Foot-and-mouth disease surveillance using pooled milk on a large-scale dairy farm in an endemic setting

Armson, B., Gubbins, S., Mioulet, V., Qasim, I. A., King, D. P. and Lyons, N. A. (2020) Foot-and-mouth disease surveillance using pooled milk on a large-scale dairy farm in an endemic setting. Frontiers in Veterinary Science, 7, 264. (doi: 10.3389/fvets.2020.00264) (PMID:32537458) (PMCID:PMC7267466)

Abstract

Pooled milk is used for the surveillance of several diseases of livestock. Previous studies demonstrated the detection of foot-and-mouth disease virus (FMDV) in the milk of infected animals at high dilutions, and consequently, the collection of pooled milk samples could be used to enhance FMD surveillance. This study evaluated pooled milk for FMDV surveillance on a large-scale dairy farm that experienced two FMD outbreaks caused by the A/ASIA/G-VII and O/ME-SA/Ind-2001d lineages, despite regular vaccination and strict biosecurity practices. FMDV RNA was detected in 42 (5.7%) of the 732 pooled milk samples, and typing information was concordant with diagnostic reports of clinical disease. The FMDV positive milk samples were temporally clustered around reports of new clinical cases, but with a wider distribution. For further investigation, a model was established to predict real-time RT-PCR (rRT-PCR) C values using individual cattle movement data, clinical disease records and virus excretion data from previous experimental studies. The model explained some of the instances where there were positive results by rRT-PCR, but no new clinical cases and suggested that subclinical infection occurred during the study period. Further studies are required to investigate the effect of vaccination on FMDV excretion in milk, and to evaluate more representative sampling methods. However, the results from this pilot study indicate that testing pooled milk by rRT-PCR may be valuable for FMD surveillance and has provided evidence of subclinical virus infection in vaccinated herds that could be important in the epidemiology of FMD in endemic countries where vaccination is used. [Abstract copyright: Copyright © 2020 Armson, Gubbins, Mioulet, Qasim, King and Lyons.]

• Item Type: Articles
• Additional Information: Funding: This study was carried out as part of a Biotechnology and Biological Sciences Research Council (BBSRC) CASE Ph.D. studentship (1646343), for which the authors acknowledge. The field work and sample testing were funded by the US Department of Homeland Security through Lawrence Livermore National Laboratory, supplemented by a fund for applied research from the European Commission for the Control of Foot-and-Mouth Disease (EuFMD). NL was supported by a BBSRC funded fellowship (grant code: BBS/E/I/00007004) and work at the Pirbright Institute was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) (BBS/E/I/00007035, BBS/E/I/00007036 and BBS/E/I/00007037).
• Keywords: foot-and-mouth disease, pooled milk, real-time RT-PCR, subclinical infection, surveillance, vaccination
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Armson, Bryony
• Authors: Armson, B., Gubbins, S., Mioulet, V., Qasim, I. A., King, D. P., and Lyons, N. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Frontiers in Veterinary Science
• Publisher: Frontiers Media
• ISSN: 2297-1769
• ISSN (Online): 2297-1769
• Published Online: 27 May 2020
• Copyright Holders: Copyright © 2020 Armson, Gubbins, Mioulet, Qasim, King and Lyons
• First Published: First published in Frontiers in Veterinary Science 7:264
• Publisher Policy: Reproduced under a Creative Commons License