Changes in environmental conditions alter host-parasite interactions, raising the need for effective epidemiological surveillance. Developing operational, accurate, and cost-effective methods to assess individual infection status and potential for pathogen spread is a prerequisite to anticipate future disease outbreaks in wild populations. For endoparasites, effective detection of infections usually relies on host-lethal approaches, which are barely compatible with wildlife conservation objectives. Here, we used the brown trout (Salmo trutta) - Tetracapsuloides bryosalmonae host-parasite system to develop...