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 --＞ pr

odrome( 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 prop

hylaxis.

• Administration of both HRIG (抗狂犬病毒免疫血清 ) and vaccines around the wound for po

st-exposure prophylaxis.