Rabies Management Module 1

Rabies

The oldest and most feared zoonotic diseases due to the almost sure outcome of death

Zoonotic

Diseases are those of animal origin that are transmissible to humans

Rabies

Seen in more than 150 countries, causing 59,000 deaths per year worldwide

Asia and Africa

What countries have most cases of rabies?

Lyssavirus species

Rabies is caused by the rabies virus called?

Rhabdoviridae

What family is lyssavirus species belong?

Dogs

Human rabies cases are most commonly caused by?

99%

How many percentage is the contribution of dogs to all transmission to humans?

Encephalomyelitis

Once rabid animal, most commonly dogs, passes the virus on to humans through its saliva via bites and scratches. It causes acute, progressive, and almost fatal?

40%

How many percent globally of animal bite patients are children under age of 15 y/o

True

True or False

The rabies virus is transmitted via saliva from an infected animal that affects the brain or nervous system

True

True or False

Petting and handling animal or contact with bodily fluids other than saliva brain tissue (such as blood, urine, or feces) does not cause an exposure to rabies

Direct and Indirect

Two types of human to human transmission

Direct

Types of human to human transmission through bite or contact with saliva and other bodily fluids of an infected person

Indirect

Types of human to human transmission via organ transplant

Indigenous

Rabies is classified as this by being naturally existing in a specific location, rather than being imported from another province or country

Dog vaccination

Education on animal bite prevention

Proper wound care

Pre exposure prophylaxis

Ways to prevent rabies

Dog vaccination

Most cost effective strategy to prevent transmission to humans. This is thought in the community as being part of responsible pet ownership

Education on animal bite prevention

This is essential in bringing down rabies cases worldwide. Involves learning about dog behavior and how to avoid being bitten

Proper wound care

Using soap and water, this may reduce the risk of rabies as much as 40%

Pre exposure prophylaxis

It helps decreasing the number of rabies cases. It is given in the Philippines to person who may be high risk in rabies exposure such as animal workers or vaccinators, animal caretakers, or pet owners

September 28

World Rabies Day is celebrated when?

March of every year

Rabies month?

Louis Pasteur

The French chemist, and microbiologist who developed the first rabies vaccine in 1885

Food and Agricultural Organization

Global alliances for Rabies Control

World Organization for Animal Health

World Health Organization

Zero by 30 strategy involves who?

Incubation

Prodrome

Acute Neurologic Phase

Coma and Death

Stages of Rabies Disease

Exposure

This is commonly through bite or scratch from the infected animal usually by dog, that accounts for 99% of rabies cases

Saliva of rabid animal

The virus is transmitted through the?

Incubation

The rabies virus is replicated in the muscle at the bite site.

Incubation

The average period from the time of exposure until time of patient develops symptoms is 20-90 days also ranges from 2 weeks to 6 years

Incubation

Once the virus reaches the muscle, it binds to nicotinic acetylcholine receptors on postsynaptic membranes at neuromuscular joints. These receptors mediate neuromuscular transmission are found throughout the nervous system

Incubation

The virus then travels via retrograde transport along the peripheral nervous system at speed of 250 mm/day

Incubation

In this period the virus varies depending on the

1. Infecting Rabies strains

2. The size of the inoculum in the biting animal’s saliva

3. The degree of innervation of the bite site

4. The proximity of bite site to the central nervous system

Incubation

Rabies post exposure prophylaxis is only effective during this phase of the disease. Once the patient enters the acute neurologic phase, PEP will not halt the progression of the disease

Prodrome

Rabies virus replicates in the dorsal ganglion and travels along the CNS. It is during this time that the patient experiences mostly non specific symptoms such as malaise, fever, fatigue, anorexia, fever, or even pain or itching in the bite site

Prodrome

The symptoms of this stage can last between 2-10 days

Acute Neurologic Phase

The rabies virus infects the brain and typically lasts from 2-7 days. It may present in two ways furious and dumb rabies

Furious or Encephalitic rabies

Classical and more common presentation of disease in acute neurologic phase. 80%

Dumb or paralytic rabies

Which occur 20% of human rabies cases. One of the type in acute neurologic phase

Furious or Encephalitic rabies

1. Phobic spasms in responsible to tactile, auditory, visual, or olfactory (Aerophobia, hydrophobia)

2. Automatic dysfunction (hypersalivation, cardiac dysrhythmia , gooseflesh, priapism)

3. Spontaneous inspiratory spams

4. Restlessness, aggression, hallucinations, disorientation, bizarre behavior, agitation, confusions, signs of ANS dysfunction

5. Alternating with periods of lucidity

6. Seizures

Dumb or paralytic rabies

1. Lack of aggression

2. Weakness

3. Phobic spams - 50%

4. Aerophobia and hydrophobia may be absent

5. Myoedema at percussion sites

6. Sphincter involvement common

7. Can be mistaken for GBS

8. Generally survive a few days longer

Hydrophobia

Aerophobia

Pathognomonic signs of rabies

Louis Pasteur

In 1885, he developed a crude nerve tissue vaccine for the post exposure treatment of rabies

Joseph Meister

The first patient successfully treated using the vaccine made by Pasteur

True

True or False

The nerve tissue vaccines were eventually phased out as they were poorly efficacious and were reactogenic. They also required high number of doses. There were also a risk of severe and even fatal encephalitis and polyneuritis

Foaming at the mouth

Hypersalivation and pharyngeal dysfunction that occurs in rabies cause the classic appearance of patient ?

Coma and Death

The outcome of rabies is sure and certain after neurologic phase. This usually occurs about 4-10 days from the onset of symptoms. Patients succumb from respiratory, cardiovascular, neurologic, and pituitary complications (multiple organ failure)