Understanding the global distribution of atypical porcine pestivirus (APPeV).

Atypical porcine pestivirus (APPeV) is a pestivirus affecting pigs, notably causing high mortality in piglets due to neurological issues that impair suckling. This study reviews global literature from 2015 to March 2024, assessing APPeV prevalence. Analysing 40 relevant articles, it finds APPeV widely distributed across Europe, South America, North America, and Asia, with minimal presence in Africa and Australia. The scarcity in these regions might be due to geographical isolation, environmental factors, limited surveillance, diagnostics, or under-reporting. China leads in APPeV prevalence reports, followed by the USA, Germany, Sweden, and other countries. The main diagnostic methods are quantitative reverse transcription polymerase chain reaction (RT-qPCR) and RT-PCR, using tissue and serum samples. APPeV detection in the serum of boars and wild boars suggests possible persistent infections, indicating their role in APPeV epidemiology. Given the global outbreaks, particularly of congenital tremor (CT), the study calls for expanded research, especially in under-studied regions like Africa and Australia, focusing on healthy pigs, CT-affected piglets, and boars to better understand APPeV transmission dynamics.