R ABIES FACTS

1. RABIESEpidemiology Dr Venu ShahAssistant Professor, Community MedicineGCS Medical College, Ahmedabad

2. RABIES FACTS • Rabies is 100% fatal. • It is also 100% preventable. • It does not give a second chance.

3. Specific Objectives • Characteristics of the disease • Magnitude of Problem in the world • Magnitude of Problem in India • Clinical features of Disease • Epidemiology

4. RABIES • Epidemiology • Agent – Host – Environment • Reservoir of Infection • Source of Infection • Mode of Transmission • Development of disease • Incubation of disease

5. Rabies: Rabhas Disease as old as our civilization Paintings: Oriental physicians as far back as 3000 BC

6. What is Rabies? • Rabies has its origin in Sanskrit , ‘Rabhas’ means “to do violence” • An acute, highly fatal zoonotic disease of the CNS caused by Lyssavirus type 1. • Rabies virus infects the central nervous system, causing encephalopathy, paralysis, and ultimately death.

7. There is no viremia. • There is no natural immunity. • Vaccine is safe in pregnant women.

8. Rabies is one of the most successful viruses in the world, prevalent in wildlife. It can replicate in all warm blooded animals. The virus survives by causing the afflicted host to find another host for it.

9. Magnitude of Problem(World wide ) • Rabies is enzootic in animals in more than 100 countries with a population of > 3.3 bilion . • Worldwide- 55,000 annual deaths 99% in developing countries • Temperate zone - 0.01% human rabies

10. Rabies: World wide incidence Highest incidence is in the Indian Subcontinent. 6

11. High Incidence Rate - India, China, Nepal, Sri lanka, Bangladesh, Ethiopia, Brazil, Colombia, Ecuador, El salvador • More than 10 million people, mostly in Asia, receive post exposure vaccination against rabies each year.

12. India Rabies is reported from all statesexcept Lakshadweep and the Andaman & Nicobar Islands. • POPULATION OVER 1 BILLION • LAND AREA 3.28 MILLION SQ. KM. • SHARES BORDER WITH CHINA, PAKISTAN, BHUTAN, NEPAL, • MYANMAR AND BANGLADESH • 4 29 STATES AND 6 UTs • 5 RABIES ENDEMIC

13. Magnitude of Problem (In India) • In India 20,000 deaths annually, i.e. IR of rabies is 2 per 1,00,000 population per year. • 17.4 million animal bite cases annually. • almost 1.8 million people annually receive post exposure prophylaxis

14. India accounts for 36% of the Global and 65% of the Asian human rabies deaths. No age or sex predilections (higher incidence of animal bites and rabies deaths among children and adult males). 96% of human rabies cases are due to bites from Rabid dogs. Cases reported from all over the country round the year Rabies in India

15. “Rabies free” area • “Rabies free” area: defined as one in which no case of indigenously acquired rabies has occurred in man or any animal species for 2 years. • Water- natural barrier • Countries: Australia, Newzealand, Japan, Taiwan, Hong-kong, Cyprus, Malta,U.K., Finland, Norwey, Sweden, Antartica, Islands of Western Pacific, Maldives. • India:-Lakshadweep, Andaman, Nikobar.

16. New Initiatives XI Five Year Plan Pilot project on Prevention and control of human rabies 2008 - 2010 National Institute of Communicable Diseases Directorate of Health Services Ministry of Health & Family Welfare & Municipal corporations of Pilot Project Cities

17. Justification of the project • 100% fatal yet 100% preventable with timely & appropriate PET • All bite victims do not seek treatment • Numerous myths and practices prevent appropriate treatment • Knowledge of treating doctors needs updating

18. Objectives • Preventionof human deaths due to rabies. • Enhanceawarenessin general community • Developtrainedhealth manpower • Strengthendiagnosticfacilities • Strengthening surveillance and maintenance of continuous surveillance • Sensitizationof other sectors

19. Pilot Project Areas • Ahemdabad • Bangalore • Delhi • Pune • Madurai

20. AGENT • Lyssavirus type 1 – • virus classified in the Rhabdovirus family • Currently, this genus comprise seven genotype, type 1 of which represent the classic rabies virus. • 100-300 nm length and 75 nm diameter. • It is neurotropic virus. • It has phospholipid envelop on the outside.

21. Structure of Rabies Virus • Bullet Shaped. • Enveloped Virus. (Lipid envelope) • Measures 75 nm x 180 nm. • Numerous spikes present on the envelope, these are made up of glycoprotein. • Glycoprotein necessary for viral attachment & also induce protective antibodies. G protein Envelope (membrane bilayer) RNA M protein RNP

22. It is sensitive to heat (half life 4 hours at 40 .c & 35 second at 60. c ), UV radiation & lipid solvents. That’s the reason for washing the wound with soap & plenty of water. • highly resistant to cold and dryness. • virus remains stable for several days at 0-4 . C and indefinitely at (-) 70. C .

23. “Street virus” pathogenic to all mammals with long variable incubation period (20 – 60 d). virus recovering from naturally occurring cases of rabies called street virus. “ fix virus”- defined as one that has short, fixed and reproducible incubation period (4-6 days). Used for vaccine preparation.

24. Host • Although all age groups are susceptible, rabies is most common in children aged below 15 years, with 30-50% of post exposure prophylaxis given to them majority being males • All warm blooded animals are susceptible • Rabies in human beings are a dead end of infection. • victims 1-24 years • laboratory staff, veterinarians , dog handlers, hunters, naturalists face bigger risk of rabies than do general public

25. Host(Cont.) • Bites are more common in males than females. • Main biting animal is dog (91.5%), others are cats, cattle, goats, horses, mongoose, jackals. • Lower limb (56.2%), upper limb (21%) • Single rabid dog is capable of biting 60-100 humans and animals and can cover upto 40 kms in a short span of clinical illness.

26. Reservoirs Of Infection Rabies exist in 3 epidemiological forms • Urban rabies- • 99% of human cases in India. Transfer of infection from wild life to domestic dogs results in creation of the urban cycle which is maintained by the dogs .

27. 2. Wild life rabies (Sylvatic)- perpetuated by jackle, Fox, Hyena and other wild life carriers which are the Main reservoir & transmitters maintains the cycle amongst themselves & transmit the infection to dogs & domestic animal Man may occasionally contract rabies by intrusion into wild life cycle of rabies

28. 3.Bat rabies- In some Latin American countries the Vampire bat is an important host and vector . provide constant source of infection for animal & man. Thus enabling virus to persist in nature. humans are affected when they sleep outdoors rabies is transmitted between bats by aerosols/bites serological surveys indicate that some bats survive exposure to rabies virus

29. Reservoirs Of Infection Rabies is not found in the UK due to control measures such as quarantine of animals entering and departing the UK.

30. Animal Transmitting rabies in India • Domestic :- • Dogs & Cats • Wild :- • Foxes & Jackals • Monkeys • Mongoose • Bears Peridomestic :- • Cows & Buffaloes • Sheep & Goats • Pigs • Donkeys • Horses • Camels • Not reported :- • Bats* • Rodents* • Birds • Squirrel

31. All exposures in wild are considered as category III exposures. • Bite by Bats or Rodents do not ordinarily necessitate rabies vaccination. However, bites by Bats or rodents in unusual circumstances may be considered for vaccination in consultation with an expert in the field of rabies.

32. Source Of Infection • Saliva of rabid animals. • Virus can remain in the saliva of cat & dog for 5-6 days before the onset of clinical symptoms, during the course of illness till death. • Quantity of virus is variable

33. Carrier State • Serological survey have shown that anti rabies antibodies in a proportion of un vaccinated animals (18% dogs, 4% foxes) • For months/years virus may be isolated from saliva of dogs • further studies required .

34. Mode of transmission • Animal bites- most common. • Pre-requisite - saliva of biting animal must contain virus at the time of bite • Licks on abraded skin/mucosa • Scratches • Aerosols- only by bats & in laboratory • Person- Person- Rare. Corneal & organ transplant

35. Incubation Period • Average : 20 – 90 Days (6 days to 6 years) • Bites on the head or face - upto 1 month. • Bites on the extremities - upto 3 months. • More than 6 months in less than 1% • More severe the exposure, shorter the IP • No other CDs’s IP is so variable as in rabies & depends on so many factors.

36. Incubation Period (in man) • Depends on factors like – • biting animal (wild animal-shorter) • severity of bite • Site of bite-head, neck, face, upper extremities • No. of bite and amount of virus injected • protection provided by clothing, treatment undertaken.

37. DEVELOPMENT OF THE DISEASE. • PRODROMAL PERIOD : 2 – 10 Days. • ACUTE NEUROLOGICAL STAGE : 2-10 Days. • COMA : 0 – 14 Days. • DEATH

38. Pathogenesis Salivary glands & Other organs Brain Spinal cord Dorsal root ganglia Peripheral nerves Local treatment & RIG Multiplication locally (in the muscle fibres) Note: The virus is neurotropic and there is no viremia in rabies.

39. Clinical features in Humans • The first symptoms of rabies may be flu-like signs — malaise, fever, or headache, which may last for days with discomfort at the bite. (Prodromal) • Cerebral dysfunction, anxiety, confusion, agitation, progressing to delirium, hallucinations, and insomnia. Acute Onset of paralysis and death. Once clinical signs of rabies appear, the disease is nearly always fatal. (Paralytic)

40. Clinical features(Cont.) • The more common “furious” form of rabies will then go on to exhibit hyperexcitablity spasms and hydrophobia. • The “dumb” form of rabies shows an ascending paralysis, patients with this form will survive longer.

41. Clinical Features(cont.) • Rabies in man is called HYDROPHOBIA. • Hydrophobia is PATHOGNOMIC of RABIES. • Widespread excitation of sensory, motor, sympathetic and mental system

42. Guide for Post-Exposure Prophylaxis CategoryType of contactRecommended Post exposure prophylaxis I Touching or feeding of animals None, if reliable case history Licks on intact skin is available. II Nibbling of uncovered skinWound management,; Administer anti-rabies vaccine immediately Minor scratches or abrasions Convert post exposure prophylaxis to pre exposure prophylaxis if animal remainswithout bleeding. healthy throughout the observation period of 10 days or if animal is euthanized and found to be negative for Rabies by appropriate laboratory techniques.

43. Guide for Post-Exposure Prophylaxis (Contd…)

44. Symptoms in animals • Symptoms in animals progress through 3 phases: • Prodromal – change in “normal” behavior (ie wild animals lose fear of humans; fear of water; bats active by day; etc) • Acute or “Mad Dog” – very agitated, aggressive, foaming at the mouth • Paralytic – Paralysis usually beginning in hind legs and progressing forward, ending in death.

45. Year wise burden of Dog Bite Cases in Gujarat (Year 2005 to 2009)

46. YEAR & MONTH WISE REPORTED DOG BITE CASES IN GUJARAT (YEAR 2005 TO OCT 2009)

47. Dog Bite Cases Monthwise in AMC area from 2006 to2009 Avg.

48. District wise status of Dog-Bite Cases, Year 2009, Gujarat

49. Information Details about Hydrophobia (Rabies) Cases & Outcome.

50. YEARLY CONSUMPTION OF ARV