Rabiesepidemiology, pathogenesis, public health concerns and. By far the predominant target of rabies virus infection in vivo is the neuron 1. Rabies virus, epidemiology, transmission and freeroaming cats. I in this study were immunized with modified live virus rabies vaccine of chick embryo ori gin lederle. Minimal inflammation and neuronal cytopathy may be observed even postmortem. Immediately after challenge 32 ld50 of the injected virus were demonstrable in the brain, but 6 hours later no virus could be found there. Rabies virus travels through the nerves to the spinal cord and brain. Rabies is a preventable viral disease commonly transferred through the bite of a rabid animal. They named human rabies hydrophobia, which means fear of water, a symptom shown by rabies victims.
Who guide for rabies pre and post exposure prophylaxis in humans. Murphy division o viral diseases, centers for disease control, atlanta, ga 30333 usa after devoting four years to the study of rabies, pasteur said. Clinical stages of rabies can progress from incubation period 5 days. Pdf rabies epidemiology, pathogenesis, public health concerns. The dogs are the major reason behind this, approximately 99% human deaths caused by dogs bites. The clinical course of rabies in dogs and that it could be transmitted by bite has been known for over 4000 years tierkel, 1975. In dogs showing signs, rabies was not invariably fatal. Information presented here on the diagnosis, pathogenesis, clinical signs, and prevention of rabies virus infection are generally applicable to other lyssaviruses as well.
Optimized pdf comparative pathogenesis of rabies and rabies like viruses. Pathophysiology has been best characterized in canine rabies variants. There are many unanswered questions in rabies pathogenesis, although there has been recent progress. Rabies virus infection is remarkable for the lack of evident pathology in the face of dramatic neurological symptoms.
P comparative pathogenesis of rabies and rabies like. Viral encephalitis is characterized by acute fever, headache, and evidence of parenchymal brain involvement such as changes in mental status and seizures. Explain the pathogenesis and epidemiology of rabies virus. Rabies is a viral zoonosis that causes approximately 50,000 to 100,000 deaths per year worldwide. Pathogenesis of rabies infection, pathogenesis of rhabdoviruses.
Rabies virus from the infected saliva enters the wound. Batacquired rabies is becoming increasingly common, and its diagnosis could be missed partly because its clinical presentation differs from that of dogacquired rabies. Asaresult ofinvestigations carried outduringthe past 10years onthepathogenesis ofpoliomyelitis, it became essential to reconsider also the problem of the pathogenesis of rabies. Human rabies can be effectively prevented, but it remains an almost invariably fatal disease despite aggressive approaches to therapy14.
A better understanding of rabies pathogenesis may be helpful in making future advances in. In addition, high titers of rabies virus can be produced in muco. Clinical stages of rabies can progress from incubation period 5 days to 2 years. Studies on the pathogenesis of rabies behaviour ofthe virus in the cns in the initial experiment, 50 mice were infected with 1600 ld50 by the intracerebral route. Pathogenesis of rabies table 1 sparing effect of removing portions of sciatic andor saphenous nerves on outcome of infection in animals inoculated in the footpad with rabies virusa neurectomy sciatic nerve only sapherious nerve only sciatic and saphenous nerves controls mice guineapigs rats hamsters foxes dogs cvs s lep cvsstrain, pool 5 cvs cvs. Rabies occurs in more than 150 countries and territories. Dogs are the principal transmitter of rabies to man and animals in most countries of africa, asia and south america, where they are responsible for over 95% of the human rabies cases reported worldwide who, 1989. Virus multiplies in muscle or connective tissue at the site of inoculation and then enter peripheral nerves via motor end plates at neuromuscular junction and spread upto the cns. Rabies disease, etiology and pathogenesis veterinary office of. Craig hooper,heather carbaugh,zhen fang fu,hilary koprowski, and bernhard dietzschold center for neurovirology, department of microbiology and immunology, thomas jefferson university, 1020 locust street, philadelphia, pa. Dogs are the major vector, especially in developing countries. Identify the most appropriate tests available to diagnose rabies. Pathogenesis of rabies virus infection in dogs clinical. Transmission and pathogenesis rabies bulletin europe.
To date, 16 different lyssaviruses have been described. When suspect rabid animal contacts excluding bats occur. Globally, rabies virus is the most important member of the genus. It affects humans as well as domestic and wild animals. Publication of this manuscript was made possible through an unrestricted educational grant provided by merck frosst canada ltd. The selective affinity of various tissues of the bat for rabies virus was shown by viral assay in 3 to 4weekold white swiss mice. Comparative pathogenesis of rabies in bats and carnivores. The rabies vaccine will be administered on days 0 and 7. Foundations of prevention and control dog rabies vaccination, en masse minimization of human exposures to infected animals prompt wound care and prophylaxis with vaccine and rabies immune globulin after exposure regulations to support the diseasefree status of many localities, due to the introduction of rabid animals e. In namibia, kudu tragelaphus strepsiceros were affected in 1977, and about 50,000 died from. Rhabdovirus, lyssavirus genus the family rhabdoviridae consists of more than 185 different viruses isolated from both plants and animals. Fu, in rabies third edition, 20 2 virus entry into the nervous system 2.
Rabies is a zoonotic disease that remains an important public health problem worldwide and causes more than 70,000 human deaths each year. In this article we will discuss about rabies in animals. Rabies pathogenesis alan c jackson departments of medicine and microbiology and immunology, queens university, kingston, ontario, canada. Who guide for rabies pre and post exposure prophylaxis in. The results indicate conclusively that rabies virus is ordinarily transmitted from the site of exposure to. The virus is usually transmitted to humans by infected saliva through the bite of a rabid animal. After inoculation, the rabies virus progresses from the subcutaneous tissue or muscle into peripheral nerves. Rabies epidemiology, pathogenesis, public health concerns and advances in diagnosis and control. The authors have investigated the spread of fixed and street strains of rabies virus from the site of injection to the central nervous system and salivary glands in various animal species. Dogs are the principal source of human rabies mortality, contributing up to 99% of all rabies transmissions to humans. Nevertheless, it has been shown that rabies virus can infect myocytes before the virus infection reaches neurons in the spinal cord or dorsal root ganglia 1, 2. The results indicate conclusively that rabies virus is ordinarily transmitted from the site ofexposure to the central nervous system via the peripheral nerves but that. The causative agent of rabies is rabies virus rv, a. The door to studies of rabies pathogenesis was first opened in 1804 by zinke 3, who experimentally transmitted rabies by swabbing the saliva of rabid dogs onto.
From the experimental observations it can be concluded that the rabies virus travels alongorin thenervesfromtheperipheryto thecentralnervoussystemandvice versa. Rabies virus is an enveloped, singlestranded rna virus with bullet shaped or rodshaped morphology. Apr 08, 2019 pathogenesis of rabies rabies is a viral disease which affects all mammals. The virus enters the body through transdermal inoculation i. In the past, anti rabies sera were associated with numerous side effects, serum sickness, and anaphylactic reactions in about 40% of cases 56. Rabies virus structure and pathogenesis learn microbiology. The cycle arose as a result of bites barbier, 1929, p. Progress of the vulpine rabies front in canada, 19461962 blancou et al. Rabies serum is a concentrated and purified solution of anti rabies antibodies prepared from equines immunized with anti rabies vaccine. The role of apoptosis in the pathogenesis of rabies the pathogenicity of rv correlates inversely with its capacity to induce neuronal apoptosis. A study guide provides an overview of rabies, its pathophysiology, assessment findings, medical management, and nursing care management. Rabies virus has high neuroinvasiveness and high neurovirulence readily spreads to the cns, leading to 100% mortality in the absence of early treatment. It is the member of the family rhabdoviridae and the genus lyssavirus.
Schematic of dynamics of rabies virus pathogenesis. When the virus is 1 introduced through a bite, it begins to replicate in the skin or muscle tissue. Rabies virus is excreted in saliva of rabid animal so, human acquire virus by the bite of rabid animals. The causative agent is rabies virus rv, a negativestranded rna virus of the rhabdovirus family. Feb 21, 2012 rabies is an avertable viral disease caused by the rabid animal to the warm blooded animals zoonotic especially human. Rabies is an infectious viral disease caused by rabies virus. Request pdf pathogenesis of rabies rabies is a central nervous system cns disease that is almost invariably fatal.
Rabies is a central nervous system cns disease that is almost invariably fatal. Our understanding of the pathogenesis of this disease comes mostly from studies using experimental animals, particularly rodents, and xed strains of rabies virus jackson, 2002. The mortality of rabies is almost 100 %, and it has been estimated by the who that more than 55,000 human deaths are caused by rabies through bites from rabid animals annually worldwide with the. Initiation of pep should not await the results of laboratory diagnosis or be delayed by dog observation when rabies is suspected 7. Rabies molecular virology, diagnosis, prevention and. It is usually contracted through a bite from an infected animal, though transmission can occur if the virus is introduced onto any mucous membrane eyes, nose, mouth. If rabies immunoglobulin is not available on first visit, use can be delayed by up to 7 days from the date of the first vaccine dose 6. Viral infection and transit from inoculation site to the central nervous system. A better understanding of rabies pathogenesis may be helpful in making future advances in the therapy of human rabies. In most cases the disease is transmitted via the bite of rabid animals which shed infectious virus with their saliva. Oct 01, 1985 paris 1985 1985, 6 e, 373386 the pathogenesis and pathology of rabies virus infection by f. Rv pathogenesis, like that of other viruses, is a multigenic trait.
Rabies is estimated to cause at least 55 000 deaths per year worldwide, about 56% of which occur in asia and 44% in. Pathophysiology the organism causing rabies is called r abies virus rv, a negativestranded rna virus of the rhabdovirus family. The pathogenesis and pathology of rabies virus infection. Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus lyssavirus and family rhabdoviridae. Pdf on sep 1, 2002, alan c jackson published rabies pathogenesis find, read and cite all the research you need on researchgate. Aug 11, 2012 all about rabies epidemiology of rabies, pathogenesis of rabies, clinical features of rabies, treatment of rabies, prevention of rabies, rabies virus, post exp slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Pdf pathophysiology of human paralytic rabies supaporn. Department of pediatrics, infectious diseases, medical college of georgia, augusta, ga after completing this article, the reader should be able to. Rabies is an acute encephalomyelitis that causes disease in the human host via two features associated with the rabies virus rv. The greeks called rabies lyssa or lytta, which means frenzy or madness.
By continuing to use our website, you are agreeing to our use of cookies. Figure 1 depicts an idealized outline of dynamics of rabies virus pathogenesis in the presence and absence of pepmediated immune responses. There is still much to be learned about the pathogenesis of rabies in mammals, particularly with respect to species variations during the incubation period, the natural cycles in wildlife, and salivary shedding infectious periods. Rabies is as old as antiquity, but the disease remains an important public health problem today. The development of rabies could be prevented with amputation and the timing of the procedure was found to be critical. Rabies or hydrophobia fear of water is a highly fatal infection of encephalomyelitis, which affects all warmblooded animals including humans, domestic and wild animals moran, 2002. The results indicate conclusively that rabies virus is ordinarily transmitted from the site of. Early studies in rabies pathogenesis, which were performed in order to establish the pathways and rate of viral spread, involved amputation of the tail or leg of an animal proximal to the site of inoculation with a fixed or street wildtype strain of rabies virus. Rabies is a classic zoonosis, which means that it is an illness that is passed directly from animal to animal and from animal to human. Recent findings indicate that in addition to the rv g protein viral elements that regulate gene expression, especially expression of the l gene, are also likely to play a role in rv pathogenesis. This lecture will discuss the pathogenesis, clinical manifestations, and numerous causative agents of viral encephalitis, the manifestation of viral infection of the brain parenchyma. Up to 20% of dogs recovered without any supportive treatment.
Rabies virus, epidemiology, transmission and freeroaming. Most dogs experimentally infected with street rabies virus showed clinical signs of rabies before death, but up to 18% of the dogs died without showing detectable signs of illness. Pathogenesis of rabies rabies is a viral disease which affects all mammals. Bourne from the southwest rabies investigations station, national communicable disease center, public health service, us department of health, education, and welfare, university park, new mexico, usa. Many aspects of rabies pathogenesis in human neurons are not well. Pathogenesis of rabies virus is an animal infected by rabid animal. The commonest mode of transmission in man is by the bite of a rabid animal or the contamination of scratch wounds by virus infected saliva. Rabies, present on all continents and endemic in most african and asian countries, is a fatal zoonotic viral disease, transmitted to humans through contact mainly bites and scratches with infected animals, both domestic and wild. Recent findings indicate that in addition to the rv.
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