Foot-and-Mouth Disease Impact on Smallholders - What Do We Know, What Don't We Know and How Can We Find Out More?

Abstract

Foot-and-mouth disease (FMD) endemic regions contain three-quarters of the world's FMD susceptible livestock and most of the world's poor livestock keepers. Yet FMD impact on smallholders in these regions is poorly understood. Diseases of low mortality can exert a large impact if incidence is high. Modelling and field studies commonly find high FMD incidence in endemic countries. Sero-surveys typically find a third of young cattle are sero-positive, however, the proportion of sero-positive animals that developed disease, and resulting impact, are unknown. The few smallholder FMD impact studies that have been performed assessed different aspects of impact, using different approaches. They find that FMD impact can be high (>10% of annual household income). However, impact is highly variable, being a function of FMD incidence and dependency on activities affected by FMD. FMD restricts investment in productive but less FMD-resilient farming methods, however, other barriers to efficient production may exist, reducing the benefits of FMD control. Applying control measures is costly and can have wide-reaching negative impacts; veterinary-cordon-fences may damage wildlife populations, and livestock movement restrictions and trade bans damage farmer profits and the wider economy. When control measures are ineffective, farmers, society and wildlife may experience the burden of control without reducing disease burden. Foot-and-mouth disease control has benefitted smallholders in South America and elsewhere. Success takes decades of regional cooperation with effective veterinary services and widespread farmer participation. However, both the likelihood of success and the full cost of control measures must be considered. Controlling FMD in smallholder systems is challenging, particularly when movement restrictions are hard to enforce. In parts of Africa this is compounded by endemically infected wildlife and limited vaccine performance. This paper reviews FMD impact on smallholders in endemic countries. Significant evidence gaps exist and guidance on the design of FMD impact studies is provided.

Keywords: Foot-and-mouth disease; economics; impact; serology; seroprevalence; smallholder.

Figure 1

Upper panel – May 2015 OIE global FMD status showing outbreaks in FMD‐free countries/zones that occurred between Jan 2005 and Jan 2016 ‐ map adapted from OIE FMD status map extracted 4th April 2016 from http://www.oie.int/en/animal-health-in-the-world/official-disease-status/fmd/en-fmd-carte/. Middle panel – global burden of FMD in cattle in 2008 (burden in sheep and goats has a similar distribution). Prevalence index based on estimates of incidence, population distribution and other risk factors, adapted from (Sumption et al., 2008). Note progress in South America since 2008 [compare with upper panel]. Lower panel – density of poor rural livestock keepers updated from Thornton et al. (2002). Central America, zones in Kazakhstan and Southern Africa, parts of South East Asia and some areas of South America are among the few exceptions where FMD is not present in poor livestock keeper populations.