Genetic Evidence for Transboundary Circulation of Peste Des Petits Ruminants Across West Africa

Abstract

Peste des Petits Ruminants (PPR) is a viral disease affecting predominantly small ruminants. Due to its transboundary nature, regional coordination of control strategies will be key to the success of the on-going PPR eradication campaign. Here, we aimed at exploring the extent of transboundary movement of PPR in West Africa using phylogenetic analyses based on partial viral gene sequences. We collected samples and obtained partial nucleoprotein gene sequence from PPR-infected small ruminants across countries within West Africa. This new sequence data was combined with publically available data from the region to perform phylogenetic analyses. A total of fifty-five sequences were obtained in a region still poorly sampled. Phylogenetic analyses showed that the majority of virus sequences obtained in this study were placed within genetic clusters regrouping samples from multiple West African countries. Some of these clusters contained samples from countries sharing borders. In other cases, clusters grouped samples from very distant countries. Our results suggest extensive and recurrent transboundary movements of PPR within West Africa, supporting the need for a regional coordinated strategy for PPR surveillance and control in the region. Simple phylogenetic analyses based on readily available data can provide information on PPR transboundary dynamics and, therefore, could contribute to improve control strategies. On-going and future projects dedicated to PPR should include extensive genetic characterization and phylogenetic analyses of circulating viral strains in their effort to support the campaign for global eradication of the disease.

Peste des Petits Ruminants at the Wildlife–Livestock Interface in the Northern Albertine Rift and Nile Basin, East Africa

“…Our results confirm that PPRV strains from DRC in October 2017 were identical to the lineage III strains that emerged subsequently in Burundi in December 2017 [50]. These results further indicate that national borders are highly porous for disease spread and that PPR outbreaks in East Africa can easily occur on a transboundary basis [51,52]. This transboundary spread is most likely triggered by formal and/or informal movements of small ruminants.…”

Peste des petits ruminants in Africa: a review of currently available molecular epidemiological data, 2020

“…This highlighted the results of livestock movement from Mauritania to countries to the south. This observation was recently confirmed by Tounkara et al [30] (GenBank no. MK777900; Fig.…”

“…4). A more recent study included the analysis of eleven samples from goats in Mali [30]. One of the samples was collected in 1999, while the remaining 10 were ocular swabs collected in 2014.…”

“…4 ). Tounkara et al [ 30 ] have recently analysed five partial N gene sequences generated from samples collected from goats and sheep in Burkina Faso in 2008 and 2014. All of the sequences belonged to viruses of lineage II.…”

Combining viral genetic and animal mobility network data to unravel peste des petits ruminants transmission dynamics in West Africa

“…PPR is now the target of a global eradication campaign led by the World Animal Health Organisation (OIE) and the Food and Agriculture Organisation (FAO) [ 5 ]. Despite the availability of efficient and cheap vaccines against PPR, control of this disease is complicated, notably because of extensive movement of animals through within- and trans-boundary trade, and seasonal transhumance, which is often poorly monitored in regions where PPR is endemic [ 6 , 7 ]. For example, importing infected sheep from abroad for the purpose of fattening was at the origin of the re-emergence of PPR in Morocco in 2015 just a few years after the disease had been completely eradicated [ 8 ].…”