بسم الله الرحمن الرحيم

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

Factor determine the incubation period 1. V irus concentration in the inoculum. 2. P roximity of the wound to the brain. 3. S everity of the wound. 4. H ost immune status.

Clinical syndromes of Rabies virus RRRRabies is almost always a fatal disease unless treated by vaccination TTTThe incubation period varies according to the site of the bite from 2-16weeks SSSSymptoms such as fever,malaise,headache, paine or itching at the site of bite. GGGGastrointestinal symptoms,fatigue anorexia typically occure. AAAAfter a prodrome of 2-10 days neurological symptoms appear (Hydrophobia) occurs in 20-50% of patients, confusion,increased salivation develop. WWWWithin few days,the disease may progressess to paralysis,and coma.

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

Types of human rabies vaccine SSSSimple vaccine 1. P henole –inactivated virus vaccine prepared in brains of rabbits,sheep or goats., 2. W idely used in developing countries. 3. C heape,liable to cause neuroparalytic reaction. 4. G iven as 21 injections subcutaneusly. DDDDuck embryo vaccine 1. V irus in activated with Beta-propiolactone. 2. F ree from neural tissue. 3. C ause allergic reactions, relatively ineffective antigen. HHHHuman diploid cell strain virus (HDCS) 1. V irus inactivated with Beta prpiolactone. 2. T he most widely used vaccine in developed countries.Expensive 3. F 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. PPPPreexposure IIIImmunization of individuals in high-risk such as, zoo keeper,veterinarians,travelers to hyperendemic areas. PPPPostexposure RRRRabies is a viral infection that, if untreated, is always fatal. PPPPostexposure immunization involve the use of Vaccine and human rabies immune globuline (HRIG).