Animal Rabies diagnosis & Research laboratory

• Introduction
• Routine service
• Aetiology
• Epidemiology & Infection
• Clinical disease
• Laboratory diagnosis

Aetiology

     Rabies is a viral disease of all warm-blooded mammals with an almost worldwide distribution. The virus is present in the saliva and nervous system tissue of infected animals. Disease transmission is invariably via the bite or through of the infected fluid with cuts or wounds in skin or mucous membranes that is excreting the virus in its saliva. Rarely; the infection can be transmitted through the respiratory system when the virus is inhaled. The mortality rate is close to 100 % .Once clinical signs appear in the bite victim, death from rabies is nearly always the outcome. Worldwide, probably more than 50 000 human deaths from the disease occur annually as a result of bites from rabies-infected dogs. In nature, no fish, reptiles, or birds have been found to be rabid.

Classification
      Rabies viruses are of the Order Mononegavirales , Family Rhabdoviridae , genus Lyssavirus . The Rhabdoviridae are characterized by a negative-sense genome of single-stranded RNA and the family is divided into two genera, Vesiculovirus , which includes the viruses causing vesicular stomatitis and antigenically related viruses, and Lyssavirus , which includes rabies and the rabies-related viruses

Temperature

Chemical

     Relatively stable at pH 5–8. Grows better in cultures slightly on the alkaline side of neutrality. Sensitive to lipid solvents (soap solution, ether, chloroform and acetone, although acetone does not completely inactivate the virus), 40–70% ethanol, iodine preparations and quaternary ammonium compounds. Disinfectants which contain iodine are particularly useful for decontamination of laboratory instruments and surfaces, but because of the contained acid, contact with skin should be avoided.

Environmental conditions

      The virus is sensitive to ultraviolet light, but has frequently been isolated from the brains of animals in the field, even when they are decomposed. The virus is resistant to drying and can withstand repeated freezing and thawing.