Report by: Norvin L. Adlawan

RABIES

• a ZOONOTIC DISEASE (a disease that is

transmitted from animals to humans) that

is caused by the

RABIES

Rabies Virus

Source: WHO

THE RABIES VIRUS

Rabies virus belongs to the order Mononegavirales, viruses with a nonsegmented, negative-stranded RNA genomes. Within this group, viruses with a distinct "bullet" shape are classified in the Rhabdoviridae family. The genus Lyssavirus includes rabies virus, Lagos bat, Mokola virus, Duvenhage virus, European bat virus 1 & 2 and Australian bat virus.

Source: Center for Disease Control & Prevention

MAIN HOSTS

DOGS

1 Dogs are the main host and transmitter of rabies. They are the source of infection in all of the estimated 55,000 human rabies deaths annually in Asia and Africa.

BATS

2 Bats are the source of most human rabies deaths in the United States of America and Canada. Bat rabies has also recently emerged as a public health threat in Australia, Latin America and western Europe.

CATS & OTHERS

3 Cats are the most common domestic animals with rabies in the United States.

Almost any wild or domestic animal can potentially get rabies, but it is very rare in small rodents (rats, squirrels, chipmunks) and lagomorphs (rabbits and hares).

TRANSMISSION

You can get rabies only by coming in contact with:

• Saliva

• Brain/Nervous Tissue

Source: Center for Disease Control & Prevention

TYPE OF EXPOSURE

Templates

1

BITE

1 Any penetration of the skin by teeth constitutes a bite exposure. All bites, regardless of body site, represent a potential risk of rabies transmission, but that risk varies with the species of biting animal, the anatomic site of the bite, and the severity of the wound.

NON-BITE

The contamination of open wounds, abrasions, mucous membranes, or theoretically, scratches (potentially contaminated with infectious material from a rabid animal) constitutes a nonbite exposure.

2

• The incubation period for rabies is typically

1–3 months, but may vary from less than 1

week to more than 1 year.

INCUBATION PERIOD

• Fever

• Pain or an unusual or unexplained tingling,

pricking or burning sensation (paresthesia)

at the wound site.

INITIAL SYMPTOMS

FORMS OF THE DISEASE

Templates

1

CLASSIC RABIES

People with classic (furious) rabies exhibit signs of hyperactivity, excited behaviour, hydrophobia and sometimes aerophobia. After a few days, death occurs by cardio-respiratory arrest.

PARALYTIC RABIES

A rarer form of rabies, paralytic rabies, has been linked to vampire bats. This form of rabies runs a less dramatic and usually longer course than the furious form. The muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs.

PATHOPYSIOLOGY

1

RABIES VIRUS

Entry into break in skin(bites, abrasions, mucusa)

Incubation Period (1 month – more

than 1 year)

Invasion Phase

Pain Fever Malaise Anorexia Headache

Sore Throat

Increased Sensitivity

Excitement Phase

Imminent thoracho-lumbar involvement (PNS): Pupillary dilatation, Lacrimation

Increased thick saliva/foaming of the mouth. Excessive sweat

Anxiety and fear Hydrophobia Mania and hallucinations

with lucid intervals Pronounced muscular

stimulation and general tremor

ConvulsionsNext Slide…

Templates

1

DEATH

COMA

Gradual weakness of muscle groups; muscle spasms cease, ocular palsy, vertigo

(+) Babinski (lesions at pyramidal tract)

HR shifting from tachycardia (100-120) to bradycardia (40-60)

Cheyne-Stokes breathing Local sensation diminished (pain,

heat, cold) Bladder and intestinal retention

(damage to the innervation of the musculature of bladder and intestine

Hydrophobia disappear Slight difficulty wallowing Ascending paralysis, flaccid

paralysis of extremities until it reaches respiratory muscles

Apathy, Stupor

PARALYTIC PHASE

(Depression Phase)

Continuation…

• Several tests are necessary to diagnose rabies ante-mortem (before

death) in humans; no single test is sufficient.

• Tests are performed on samples of saliva, serum, spinal fluid, and

skin biopsies of hair follicles at the nape of the neck.

• Reverse transcription polymerase chain reaction (RT-PCR).

• Serum and spinal fluid are tested for antibodies to rabies virus.

• Skin biopsy specimens are examined for rabies antigen in the

cutaneous nerves at the base of hair follicles.

DIAGNOSTIC EXAMS

• Responsible pet ownership (Immunization)

• Thoroughly clean ALL BITES AND SCRATCHES made by animal

with strong medicinal soap or solution

• Report immediately rabid or suggestive of rabies domestic or wild

animals to proper authorities

• Pre-exposure to high-risk individuals

PREVENTION

• If dog is apparently healthy, observe the dog for 14 days. If it dies or

shows signs suggestive of rabies, consult a physician

• If the dog shows signs suggestive of rabies, kill the dog immediately

and bring head for lab exam. Submit for immunization while awaiting

for results

• If the dog is not available for observation (killed, died, or stray)

submit for immunization

DOH PROTOCOLS

POST-EXPOSURE PROPHYLAXIS

CATEGORY I: touching or feeding animals, licks on intact skin.

POST-EXPORSURE MEASURES: None

CATEGORY II: nibbling of uncovered skin, minor scratches or abrasions without bleeding.

POST-EXPOSURE MEASURES: Immediate vaccination and local treatment of the wound

Category III: single or multiple transdermal bites or scratches, licks on broken skin; contamination of mucous membrane with saliva from licks, exposures to bats.

POST-EXPOSURE MEASURES: Immediate vaccination and administration of rabies immunoglobulin; local treatment of the wound

• Local wound treatment. Wash with soap and water. Use iodine or

other disinfectants

• Antibiotics and Anti-tetanus as prescribed by Physician

• Rabies-specific treatment. Active immunization (Human Diploid Cell

Rabies Vaccine) and passive immunization (Rabies Immune

Globulin)

MEDICAL INTERVENTIONS

THANK YOU!

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