Rhabdoviruses 桿狀病毒

I. Classification Genus –Lyssavirus ： rabies virus ( 狂犬病毒屬 ) Three rabies-like viruses

II. Structure Bullet-shaped, single-stranded, negative-sense enveloped RNA virus Single segment The virus genome encodes five proteins.

III. Multiplication Replication in cytoplasm Parental (-) RNA virus --- ＞＋ RNA --- ＞ progeny-RNA virus.

IV. Clinical manifestation Cause acute infection of the central nervous system. –Five stages in humans ： incubation -- ＞ prodrome( 前驅期 ) -- ＞ acute neurologic period 急性腦炎（神經錯亂） → 腦幹中樞功 能障礙期（多口水，恐水症） -- ＞ coma( 昏 迷 ) -- ＞ death( 死於神經及呼吸衰竭 ) Incubation time ： 5 days to 2 years

V. Pathogenesis replicate in muscle tissue-- ＞ remaining sequestered at or near the entry site during incubation-- ＞ entering the peripheral nervous system- - ＞ migrating rapidly to numerous organs.

VI. Hosts defenses Antibody is protective only if present before virus enters the nerves.

VII. Epidemiology occur in nearly all countries due to a bite by an infected mammal.

VIII. Diagnosis Symptom observation and the detection of antibody are too late for clinical purpose. Tests of viral antigen or serological finding are used for suspected animal. Negri body in infected neurons, eosinophilic cytoplasmic inclusion filled with viral nucleocapsids is a hallmark diagnosis for rabies.

IX. Control Control is by vaccination of susceptible animal species, particularly dogs and cats. Vaccination with HDCV for pre-exposure prophylaxis. Administration of both HRIG ( 抗狂犬病毒免疫 血清 ) and vaccines around the wound for post- exposure prophylaxis.