A protocol for mapping Blastocystis epidemiology and diagnostics from One Health perspective

<ns3:p> <ns3:italic>Blastocystis</ns3:italic> is a globally prevalent gut protist colonising over a billion people worldwide, yet its epidemiology, transmission dynamics, and clinical significance remain underexplored. This protocol represents the first step of a large-scale effort to map <ns3:italic>Blastocystis</ns3:italic> epidemiology and diagnostic practices across Europe through the COST Action CA21105: <ns3:italic>Blastocystis under One Health</ns3:italic> . By assessing diagnostic methodologies across clinical, veterinary, and environmental sectors, this work sets the foundation for future research and standardisation. Here, we highlight key findings, challenges, and a roadmap for improving <ns3:italic>Blastocystis</ns3:italic> detection, ultimately influencing global health policies and microbial ecology studies. </ns3:p>