Rabies prevention

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comprehensive presentation on Rabies Prevention Concepts on pathogenesis, Active and Passive Immunisation

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  • 1. Understanding Rabies Disease and Prevention Dr (Lt Col) Ashutosh Ojha 151 Army Base Hospital,India ashutosh8116@gmail.com1

2. Section 1 Rabies disease background 3. 3Benenson 1995 Mal ariaoxru s al lpta vigu eerle raNo treatmentSmHa nD enetisfe vCh ogiag uen inPlaxie san th rRa blo w.micYe lMonat io numha lPn eInCase fatality rateRabies is virtually 100% fatal Treatment100 90 80 70 60 50 40 30 20 10 0 4. Rabies Rabies is an ancient disease Painting of a rabid dog biting a man Arabic A.D. 1224 Baghdad school, by Abdallah ibn al-Fadl4Picture courtesy of Smithonian Institution, Washington D.C. 5. The rabies virus Taxonomy: Family: Rhabdoviridae Genus: Lyssavirus Species: Rabies virus bullet-shaped, ~180 nm long and ~75 nm wide single-strand, negative sense RNA 5CDC 2007; Bleck 2005 6. Pathogenesis: Exposure Bite transmission Human infection by rabies virus usually occurs as a result of a transdermal bite from an infected wild or domestic animalNon-bite transmission Scratches from a rabid animal Saliva from a rabid animal comes into contact with a victims mucous membranes or fresh skin lesionsRare cases have been reported via: Inhalation of virus-containing aerosols Human-to-human transmission through transplantation 61. Bleck 2005; 2. WHO 2004 7. How does the Rabies virus travel from wound to brain 8. Human rabies: Clinical stages ExposureFirst clinical signsFirst neurologic signsOnset of comaDeathIncubation periodProdrome phaseAcute neurologic phaseComaUsual duration 20-90 days2-10 days2-7 days0-14 daysClinical stageOnset of rabies symptoms may start rather late, ie, onset of symptoms documented months, even years, after exposureDeath usually occurs within a few days after the appearance of clinical symptoms 81. Jackson 2007; 2. Hemachudha 2002 9. Clinical rabies in humans Two forms of rabies are distinguished: Furious (75-80%) (encephalitic; three-forth of all cases): Rabies transmitted from dogs is usually furious Paralytic (20-25%) (dumb; one-fourth of all cases) Clinical Presentation: First clinical symptoms: non-specific, i.e., malaise, fever, and headache Paresthesia: pain and abnormal feelings at the wound site are common Acute neurologic phase: including throat spasms with an inability to swallow, and anxiety, confusion, and hallucinations: Hydrophobia (only documented in humans), respiratory spasms with aerophobia, hyperactivity only exhibited with furious rabies Ascending paralysis or a symmetric quadriparesis only exhibited with paralytic rabies Coma and death 9Jackson 2002 10. Rabies in children Due to their short stature, children are susceptible to bites on face, scalp, and upper part of the body Children are more susceptible to animal bites by playing in open grounds or in streets Children cannot ward off animals easily Children are more likely to provoke animals Children might not report a bite or scratch40-60% of all animal bite cases are reported to occur in children 610032121IM (Essen) 6 dose4 (HRIG)45656IM (Essen) 6 dose41 (ERIG)19-3410051252145IM 2-6 doseno RIG>1210015100100% survival rate of subjects after exposure to laboratory-confirmed rabid animals Current Essen regimen administration is Days 0, 3, 7, 14, and 2834References on note page 34. Immunogenicity following the Thai Red Cross ID regimen36Briggs 2000100GMC (IU/mL)Adults who had received WHO Category II and III wounds administered ID rabies vaccine on Days 0, 3, and 7 (two sites) and Days 30 and 90 (one site) PCECV 0.1 mL PVRV 0.1 mL Rabipur is welltolerated and immunogenic when following the Thai Red Cross ID regimenPCECVPVRV101 0.107143090Time following immunization (days)0.5 IU/mL 35. Efficacy studies (ID) No. of subjects Category No. of Vaccination No. of Followexposed to of Study subjects schedule subjects who up period proven contact (total) received RIG (months) rabid animalsSurvival rate (%)1148148I, II, or IIIID 2-site (TRC)3 billion people are at risk of infection in >100 countries The WHO estimates that the annual number of human rabies deaths worldwide is ~55,000, and most occur in Asia and Africa40 39. Summary - II There are two active immunization strategies available to prevent rabies in humans: Pre-exposure vaccination protects against potential exposure to rabies particularly vulnerable children, individuals who live in or travel to high-risk areas or work in high-risk occupations Post-exposure prophylaxis (PEP) is administered following contact with a suspected or confirmed rabid animal. The WHO and CDC provide guidelines for both strategies PCECV is a purified chick embryo cell-culture rabies vaccine which provides active immunization and protection Approved by the US FDA (intramuscular regimen only) Recommended for each and every established WHO vaccination schedule where intradermal vaccination licensed Intradermal administration is currently licensed in India, Myanmar, the Philippines, Sri Lanka, Thailand, and Vietnam; regulatory approval will continue to be adapted for other countries 41 40. Summary - III PCECV has been available for post-exposure and preexposure prophylaxis since 1984 The immunogenicity, efficacy, and safety profiles of PCECV are well established and have been evaluated in >90 clinical trials worldwide42