Peste des petits ruminants (PPR) is caused by a Morbillivirus (Paramyxoviridae) that infects mostly goats and sheep. Discovered in Ivory Coast in 1942, this disease is now endemic in most African countries and has spread in Asia as far as India and China1. In immunologically naïve small ruminant populations, mortality rate is around 90% among younger animals, whilst it has milder effects on older ones. PPR has a devastating effect on the economies of low-income families. A live attenuated vaccine was developed in the 1980's, providing a life-long immunity after a single injection. The global eradication of PPR is now on the agenda of the Food and Agricultural Organization of the United Nations (FAO) and World Animal Health Organization (OIE) who play a pivotal role as they aim to reach this goal before 2030 ². Mobility of live animals is the most important factors in the diffusion and in maintaining the disease endemic in West Africa. It is a complex phenomenon involving different types of movements: small ruminants' trade among Western Africa countries (http://faostat.fao.org/); transhumance from arid areas of the North to greener areas in the South and sometimes crossing frontiers; religious festivity, like Tabaski during which millions of sheep are slaughtered. With this respect, Senegal and Mauritania have developed a system of animal health certificates to track livestock movements. These data allow researchers to re-construct the mobility network at the country level, and provides hint about animal movements across their borders. To describe PPR diffusion patterns, estimate its infectious burden, and assess the effects of PPR vaccination strategies we have been developing a metapopulation model for PPR in Mauritania and Senegal. We consider a network whose nodes correspond to administrative districts, and whose links represent the animal movements between two of them. The model couples the virus transmission and small ruminant population dynamics occurring at