Lesson 10.6: Rabies II

1-3 Months

Average human rabies incubation period

5-10%

% of human rabies incubation period that lasts longer than one year

Virus Incoculated Amount, Exposure Severity, Exposure Location

# Factors that affect human rabies incubation period

Severity Exposure

Patients with multiple and/or deep penetrating bite wounds may have a shorter incubation period

Exposure Location

Patients with bite wounds in highly innervated areas and/or close to the central nervous system may have shorter incubation period

Myocytes

Where the rabies virus multiplies (May invade the nerve directly without multiplication)

Peripheral Nerve Cells

Penetrated by the rabies virus via viral uptake at neuronal endings

Central Nervous System

Where the rabies virus is transported to through the sensory & motor nerve fibers

Peripheral Tissues

Where the rabies virus spreads during viral dissemination in the CNS

Salivary Gland Infection

Allows further rabies transmission to other mammals

Prodromal Stage

Happens just before the virus enters the brain (Paresthesia)

Paresthesia

Paint at the bite site

Encephalitic Furious Rabies & Paralytic Rabies

2 Types of Acute Neurologic Stages

Encephalitic Furious Rabies

Phobic larynx, pharynx, neck muscle, & diaphragm spasms that can be triggered by hydrophobia/inspiration (Autonomic Hyperactivity & 80% )

Paralytic Rabies

Characterized by acute ascending paralysis (20%)

Species, Size, Health Ownership

Data for biting animals in concern of rabies transmission likelihood

Rabies Vaccination History

Necessary for determining the likelihood that it was

shedding rabies virus at the time of the bite

Younger Animals Present a greater rabies risk than older animals

Deposited Virus Amount

Proportional to the rabies risk transmission in vulnerable sites

Closer to the CNS

May lead to a shorter incubation period when it comes to the virus's distance

Face, Head, Neck, Spine

Where bites have a more exigent rabies risk & need for rabies prophylaxis

Hands, Fingers, Genitalia

Highly innervated tissues that provide a rich environment for the rabies virus to invade & replicate