diagnosis of rabies in humans seminar

RabiesDiagnosis-in Humans : 

RabiesDiagnosis-in Humans CH.HARIKRISHNA

Rabies- A Zoonotic Disease : 

2 Rabies- A Zoonotic Disease Rhabdovirus family; genus Lyssavirus Enveloped, bullet-shaped virions Slow, progressive zoonotic disease Primary reservoirs are wild mammals; it can be spread by both wild and domestic mammals by bites, scratches, and inhalation of droplets.

Rhabdoviruses : 

Rhabdoviruses A Bullet shaped virus/ Enveloped Contains ss RNA virus Rhabdoviridae – infects mammals. Important virus Lyssa virus- Rabies virus Lyssa means Rage.

Clinical presentation – Leads the clues in Diagnosis : 

Clinical presentation – Leads the clues in Diagnosis In most cases, human rabies is diagnosed primarily on the basis of clinical symptoms and signs, and a corroborative history of or evidence of an animal bite, death of an animal, and incomplete or no vaccination following exposure. The facility for laboratory diagnosis and confirmation of rabies, be it in humans or in animals, is available premortem in only a few institutions in India.

Slide 5: 

DIAGNOSIS Laboratory finding: ( CBC, CSF ) Exclusion of other etiologies Pathology: Formation of cytoplasmic inclusions: ( Negri bodies ) ( Ammon’s horn, Cerebral cortex, Brainstem, Hypothalamus, The Purkinje cells of cerebellum, Dorsal spinal ganglia )

Laboratory Diagnosis : 

Laboratory Diagnosis ISOLATION OF THE VIRUS Specimens like CSF,saliva,urine inoculated into mice brain.after death, mice brain is demonstrated for Negri bodies Isolation of virus from Mice brain inoculation. tissue culture on culture lines W 138, BHK-21, diagnosis is made by detection of rabies virus in inoculated tissue culture cells by immunofluorescence positive test can be obtained with in 2-4 days.

Immuno fluorescence test : 

Immuno fluorescence test Antigen detection by specific Immuno fluorescence. Ante-mortem - Conjunctival,skin biopsy from nape of neck. Postmortem - impression from surfaces of salivary glands Hippocampus, Histological examination specific antibody detection by ELISA in CSF. Detection of rabies virus RNA by reverse transcriptase PCR it is a sensitive method

Negri bodies – A gold standard in Diagnosis : 

Negri bodies – A gold standard in Diagnosis Inclusion bodies called Negri bodies are 100% diagnostic for rabies infection, but may not be found in about 20% of cases.

Negri bodiesin Brain Tissue : 

Negri bodiesin Brain Tissue Negri bodies  round or oval inclusion pinkish bodies seen in the cytoplasm and sometimes in the processes of neurons of rabid animals after death. Negri bodies have inner Basophilic granules,pathognomonic inclusion bodies (3-27 µm in diameter) . These are demonstrted by SELLERS technique

Common confirmatory test - Rabies : 

Common confirmatory test - Rabies The standard premortem test is a fluorescent antibody test to demonstrate the presence of viral antigen. The standard postmortem test is biopsy of the patient's brain and examination for Negri bodies. Autopsies are rarely performed.

Man’s best friendbut can spread Rabies if not vaccinated : 

Man’s best friendbut can spread Rabies if not vaccinated