ABSTRACT Flow diagram showing sampling in Thailand, nucleic acid extraction, PMMoV qPCR detection, and comparison with ToBRFV and crAssphage across wastewater and animal feces. Pepper mild mottle virus (PMMoV) is one of the most abundant ribonucleic acid viruses in human feces and is widely used in wastewater-based epidemiology (WBE) and microbial source tracking. Its performance has not been evaluated in Thailand. This study analyzed archived nucleic acid extracts from sewage (n = 16), wastewater treatment plant (WWTP) influents (n = 16), and pooled animal feces (n = 35). PMMoV was detected in all sewage and WWTP samples, with concentrations of 4.26–5.83 log10 copies/100 mL in sewage (median 5.49) and 4.51–5.67 log10 copies/100 mL in WWTP influents (median 5.25). Only one pooled pig sample was positive (3.02 log10 copies/100 mg). PMMoV concentrations were higher than Tomato brown rugose fruit virus ToBRFV in sewage (p 0.001) and WWTP influents (p 0.05), and greater than crAssphage in WWTP influents (p 0.001). Correlation analysis showed positive associations with ToBRFV (Spearman′s rho = 0.57–0.62), crAssphage (rho = 0.29–0.59), and Escherichia coli (rho = 0.25–0.52). These findings demonstrate that PMMoV is abundant in Thai wastewater, rarely detected in pooled animal feces, and is suitable as a human-specific marker and WBE normalizer.
Paisantham et al. (Thu,) studied this question.