Aerosol transmission of foot-and-mouth disease virus Asia-1 under experimental conditions.
Foot-and-mouth disease virus (FMDV) control measures rely on understanding of virus transmission mechanisms. Direct contact between naïve and infected animals or spread by contaminated fomites is prevented by quarantines and rigorous decontamination procedures during outbreaks. Transmission of FMDV by aerosol may not be prevented by these control measures and this route of transmission may allow infection of animals at distance from the infection source. Understanding the potential for aerosol spread of specific FMDV strains is important for informing control strategies in an outbreak. Here, the potential for transmission of an FMDV Asia 1 strain between pigs and cattle by indirect aerosol exposure was evaluated in an experimental setting. Four naïve calves were exposed to aerosols emitted from three infected pigs in an adjacent room for a 10h period. Direct contact between pigs and cattle and fomite transfer between rooms was prevented. Viral titres in aerosols emitted by the infected pigs were measured to estimate the dose that calves were exposed to. One of the calves developed clinical signs of FMD, whilst there was serological evidence for spread to cattle by aerosol transmission in the remaining three calves. This highlights the possibility that this FMDV Asia 1 strain could be spread by aerosol transmission given appropriate environmental conditions should an outbreak occur in pigs. Our estimates suggest the exposure dose required for aerosol transmission was higher than has been previously quantified for other serotypes, implying that aerosols are less likely to play a significant role in transmission and spread of this FMDV strain.
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK. Electronic address: claire.colenutt@pirbright.ac.uk.
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Colenutt
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK; Central Veterinary Institute (CVI), Wageningen UR, P.O. Box 65, 8200 AB Lelystad, The Netherlands, The Netherlands.
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JL
Gonzales
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK.
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DJ
Paton
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK; Met Office, FitzRoy Rd, Exeter, EX1 3PB, UK.
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Gloster
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK; Met Office, FitzRoy Rd, Exeter, EX1 3PB, UK.
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Nelson
The Pirbright Institute, Ash Road, Pirbright, Woking, GU24 0NF, UK.
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Sanders
D000336:Aerosols; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission*; D005536:Foot-and-Mouth Disease / Q000635:transmission*; D029544:Foot-and-Mouth Disease Virus / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000635:transmission*; D019562:Viral Load; D014766:Viremia / Q000635:transmission / Q000662:veterinary*
D000336:Aerosols
Aerosol; Exposure dose; Foot-and-mouth disease virus; Transmission