Perspectives on progression of transboundary disease, one health and ecosystem health management in the Greater Mekong Subregion and beyond

Abstract

Livestock production in the Greater Mekong Subregion (GMS) reflects the inefficient smallholder ‘keeper’ system that has been slow to adapt to the rapidly expanding demand for animal proteinsourced foods in the region as urban economies have flourished and food preferences altered. The prolonged surge in demand, with only modest increases in local production, has increased the movement of animals and products into and from the GMS, accompanied by surging risks of transboundary animal disease (TAD) incursions, including the one health (OH) threats of zoonoses and antimicrobial resistance. As a consequence, the region has been subjected to epidemics of highly pathogenic avian influenza (HPAI), new strains of foot-and-mouth disease (FMD) virus, with recent incursions of African swine fever (ASF), lumpy skin disease (LSD), porcine reproductive and respiratory syndrome (PRRS) and risks of peste petits ruminants (OPR) occurring in Southeast Asia (SEA) and beyond. These incidents reflect inadequate biosecurity, a sustainability issue that was clearly of relevance in the covid-19 pandemic, reflecting ecosystem health (EH) deficits, including land-use issues and unregulated trading in wildlife-sourced and poorly processed foods through the predominant ‘wet markets’. These challenges are increasingly confounded by slow adaption to the impacts of the climate crisis, including flooding, drought, crop failures and hypothermia episodes. The increase in animal and product movements enhances disease transmission risk, yet coincides with emerging concerns of greenhouse-gas emissions (GHGe) from livestock production, especially from large ruminants, as the world attempts to find pathways in managing the climate crisis. Despite the prolonged collaborative efforts of the SEA China FMD program from 1997 to 2023, a recent review confirmed persistent deficits in biosecurity, vaccine resourcing, disease surveillance, engagement of farmers, and national emergency disease-response capacities. A major project is about to fund major improvements in livestock value chains in Cambodia, including more effective biosecurity, surveillance and emergency disease-response capacities for TADs, antimicrobial resistance (AMR) and zoonoses. Similarly, a private-sector investment in Laos has developed a more climate-resilient livestock-feeding system that decreases GHGe impacts from ruminant production. These developments are likely to extend beyond both countries and be potentially transformational for the livelihoods of many of the poorest citizens in the region.