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
. 2002 Dec;21(3):519-29.
doi: 10.20506/rst.21.3.1366.

Unapparent foot and mouth disease infection (sub-clinical infections and carriers): implications for control

P Sutmoller  1 , Olascoaga R Casas
Affiliations
Free article
Review

Unapparent foot and mouth disease infection (sub-clinical infections and carriers): implications for control

P Sutmoller et al. Rev Sci Tech. 2002 Dec.
Free article

Abstract

Unlike animals which are carriers of foot and mouth disease (FMD), sub-clinically infected animals may be highly contagious. The implications of sub-clinical infections for the control of FMD are serious because such animals are likely to disseminate the disease when in contact with susceptible livestock. Recent dissemination of FMD virus (FMDV) in Europe shows that sub-clinically infected animals render trade in animals or animal products a potential risk for importing countries. This clearly demonstrates that the paradigm 'free of FMD without vaccination' is not synonymous with 'risk-free'. The risk of introduction of subclinical FMD into FMD-free countries may increase significantly, with the occurrence of large susceptible animal populations, changed agricultural practices, expansion of trade in live animals and animal movements, increased trade in animal products and greater mobility of people. Such changes in circumstances require that national and international authorities remain continuously vigilant to determine any altered risk for importation of FMD. A few historical reports and some recent observations in southern Africa indicate the possibility of dissemination of FMD by bovine carriers into herds of susceptible cattle. These reports have greatly influenced FMD trade policies and thus, FMD control and eradication strategies. However, other field evidence does not support this claim and several controlled experiments were unable to show that carriers are able to initiate disease. When millions of cattle were systematically vaccinated with good quality vaccines, FMD disappeared in spite of a large sentinel population in the form of calves and unvaccinated sheep and pigs. A low number of carriers most likely persisted, but they did not hamper the eradication of the disease. Vaccination policies and trade regulation must be based on risk assessments taking these factors into consideration.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

MeSH terms

-