1. RABIES Properties: @ Rabies belongs to Rhabdovirus family @ It is the only human Rhabdovirus virus @ It is bullet-shaped, enveloped, helical, single stranded, linear RNA.

3. Symptoms: @ Incubation period is 10 days to 1 year. @ Fever, malaise, nausea, headache. @ Difficulty in sleeping, night mares. @ Hyperexcitability, muscle spasms @ Hydrophobia, aerophobia, anxiety @ Aggression, coma, death.

5. Classification of Rabies: @ Furious rabies, characterized by: * Hyperexcitability * Muscle spasms * Hydrophobia @ Dumb rabies, presents with: * paralysis only.

7. Pathogenesis of Rabies: @ Virus in saliva, enters at the site of a bite, or licking cut skin @ Virus replicates at the site of the bite. @ Virus enters peripheral nerves, then the spinal cord, and then the brain. @ Many viral replication occurs in brain @ Virus goes back to salivary glands, heart, lung, liver, skin, retina, cornea.

9. Laboratory Diagnosis of Rabies In Man @ Specimens: Saliva, CSF, Urine @ Immunofluorescence of cornea smears and skin biopsy of neck or face @ Isolation by inoculating saliva in mice. @ Detection of antibodies by serology @ RNA detection by PCR in blood

11. Lab. Diagnosis of Rabies In Animals @ Cytology of brain tissue for Negri inclusion bodies in nerve cells. @ Immunofluorescence to detect rabies antigens in the brain @ Isolation by inoculating mice. @ Electron microscopy to detect the bullet-shaped virus.

13. Rabies in Animals: @ Rabies is endemic all over the world except Australia and Antarctica. @ Virus infects all warm-blooded animals, bats, and birds. @ Urban rabies is transmitted by dogs. @ Head and neck bites are more serious

15. Vaccination: @ Vaccine consists of an inactivated virus grown in human embryo lung cells @ It is given as a course of 6 I.M. injection on days 0, 3, 7, 14, 28 and 90 @ Patients with deep or multiple bites should also be injected by rabies immunoglobulins @ Dogs are vaccinated by another inactivated vaccine

17. Creutzfeldt-Jakob Disease (CJD) Symptoms: @ Progressive dementia, ataxia @ Jerky movements, Difficulty in speech Aetiology: @ CJD is known as mad-cow disease @ Caused by prions virus PrP 27-30 Creutzfeldt Photo

19. Prions @ They are viruses composed of protein only, without nucleic acid. @ Resistant to UV light, heat, nucleases, and formaldehyde @ Inactivated by hypochlorite, Na OH, and autoclaving. @ Composed of a single glycoprotein.

21. Transmission of CJD: @ CJD involves the CNS only @ With long IP (20 years). It is fatal @Transmission via: corneal grafts, growth hormone (given to dwarf children), FSH (given to infertile women). @ Surgeons & lab. staff are at risk. @ Transmission from Mad Cow not certain

23. Lab. Diagnosis @ Spongiform pathology of the brain detected by MRI. @ Detection of PrP 27-30 prion virus at postmortem and in blood by PCR @ May be 10-15% hereditary.