1.RABIES PREVENTION AND CONTROL 1Anukrati Shukla

2. Rabiesis an acute, progressive encephalomyelitis The case fatality rate is the highest of any infectious disease One of the oldest described diseases The leading viral zoonoses of global public health significance2 3. Rabies is caused by RNA viruses in the family Rhabdoviridae, genus Lyssavirus The type species of the genus is Rabies Virus 3 4. Allwarm-blooded vertebrates are susceptible to infection Mammalsare the natural hosts of rabies Reservoirsconsist of the Carnivora (canids, skunks, racoons, mongoose, etc.) and Chiroptera (bats) 4 5. Virusis transmitted via bite Agents are highly neurotropic Enter peripheral nerves Centripetal travel by retrograde flow in axoplasm of nerves to CNS Replicate in brain Centrifugal flow to innervated organs, including the portal of exit, the salivary glands Viral excretion in saliva 5 6. Infectedanimal saliva inoculated by bite orscratch Infected saliva: contact with mucous membrane, transdermal exposure Virus shed in the saliva during, before or after clinical symptoms Human-Human: few reported cases following corneal transplantation Aerosol transmission: caves containing bats, lab work accident 6 7. 41. 2. 3.4.phases of illness Asymptomatic Prodromal Neurologic signs Coma7 8. Virus Incubation period: 3 to 8 weeks (4d-19yr) Firstphase: asymptomatic Second (prodromal) phase 2-10days Viral invasion of CNS (limbic system, spinal cord, brain stem) Headache Malaise Sore throat Behavioral & emotional symptoms Local pain itching, numbness (80%)8 9. Third phase: neurologic signs Widespread infection of the brain Furious : Hyperactive form Aggressiveness, biting, yelling, hallucinating Triggered by sensory stimuli Hydrophobia Aerophobia Violent diaphragmatic contractions Hyper-reflexia Lacrimation, salivation, mydriasis, pyrexiaParalytic form: 20% of patients Flaccid paralysis and paresis Mimics GBS, transverse myelitis Inflammation is more extensive and severe Spinal cord markedly involved 9 10. Fever Nuchalrigidity Paresthesia Fasiculations Convulsions Hypersalivation Hyperventilation10 11. Fourthphase: Coma Extensive cortical virus spread Death usually in 7 days Respiratory arrest Myocarditis Supportive care: sedation and analgesia11 12. Clinical Laboratory Postmortemdiagnosis in animals Intravitam diagnosis in humans Molecular techniques12 13. MRI:abnormal, ill defined, increased signal intensity on T-2 images Areas involved: brainstem, hippocampi, hypothalami, deep & subcortical white and grey matter13 14. Antigendetection(FA technique):gold standard Virus isolation Molecular techniques14 15. Viralculture: skin biopsy of the hair follicles at nape of the neck,saliva, CSF, urine, respiratory secretions (Culture in mice or in mouse neuroblastoma cell line ) Brain tissue: culture, histology for Negri bodies: yield low Immunostain (higher yield)15 16. Antigen detection:FA test on skin biopsies Antibody titration: in serum or CSF (RFFITorFAVN) Serology positive in serum in 8 days of symptoms Rabies antibodies infrequently found in CSF. Rabies vaccine does not cause positive CSF antibodies Molecular studies, monoclonal antibodies in epidemiologic studies Virus isolation:neuroblastoma cells or intracranial inoculation of mice. 16 17. A neuron from a formalin-fixed section of a brain from a patient with rabies, showing reddish-brown viral inclusions in the cytoplasm. Processed by immunohistochemistry. 17 18. Immunofluorescent viral inclusions in a peripheral nerve in a cryostat section from a patient with rabies, obtained via an antemortem nuchal skin biopsy. 18 19. Tetanus Gullianebarre syndrome NTV side effect Meningitis/encephalitis Epilepsy Drug toxicity19 20. PVStrain(pasteur virus) PV12 strain PM strain(pitman moore strain) CVS strain(challenge virus strain) LEP Flury chick embryo HEP ERA (evelyn rokitinki abelseth)strain of SAD (street alabama dufferin)virus 20 21. Human a) b) a) b) c) d) e)Cell culture vaccine(HDCV,PCECV,PVCV) Purified egg vaccine Animal Modified live virus(oral and injectable) Cell-culture vaccines(inj) Nerve tissue vaccines(inj) Combined(inj) Recombinant(oral) 21 22. Humanrabies immunoglobulin: 20IU/dose(max=1500IU) Equinerabies immunoglobulin: 40IU/dose(max=3000IU) Highlypurified F(ab)2 products from ERIG 40IU/dose(max=3000IU)22 23. Pre-exposure Post-exposure23 24. Pre-exposure prophylaxis: vaccination of people in high risk groups: Veterinarians Animal handlers Certain lab workers Pre-exposure prophylaxis: intramuscular, 1ml (3 doses) or intradermal 0.1ml: at 0, 7, 21/28 days Antibodies usually persist for 2 yrs Repeat titres every 6-24 months depending on level of exposure Acceptable titre levels are 0.5 IU/ml . 24 25. FACTORS GUIDING TREATMENT Nature of contact or injury Area Availability of animal for lab exam Species of animal Clinical status of animal Vaccination history of animal25 26. CategoryContactManagement1Touching,feeding of animals Licks on intact skinnone2Nibbling of uncovered skin Minor scratches or abrasions without bleedingVaccine immdiately3Single or multiple transdermal bites or scratches, licks on broken skin Contamination of mucous membrane with saliva Exposure to batsRabies immunoglobulin and vaccineStop treatment if animal remains healthy throughout 10days or if animal is proven to be negative for rabies by lab techniques 26 27. Riskassessment Local treatment of wounds Administration of biologicals for passive immunization Vaccine administration27 28. Cleansing Chemicaltreatment Suturing Anti-rabiesserum Antibiotics and anti-tetanus measures28 29. Intramusculara)b.regimens 5 dose(Essen regimen) one dose on days 0,3,7,14,28(deltoid or thigh) Abbreviated multisite i.m. regimen(Zagreb)2-1-1 one dose into left and right deltoid on day 0 one dose deltoid on days 7 and 21. 29 30. Intradermala)b)regimens Updated Thai Red Cross2-2-2-0-2regimen 0.1 ml i.d. at 2 different lymphatic drainage sites(left and right deltoid) on days 0,3,7,28. Eight site i.d. regimen8-0-4-0-1-1 0.1 ml on arms,suprascapular,lower abdomen,thighs on day0 0.1ml on arms.thighs on day7 0.1 ml 0n days 28,90. 30 31. Onedose i.m or i.d on days 0 and 3. Local wound treatment No RIG31 32. Antisepsisand local infiltration of RIG in those with low CD4 counts Cat 2 exposures need RIG too.32 33. Educatingchildren to avoid contact with stray or wild animals Avoid trying to capture or provoke stray animals Avoid touching animal carcasses Secure garbage33 34. Privateroom (dark and noise free) Sedation iv morphine Muscle relaxants Life support measures(avoid intubation)34 35. Caninemass parenteral vaccination campaigns Oral vaccination of dogs Animal birth control35 36. http://emedicine.medscape.com/article/122714-treatment#a1128 (accessed on 6/03/13 at 5.05pm) Wallace. Public health and preventive medicine, 13th edition http://www.who.int/nutrition/publications/micro nutrients/IDD/WHO_NUT_96.13/en/index.htm l (accessed on 6/03/13 at 6.08pm) http://www.who.int/nutrition/publications/micro nutrients/IDD/WHO_NUT_94.4/en/index.html (accessed on 6/03/13 at 6.28pm) 36