Rabies

1. RABIES
Dr Pallavi Potdar
Associate Prof.,
Community Medicine
D.Y. Patil Medical College Kolhapur

2. Classification-
1) Anthropozoonosis –
2) Zooanthroponosis-
3) Amphixenosis-
ZOONOTIC DISEASES

3. 4 categoriesof zoonosis-
 Direct zoonosis- direct contact
contact with fomite
mechanical vector
e.g rabies, brucellosis
 Cyclo-zoonosis- more than 1 vertebrate host
no invertebrate host
e.g taeniasis,echinococcosis

4. Categories ..
 Meta-zoonosis- invertebrate vectors
vertebrate vector
e.g plague, schistosomiasis
 Sapro- zoonosis- vertebrate host + non-animal site
e.g larva migrants

5. RABIES

6. Epidemiology
 Magnitude of the problem :
 Approximately 55,000 people die from rabies each
year
 majority of these deaths occurring in Asia and
Africa.
 In Africa, there are estimated at 24,000 (or 4 per
1,00,000 population) deaths annually.

7.  In India alone, 20,000 deaths are estimated to
occur annually, i.e. 2 per 1,00,000 population
 Rabies free areas ?

8. Agent
 : Lyssavirus type 1
 Rhabdoviridae family.
 This RNA virus is bullet shaped
 100 - 300 nm in length and 75 nm in diameter.
 lipid envelope , spike like projections.

9. RabiesVirus

10. Electron MicroscopeView
Negatively Stained RabiesVirus

11. Reservoirof infection
 Urban- dogs & cats
 Wild-life ( sylvatic)- jackal,fox
 Bat rabies- vampire bats

12. Sourceof infection
 Saliva of rabid animals
 4-6 days before onset of symptoms till death of
animal
 virus-Not in all rabid animals saliva

13. Carrier
 Dogs

14. Host
 all age groups are susceptible
 most common in children aged below 15 years
 High risk group-

15. Incubation period
 Man-
 four days to as long as 19 years.
 The usual duration is between 20 to 90 days.
 95% cases have incubation period less than one
year.
 Factors affecting -

16. Transmission
Animal bites-
Licks- on abraded skin/ mucosa
Aerosols – bats/labs
Person –person- corneal/organ transplant

17. Transmission
 Almost all
transmission is by bite
 50 times greater risk
than a scratch
 Pathogenesis

18. Animal Behavior
 Classic Picture of rabid,
dog foaming at the
mouth…
 aggressive behavior, ataxia,
irritability, anorexia,
lethargy or excessive
salivation.

19. clinical features in man
 Prodromal stage -3-5 days
 Sensory-
 Motor- muscle spasms
 Sympathetic-salivation,perspiration
 Mental system-
 hydrophobia

21. Rabies in man
 Diagnosis-
 Ag detection –immunofluorescence of skin
biopsy
 Virus isolation
 Treatment

22. Preventionand Control
 Rabies Vaccines
1)Nerve Tissue Vaccine (NTV)
2) Duck embryo vaccine (DEV)
3)Cell culture vaccine
a) human diploid cell vaccine(HDC)
b)tissue culture –animal cell vaccine

23.  HDC- human diploid fibroblast cells
 Safe, highly potent
 Animal vaccines- chick embryo fibroblast, dog
kidney cells

24. Prevention of human rabies
 Post-exposure prophylaxis
 Pre-
 Post-exposure Rx of patients previously
vaccinated.

26. Post-exposureprophylaxis
 Local treatment of wound-
cleansing
savlon, cetavlon ?
suturing ?
anti-rabies serum
antibiotics & TT
observe animal for 10 days

27. Indications foranti-rabies treatment
 Animal shows signs /dies within 10 days
 Biting animal cant be traced
 Unprovoked bites
 Lab tests- FRA, Negri bodies
 All bites by wild animals

28. Postexposure prophylaxis
schedule
Route/day of
administration
D0 D3 D7 D14 D21 D28 D90
Essen ( im)
1 1 1 1 - 1 +/_*
Zagreb ( im) 2 - 1 - 1 - -
Oxford ( intra-
dermal)
8 - 4 - - 1 1
2 site 2 2 2 - - 1 1

29. Rabies Immunoglobulin (RIG)
 equine (ERIG) -40 IU/ kg
 human (HRIG) -20 IU/ kg
 all category III exposures and
 in category II exposures involving immunodeficient
individuals.

30. RIG..
 infiltrated into and around the wounds.
 The remainder should be administered by deep
intramuscular injection at an injection site distant
from the vaccine injection site.
 In case of multiple wounds, the RIG should be
diluted with normal saline to make sufficient
volume to ensure infiltration at all wound sites

31. Pre- exposure prophylaxis
 1 ml im/ 0.1 ml id
 O , 7 , 28
 Booster injections every 2 yrs

32. Postexposure Rx of previouslyvaccinated
 0, 3 ,7

33. Rabies in Dogs
 Incubation period- 3-8 wks
 2 forms-
 Furious rabies
 Dumb rabies
 Lab –
 Vaccination of dogs-

34. Control of urban rabies
 Registration & licensing of all domestic dogs
 Immediate destruction of dogs bitten by rabid
animal
 Imported dogs- quarantine -6 mths
 Health education
 Oral vaccine?

35. How toavoid dog bites.
 Never disturb a dog who is…..
 Eating
 Sleeping
 Caring for puppies
 Do not …..
 Look a dog straight in the eye
 Throw anything at a dog
 Run near dogs

36. How toavoid dog bites.
 If a growling dog comes near you…..
 ….stand still with your arms down, pretend you
are a tree.

37. How toavoid dog bites.
 If a dog attacks you….
 ….. curl into a ball and protect your face, pretend
you are a rock.