title: Quantitative characteristics of the foot-and-mouth disease carrier state under natural conditions in India.
abstract: The goal of this study was to characterize the properties and duration of the foot-and-mouth disease (FMD) carrier state and associated serological responses subsequent to vaccination and naturally occurring infection at two farms in northern India. Despite previous vaccination of cattle in these herds, clinical signs of FMD occurred in October 2013 within a subset of animals at the farms containing juvenile-yearling heifers and steers (Farm A) and adult dairy cattle (Farm B). Subsequent to the outbreak, FMD virus (FMDV) asymptomatic carriers were identified in both herds by seroreactivity to FMDV non-structural proteins and detection of FMDV genomic RNA in oropharyngeal fluid. Carriers' seroreactivity and FMDV genome detection status were subsequently monitored monthly for 23 months. The mean extinction time of the carrier state was 13.1 ± 0.2 months, with extinction having occurred significantly faster amongst adult dairy cattle at Farm B compared to younger animals at Farm A. The rate of decrease in the proportion of carrier animals was calculated to be 0.07 per month. Seroprevalence against FMDV non-structural proteins decreased over the course of the study period, but was found to increase transiently following repeated vaccinations. These data provide novel insights into viral and host factors associated with the FMDV carrier state under natural conditions. The findings reported herein may be relevant to field veterinarians and governmental regulatory entities engaged in FMD response and control measures.
authors.affiliation: UMN, STEMMA Laboratory, Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Hayer
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: R
authors.initials: R
authors.lastname: Ranjan
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: J K
authors.initials: JK
authors.lastname: Biswal
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: S
authors.initials: S
authors.lastname: Subramaniam
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: J K
authors.initials: JK
authors.lastname: Mohapatra
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: G K
authors.initials: GK
authors.lastname: Sharma
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: M
authors.initials: M
authors.lastname: Rout
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: B B
authors.initials: BB
authors.lastname: Dash
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: B
authors.initials: B
authors.lastname: Das
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: B R
authors.initials: BR
authors.lastname: Prusty
authors.affiliation: ICAR-Indian Veterinary Research Institute, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.affiliation: Foreign Animal Disease Research Unit, USDA-ARS, Plum Island Animal Disease Center, Greenport, NY, USA.|PIADC Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA.
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-2074-3886
authors.initials: C
authors.lastname: Stenfeldt
authors.affiliation: UMN, STEMMA Laboratory, Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Perez
authors.affiliation: Foreign Animal Disease Research Unit, USDA-ARS, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Rodriguez
authors.affiliation: ICAR-Directorate of Foot and Mouth Disease, Mukteshwar, Nainital, Uttarakhand, India.
authors.forename: B
authors.initials: B
authors.lastname: Pattnaik
authors.affiliation: UMN, STEMMA Laboratory, Veterinary Population Medicine, University of Minnesota, St Paul, MN, USA.
authors.forename: K
authors.initials: K
authors.lastname: VanderWaal
authors.affiliation: Foreign Animal Disease Research Unit, USDA-ARS, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: J
authors.initials: J
authors.lastname: Arzt
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002353:Carrier State / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D005536:Foot-and-Mouth Disease / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007194:India / Q000453:epidemiology; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012367:RNA, Viral / Q000235:genetics; D016036:Seroepidemiologic Studies; D014611:Vaccination / Q000662:veterinary; D014614:Vaccines, Synthetic / Q000008:administration & dosage; D014765:Viral Vaccines / Q000008:administration & dosage
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines
keywords: FMD; India; carrier; foot-and-mouth; persistence; virus