Nano-QuIC Enhanced CWD Detection in Norwegian Cervids

Chronic Wasting Disease (CWD) is a 100% fatal transmissible spongiform encephalopathy (TSE) in cervids. CWD has spread widely across North America and has been found in South Korea and Scandinavia. CWD is caused by the aggregation of misfolded, pathogenic prion proteins (PrP^Sc). Real-time quaking-induced conversion (RT-QuIC) assays are increasingly utilized for PrP^Sc detection. Our previous work on North American white-tailed deer lymph node demonstrated that Nanoparticle-Enhanced RT-QuIC (Nano-QuIC), a novel seed-amplification assay, can overcome endogenous inhibitors to increase assay sensitivity by tenfold and enhance reaction speed by 2.5-fold compared to RT-QuIC. Here, we examined the utility of Nano-QuIC CWD detection in Norwegian reindeer, moose, and red deer. Previous research has shown that diverse Scandinavian CWD strains are distinct from North American strains. We performed Nano-QuIC and RT-QuIC assays in parallel on lymph node, brain, and skin samples from 18 CWD-detected and 15 CWD-not-detected Scandinavian cervids, confirmed by ELISA and Western Blot. For both assays, PrP^Sc was consistently detected in brain tissue across species. Ongoing research indicates consistent  detection in reindeer and red deer lymph nodes but not skin; while moose skin shows consistent detection, but variable detection in lymph node. Similar to white-tailed deer, Nano-QuIC was tenfold more sensitive across species in lymph node and brain, and increased reaction speed in some isolates. Increased sensitivity allows for potential CWD detection in earlier or preclinical stages of disease. These preliminary results demonstrate that Nano-QuIC and RT-QuIC can effectively detect CWD across a diverse range of Scandinavian species, strains, and tissues.