Quantities of infectious virus and viral RNA recovered from sheep and cattle experimentally infected with foot-and-mouth disease virus O UK 2001

• Published in: Journal of general virology 2002-08, Vol.83 (8), p.1915-1923
• Main Authors: Alexandersen, S, Zhang, Z, Reid, S. M, Hutchings, G. H, Donaldson, A. I
• Format: Article
• Language: English
• Subjects: Aerosols; Air Microbiology; Animals; Antibodies, Viral - blood; Cattle; Cattle Diseases - transmission; Cattle Diseases - virology; Foot-and-Mouth Disease - transmission; Foot-and-Mouth Disease - virology; Foot-and-Mouth Disease Virus - genetics; Foot-and-Mouth Disease Virus - isolation & purification; Foot-and-Mouth Disease Virus - pathogenicity; Nose - virology; Rectum - virology; RNA, Viral - analysis; RNA, Viral - blood; Sheep; Sheep Diseases - transmission; Sheep Diseases - virology; Specimen Handling - veterinary; Virus Shedding
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-83-8-1915

Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK 1 Author for correspondence: Soren Alexandersen. Fax [phone]. e-mail soren.alexandersen{at}BBSRC.ac.uk 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.