Biology 218 - Lecture 21: Rhabdoviridae (1999) I. Rhabdoviridae - rabies, vesicular stomatitis virus Historical - Pasteur vaccination of rabid rabbit spinal cord into rabies victim Joseph Meister. (public spectacle) A. Virology - bullet-shaped. ssRNA, negative stranded, 11 kbp, G protein (spike) elicits neutralizing antibody. Replication: (Most work done with VSV) Bind by spike protein (G), endocytosed -> nucleocapsid into cytoplasm. Replicate, minus strand encapsidated, buds at G-protein peplomer region. B. Clinical - (all warm-blooded animals susceptible) Ex. Vampire bats -> 1 million cattle deaths/year in South America. 1. Epidemiology - Island countries: None in Australia, Japan, New Zealand, Hawaii. Developing countries: Asia, Africa....domestic animals Industrialized countries: US, Europe..... Enzootic in animals (bat, racoon, fox...) 2. Transmission - saliva through cut -> replication in muscle-> nerve cells (bind Ach receptor) neuromuscular junction -> CNS -> coma -> respiratory arrest Rare transmission: corneal transplant from rabies patient Wide host range: Infection of CNS -> aggressive simultaneous with high titer in saliva. Butte: Skunks, bats (We're #1 .....or 2) Young rural dogs and cats responsible for estimated 75,000 human cases/year. 3. Disease - Long incubation (little immune response) - 14 - 90 days. Prodrome - flu-like rogressive: hydrophobia, aerophagia, hallucinations, aggression, convulsions, progressive paralysis C. Diagnosis - FA of brain or Nebri bodies (cytoplasmic inclusions) in brain, viral isolation. D. Treatment - passive and active immunization during muscle replication before nerve invasion. Only human disease treated by post-exposure vaccination. Vaccine now grown in human cells - highly immunogenic (4 - 6 injections instead of 14 - 21) E. Control: Vaccination of dogs and cats (each 3 years) Humans at risk: Vets, animal control, wildlife workers every 2 years (confirm adequate Ab serology) Vaccinia-rabies (recombinant) vaccinationof wild foxes.