title: Detection of Foot-and-mouth Disease Virus RNA and Capsid Protein in Lymphoid Tissues of Convalescent Pigs Does Not Indicate Existence of a Carrier State.
abstract: A systematic study was performed to investigate the potential of pigs to establish and maintain persistent foot-and-mouth disease virus (FMDV) infection. Infectious virus could not be recovered from sera, oral, nasal or oropharyngeal fluids obtained after resolution of clinical infection with any of five FMDV strains within serotypes A, O and Asia-1. Furthermore, there was no isolation of live virus from tissue samples harvested at 28-100 days post-infection from convalescent pigs recovered from clinical or subclinical FMD. Despite lack of detection of infectious FMDV, there was a high prevalence of FMDV RNA detection in lymph nodes draining lesion sites harvested at 35 days post-infection, with the most frequent detection recorded in popliteal lymph nodes (positive detection in 88% of samples obtained from non-vaccinated pigs). Likewise, at 35 dpi, FMDV capsid antigen was localized within follicles of draining lymph nodes, but without concurrent detection of FMDV non-structural protein. There was a marked decline in the detection of FMDV RNA and antigen in tissue samples by 60 dpi, and no antigen or viral RNA could be detected in samples obtained at 100 dpi. The data presented herein provide the most extensive investigation of FMDV persistence in pigs. The overall conclusion is that domestic pigs are unlikely to be competent long-term carriers of infectious FMDV; however, transient persistence of FMDV protein and RNA in lymphoid tissues is common following clinical or subclinical infection.
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.|Oak Ridge Institute for Science and Education, PIADC Research Participation Program, Oak Ridge, TN, USA.
authors.forename: C
authors.initials: C
authors.lastname: Stenfeldt
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Pacheco
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: G R
authors.initials: GR
authors.lastname: Smoliga
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: E
authors.initials: E
authors.lastname: Bishop
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Pauszek
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Hartwig
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Rodriguez
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Greenport, NY, USA.
authors.forename: J
authors.initials: J
authors.lastname: Arzt
mesh_terms: D000818:Animals; D036022:Capsid Proteins / Q000032:analysis; D002353:Carrier State / Q000821:virology; D005536:Foot-and-Mouth Disease / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000302:isolation & purification*; D008221:Lymphoid Tissue / Q000821:virology; D009960:Oropharynx / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology
chemical_list: D036022:Capsid Proteins; D012367:RNA, Viral
keywords: FMD, FMDV, virus; carriers; foot-and-mouth disease; persistence; pigs