The Weller Lab investigates emerging viral and microbial pathogens relevant to food safety, agriculture, environmental reservoirs, and human disease. We develop molecular, sequencing, and diagnostic approaches to identify newly recognized pathogens, characterize their reservoirs and transmission pathways, and support surveillance and risk assessment. Our research includes unconventional hepatitis delta virus (HDV) and related circular RNA agents, including HDV associated with Sjögren’s disease. We are particularly interested in translating pathogen discovery into practical detection tools for food, agricultural, and public health applications.