Incidence and Distribution of Foot-and-Mouth Disease in Asia, Africa and South America; Combining Expert Opinion, Official Disease Information and Livestock Populations to Assist Risk Assessment

Abstract

Risk assessment procedures frequently require quantitative data on the prevalence of the disease in question. Although most countries are members of the World Organization for Animal Health (OIE), the importance attached to foot-and-mouth disease (FMD) reporting or surveillance for infection varies enormously between infected countries. There is a general consensus that FMD outbreaks in endemic countries are greatly under-reported, to a degree related either to the economic or the political development level of the country. This exploratory study was first undertaken by FAO, but thereafter extended and reviewed by the working group on FMD risk co-ordinated by the European Food Safety Authority (EFSA). The paper attempts to overcome the lack of reporting through using expert opinion to extrapolate incidence indices from countries considered to have 'representative' levels of FMD. These were combined with livestock density distributions to provide maps of prevalence indices, which were found to be highest in China (pigs), India (cattle), the Near East (small ruminants) and the Sahel (small ruminants and cattle). Similar patterns were found when weighted expert rankings of a range of additional ranked disease parameters were also produced, and then combined with susceptible animal densities to produce a weighted multi-species density. Results suggest that the methods can provide useful information at both national and sub-national resolution, even for countries for which quantitative FMD data is currently unavailable: two of the regions identified provide little or no data on a regular basis to the OIE and therefore may be overlooked if the level of officially reported FMD is only used. As the estimated prevalences are based on recent disease history and expert opinion, they are most likely to be inaccurate where FMD incursions are infrequent as a result of the preventive measures and geographical and trade isolation. This study, therefore, highlights the need for specific detailed country risk assessments where livestock trade is under consideration. Validating the approach including ground truthing, will require collaboration between a number of agencies and institutions, in critical countries, particularly those with high disease burdens that share borders or trade livestock with currently FMD-free nations.

A retrospective study on the epidemiology of foot-and-mouth disease in Bhutan

“…However, the findings of this study needs to be interpreted with caution because of the likely bias of underreporting of cases and outbreaks which is inherent in a passive surveillance system (McLeod 2003;Sumption et al 2008;Thrusfield 2005). The biases occurring from nonreporting of sub-clinical cases are expected to be low given the fact that cattle are the predominant species in Bhutan and the clinical signs are more discernible in this species compared to other FMD-susceptible species (Davies 2002).…”

Foot and mouth disease virus vaccines

“…The last decade has seen a renewed public and political interest on foot and mouth disease (FMD) due to its potential as a bio-terrorist threat and some high-profile disease incursions in previously FMD-free countries in Asia, Europe and South America [1,2]. Control methods varied among these regions but the ultimate result was the demise of millions of animals, the loss of billions of US$ in various economic activities including tourism, agriculture and trade and serious social impacts [3].…”

Haemato-Biochemical Aspects of Foot and Mouth Disease in Cattle in Chittagong, Bangladesh

“…FMDV may circulate undetected in vaccinated herds and in some indigenous breeds in areas in which FMD is common (Kitching, 2002). Frequent outbreaks noticed around the globe since the first outbreak of FMD in America in 1870 (Sumption et al, 2008;Gibbs, 2003). Due to the infection of FMDV, the livestock industry faces severe economic losses by mortality in young animals and morbidity in adult.…”