Tomato Brown Rugose Fruit Virus (ToBRFV): A Better Indicator of Viral Load and Treatment Efficacy of Wastewater Treatment.

Abstract This study investigated the occurrence of Tomato brown rugose fruit virus (ToBRFV) and Pepper mild mottle virus (PMMoV) as well bacteriophages (e.g., Escherichia MS2 and BZ13 virus) in untreated wastewater and evaluated their potential as viral indicators and surrogates to assess water quality during treatment. ToBRFV was quantified by RT-qPCR and identified by whole genome sequencing using two diagnostic sample processing methods: an RVP panel and a virus enrichment method. Our study found that both methods revealed a high abundance of ToBRFV in the wastewater samples from the largest collection area site, Truckee Meadows water reclamation facility (TMWRF). Notably, ToBRFV was present at much higher levels than PMMoV and Escherichia MS2/BZ13 viruses and was consistently at high levels across the 12-month study period. This pattern was also observed in two other Water Reclamation Facilities and three sub-sewershed sample collection sites (sub-neighborhoods, travel-influenced sites, and elementary schools). We demonstrated that ToBRFV is a more effective viral indicator than PMMoV and bacteriophages (i.e., coliphages) and recommend its use as a marker for water quality and treatment efficacy evaluation.