Options for control of foot-and-mouth disease: knowledge, capability and policy

Abstract

Foot-and-mouth disease can be controlled by zoo-sanitary measures and vaccination but this is difficult owing to the existence of multiple serotypes of the causative virus, multiple host species including wildlife and extreme contagiousness. Although intolerable to modern high-production livestock systems, the disease is not usually fatal and often not a priority for control in many developing countries, which remain reservoirs for viral dissemination. Phylogenetic analysis of the viruses circulating worldwide reveals seven principal reservoirs, each requiring a tailored regional control strategy. Considerable trade benefits accrue to countries that eradicate the disease but as well as requiring regional cooperation, achieving and maintaining this status using current tools takes a great deal of time, money and effort. Therefore, a progressive approach is needed that can provide interim benefits along the pathway to final eradication. Research is needed to understand and predict the patterns of viral persistence and emergence and to improve vaccine selection. Better diagnostic methods and especially better vaccines could significantly improve control in both the free and the affected parts of the world. In particular, vaccines with improved thermostability and a longer duration of immunity would facilitate control and make it less reliant on advanced veterinary infrastructures.

Figure 1.

Conjectured national FMD status in 2008 overlaid with regional FMDV pools and predominant virus serotypes (asterisk, types O and A also in pool 6 where it overlaps pool 4). Adapted from FMD World Reference Laboratory (http://www.wrlfmd.org/). For official information on country status, see http://www.oie.int/wahid-prod/public.php?page=home.

Figure 2.

Pathway for progressive FMD control. Stages 0–3, infected countries/zones.