A brief discussion on Rabies and its pathogenesis, Etiology, Epidemiology, Clinical manifestation, diagnosis, treatment.

3. Presentation by
ORJI DAVID
5TH COURSE
6TH MED FACULTY
KHARKOV NATIONAL
MEDICAL UNIVERSITY

4. TOPICS OF DISCUSSION
1. ETIOLOGY
2. EPIDEMIOLOGY
3. PATHOGENESIS
4. CLINICAL MANIFESTATIONS
5. DIAGNOSIS & DIFFERENTIAL DIAGNOSIS
6. TREATMENT
7. PROGNOSIS
8. PREVENTION

5. ETIOLOGY1

6. • The rabies virus has a cylindrical
bullet-shaped morphology and is
the type species of the
Lyssavirus genus of the
Rhabdoviridae family. These
viruses are enveloped and have
a single stranded RNA genome
with negative-sense.
• The rabies virus genome
encodes five proteins:
nucleocapsid (N), matrix (M),
phosphoprotein (P), glycoprotein
(G) and an RNA polymerase (L)

7. EPIDEMIOLOGY2

8. SOURCE OF INFECTION:
Infected wild and domestic canines, skunks,
raccoons, mongooses; vampire, frugivorous and insectivorous
bats.

9. TRANSMISSION:
• Bite of a rabid animal/person
• Contact of saliva of infected
animal/person with open
wounds, scratches, abrasions
or mucous membrane
• Handling, skinning and
consumption of raw infected
meat and/or infected carcases
• Inhalation of aerosolized rabies
virus in caves containing
millions of bats
• Organ transplantation

10. • Almost all human deaths caused by rabies occur in Asia and
Africa. There are an estimated 55,000 human deaths annually
from rabies worldwide.
• India has the highest rate of human rabies in the world,
primarily because of stray dogs, an estimated 20,000 people
die every year from rabies in India. The second highest rate is
in Vietnam and the third in Thailand.
• Dog bites account for over 90% of rabid-related fatalities
worldwide.

11. PATHOGENESIS3

12. • The
incubation
period of
rabies is
usually 1 – 3
months but
can be as
short as 2
weeks or as
long as 2
years!

13. CLINICAL MANIFESTATIONS4

14. • The clinical manifestations of Rabies generally
progresses through three distinct stages and they are:
1. The Prodromal Stage (1 – 7 days)
2. The Acute neurologic Stage
- Encephalitic (80 %) ( 1 – 7 days)
- Paralytic (20 %) ( 2 – 10 days)
3. Coma/death ( 1 – 14 days )

15. PRODROMAL STAGE
• Fever
• Malaise
• Headache
• Nausea
• Vomiting
• Agitation
• Paresthesia
• Pruritus near site of exposure
• Pain

16. Acute Neurologic Stage
Encephalitic (furious)
• Fever
• Confusion
• Hallucinations
• Hyperactivity
• Pharyngeal spasms
(hydrophobia,
aerophobia)
• Seizures
• Hypersalivation
Paralytic
Paralytic rabies is
characterized by early and
prominent muscle
weakness, often beginning
in the bitten extremity and
spreading to produce
quadriparesis and facial
weakness

17. DIAGNOSIS
and
DIFFERENTIAL DIAGNOSIS
5

18. 1. Rabies Virus – specific antibodies
In a previously unimmunized patient, serum neutralizing antibodies to
rabies virus are diagnostic. Antibodies may be detected within a few days after
the onset of symptoms, but some patients die without detectable antibodies.
2. Reverse Transcription Polymerase Chain Reaction (RT-PCR)
Detection of rabies virus RNA by RT-PCR is highly sensitive and specific.
This technique can detect virus in fresh saliva samples, CSF, and tissue.
3. Direct Fluorescent Antibody (DFA) Testing
DFA testing with rabies antibodies conjugated to fluorescent dyes is
highly sensitive and specific and can be applied to brain tissue or skin
biopsies from the nape of the neck. In the latter samples, rabies virus
can be detected in cutaneous nerves at the base of hair follicles.

19. DIFFERENTIAL DIAGNOSIS
• Rabies Hysteria
• Encephalitis of other viral origins
• Tetanus
• Post - vaccinal Encephalomyelitis
• Guillain – Barre syndrome

20. TREATMENT6

21. • Unfortunately, there are no established treatments for rabies
currently.
• Palliative therapy may be appropriate for some patients

22. PROGNOSIS7

23. • Rabies is an almost uniformly fatal disease ( ~ 100% fatality)
• Prognosis is improved if appropriate post exposure therapy
is given to patient during incubation period.
• Prognosis is worse after appearance of clinical symptoms
• There are only 6 well-documented cases of of survival after
symptomatic rabies infection and 2 of these patients died
few years later from marked post-infection neurological
sequelae.

24. PREVENTION8

25. Pre-exposure Rabies Vaccination
• Considered for people with occupational or recreational
risk of rabies exposures, including travelers to rabies
endemic areas.
• The primary schedule consist of 3 doses of rabies
vaccine given on days 0, 7, 21/28
• If a previously immunized individual is exposed to
rabies, 2 booster doses should be administered on
days 0 and 3.

26. Algorithm of Post - exposure Prophylaxis
Red = Yes
Blue = NoDid the animal bite the patient
or did saliva contaminate a
scratch, abrasion, open wound
or mucuos membrane?
Is rabies known or suspected
to be present in the species
and the geographic area?
Was the animal captured?
Was the animal behaving normally?
Does laboratory examination of
the brain by fluorescent Antibody
staining confirm rabies?
Rabies Immunoglobulin and vaccine
Does the animal
become ill under
observation over
the next 10 days
No PEP

27. A dog is the only thing on earth
that loves you more than you love
yourself.

28. THANK YOU !
SHUKRAAN!
СПАСИБО!
DANKE!