Sample collection
Sampling was conducted between 2017 and 2018 in 18 states in total (Figure 1 and Table S1 in supplementary materials). Veterinarians of national veterinary services conducted the field studies in accordance with local legislation, approval (AEC/02/87/20) was provided by the NVRI Animal Ethics Committee. Still, the tissues used in the study were sourced ethically. In one major market per state, goats and sheep suspected of acute PPR infection were identified based on clinical symptoms that included fever over 40 °C, weight loss, ocular, nasal, or ocular-nasal discharge and diarrhoea. The suspected animals were bought from their owners, euthanized humanely, and subjected to an autopsy to collect tissue samples (lungs and mesenteric lymph nodes). In addition, samples were collected in slaughter houses located near the market from carcasses showing visible symptoms of diarrhoea and oculo-nasal discharges on their carcasses. The samples are then quickly transported to the PPR laboratory of the National Veterinary Research Institute, Vom, Nigeria and placed in a freezer at -70 °C before visiting another new state. The samples were then subsequently shipped to CIRAD, Montpellier, France for further analysis in a Biosafety level-3 laboratory facility.