PICORNAVIRIDAE

PETER H. RUSSELL, BVSc, PhD, FRCPath, MRCVS

Department of Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 OTU.

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Objective

Students should be able to:

• be aware of swine vesicular disease as a notifiable disease.

• evaluate rhinoviruses as pathogens of the upper respiratory tract.

• describe in detail the importance of serotypes, subtypes and virus protein 1(VP1) of foot and mouth disease virus (FMDV) [notifiable disease].

• compare and contrast the methods of control of FMDV in the EU and endemic areas

General properties

ENTEROVIRUSES

SWINE VESICULAR DISEASE (SVD)

ENTEROVIRUSES

(cont.)

GENUS APTHOVIRUS FOOT AND MOUTH DISEASE VIRUS

VIRUS:

The RNA is translated into a single polyprotein which is cleaved into the 4 virus proteins by a viral protease.

VIRUS: Physio-Chemical Properties:

VIRUS: Serotypes on VP1:

VIRUS: Subtypes:

PATHOGENESIS AND CLINICAL SIGNS:

Primary replication is at the epithelium of the upper respiratory tract or alimentary tract. Aerosol virus is excreted during this incubation period. After viraemia the virus targets the stratum spinosum of stratified squamous epithelia and mucous membranes where external secondary vesicles appear after an incubation period of 2-14 days.

TRANSMISSION:

IMMUNITY:

DIAGNOSIS:

CONTROL

UK !!!!! YOU MUST REPORT CLINICAL LESIONS:- MILK DOWN, LAMENESS, BLANCHED EPITHELIUM PROGRESSING TO VESICLES, CRUSTS, SALIVATION.

!!!!

CONTROL

Slaughter and disinfection.

ENDEMIC AREAS

The vaccines

Summary

• FMDV is exotic to the UK and a notifiable disease with attempts to contain the disease within infected areas .

• Rapid slaughter of infected animals, after confirmation by ELISA for serotype in vesicle fluid. • Vaccinate with 2-3 circulating subtypes in an endemic area.