Quantities of infectious virus and viral RNA recovered from sheep and cattle experimentally infected with foot-and-mouth disease virus O UK 2001.
The profiles of virus production and excretion have been established for sheep experimentally infected with the UK 2001 strain of foot-and-mouth disease (FMD) virus by inoculation and by direct and intensive contact. Virus replicated rapidly in the inoculated sheep, from which a peak infectivity of airborne virus of 10(4.3) TCID(50) per sheep per 24 h was recovered. Around 24 h later, contact-infected sheep excreted airborne virus maximally. Similar amounts of airborne virus were recovered from cattle. The excretion of virus by the sheep under these conditions fell into three phases. First, a highly infectious period of around 7-8 days. Second, a period of 1-3 days soon afterwards when trace amounts of viral RNA were recovered in nasal and rectal swabs. Third, at 4 weeks after exposure, the demonstration, by tests on oesophageal-pharyngeal samples, that 50% of the sheep were carriers. The implications of the results and the variable role that sheep may play in the epidemiology of FMD are discussed.
Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1.
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Alexandersen
Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1.
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Z
Zhang
Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1.
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Reid
Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1.
G H
GH
Hutchings
Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK1.
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AI
Donaldson
D000336:Aerosols; D000391:Air Microbiology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission / Q000821:virology*; D005536:Foot-and-Mouth Disease / Q000635:transmission / Q000821:virology*; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D009666:Nose / Q000821:virology; D012367:RNA, Viral / Q000032:analysis / Q000097:blood; D012007:Rectum / Q000821:virology; D012756:Sheep; D012757:Sheep Diseases / Q000635:transmission / Q000821:virology*; D013048:Specimen Handling / Q000662:veterinary; D017201:Virus Shedding
D000336:Aerosols; D000914:Antibodies, Viral; D012367:RNA, Viral