactivity
Hyperventilation, then periodic/ataxic
breathing, then apnea
SIADH (Syndrome of Inappropriate Anti Diuretic Hormone)
Other: Cardiac arrhythmias
Autonomic dysfunction
– piloerection
– sweats
– pupillary dysfunction
– increased salivation
– priapism/ejaculation
Death:   Within 1-2 weeks of coma FR, with strong medical support, passes through PR phase


Paralytic(Dumb) Rabies (PR)
– No hydrophobia, aerophobia, hyperactivity, or seizures
Initial: Ascending paralysis (like Guillain-Barré syndrome) or symmetric quadriparesis
Weakness may be most severe in bitten limb.
Later: Meningeal signs (sometimes prominent)
Death usually due to myocarditis with arrhythmias or CHF
Total time to death from illness onset averages 0 – 14 days