Rhabdoviruses Rhabies virus is the medically important member

Rhabdoviruses Ø Ø Ø Ø Rhabies virus is the medically important member of the rhabdovirus. It has a single-stranded RNA. It has bullet-shaped capsid surrounded by a lipoprotein envelope. The virion contains an RNA polymerase. Rabies virus has a single antigenic type. It can infect all mammals. Virus isolated directly from infected animals is called (street virus). Virus passaged in rabbit brains is (fixed virus).

Factor determine the incubation period 1. 2. 3. 4. Virus concentration in the inoculum. Proximity of the wound to the brain. Severity of the wound. Host immune status.

Postexposure vaccination decision u 1. 2. 3. 4. The decision depend on : The type of animal (all wild animal demand immunization). The severity of the bite and its location. If the attack by domestic animal , whether the animal immunized or available to be observed. Whether Rabies is endemic in the area.

Types of human rabies vaccine Ø 1. 2. 3. 4. Ø 1. 2. 3. Ø 1. 2. 3. Simple vaccine Phenole –inactivated virus vaccine prepared in brains of rabbits , sheep or goats. , Widely used in developing countries. Cheape , liable to cause neuroparalytic reaction. Given as 21 injections subcutaneusly. Duck embryo vaccine Virus in activated with Beta-propiolactone. Free from neural tissue. Cause allergic reactions , relatively ineffective antigen. Human diploid cell strain virus (HDCS) Virus inactivated with Beta prpiolactone. The most widely used vaccine in developed countries. Expensive Full course of HDCS vaccine consists of 6 doses given on days 0, 3, 7, 14 , , 30 and 90 days.

Treatment and Prevention of Rabies Preexposure and post exposure control. Ø Ø Ø Preexposure Immunization of individuals in high-risk such as, zoo keeper , veterinarians , travelers to hyperendemic areas. Postexposure Rabies is a viral infection that, if untreated , is always fatal. Postexposure immunization involve the use of Vaccine and human rabies immune globuline (HRIG).