Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 1993 May-Jun;149(3):207-23.
doi: 10.1016/S0007-1935(05)80168-X.

The carrier state in foot and mouth disease--an immunological review

Affiliations
Review

The carrier state in foot and mouth disease--an immunological review

J S Salt. Br Vet J. 1993 May-Jun.

Abstract

The carrier state in foot and mouth disease (FMD) is characterized by the asymptomatic low-level excretion of foot and mouth disease virus (FMDV) from the oropharynx of ruminants for periods that are species and virus strain-dependent. Persistent infection with FMDV readily occurs following the failure of virus elimination at the acute stage of infection, a process thought to be mediated through the phagocytosis of antibody/virus immune complexes. Recent evidence supports the view that carrier cattle are important in the epidemiology of FMD in the field. The absence of histopathological change in persistently infected tissues and the reduced cytopathology of carrier virus isolates in tissue culture suggest that less lytic FMDV variants are generated or selected in the carrier animal. Altered virus replication, due to attenuation or interference, rather than antigenic variation may therefore allow evasion of the exaggerated FMDV-specific systemic and local humoral immune responses that occur in the carrier state. Although cell-mediated immune mechanisms for FMDV clearance have not been described, the eventual elimination of many persistent virus infections involves this arm of the immune system. Thus, further investigation of cellular elements of the immune response, more particularly the local interaction of mononuclear cell infiltrates with persistently infected cells, represents an area of research that has the potential to elucidate the carrier state problem.

PubMed Disclaimer

Comment in

Substances

LinkOut - more resources