Review of the status and control of foot and mouth disease in sub-Saharan Africa.

Six of the seven serotypes of foot and mouth disease (FMD) virus (i.e. all but Asia 1) are prevalent in Africa although there are marked regional differences in distribution. Three of these serotypes are unique to Africa, namely the three South African Territories (SAT) serotypes. Serotype C may also now be confined to Africa because it has not been reported elsewhere recently. In southern Africa at least, the SAT serotypes have an intimate and probably ancient association with African buffalo (Syncerus caffer) that is instrumental in their maintenance. Within each of the six prevalent serotypes, with the possible exception of C, there are a number of different lineages with more or less defined distributions (i.e. topotypes) that in some cases are sufficiently immunologically different from one another to require specific vaccines to ensure efficient control. This immunological diversity in prevalent serotypes and topotypes, in addition to uncontrolled animal movement in most parts of the continent, render FMD difficult to control in present circumstances. This fact, together with poorly developed intercontinental trade in animals and animal products has resulted in the control of FMD being afforded a low priority in most parts of the continent, although the northern and southern regions of the continent are an exception. As a consequence, eradication of FMD from Africa as a whole is not a prospect within the foreseeable future. In southern Africa, the use of fencing and other means to strictly control the movement of wildlife and livestock as well as judicious application of vaccine has resulted in countries of the region being able to access beef and other livestock markets in Europe and elsewhere in the developed world. Significant marketing of livestock and livestock products from Africa outside the continent is unlikely to be achieved unless similar approaches can be developed for other regions of Africa. This will result in continuing under-exploitation of a valuable resource in the arid and semi-arid regions of Africa, with increasing marginalisation of human populations living there.