Occurrence of Norovirus and Hepatitis A Virus RNA in Agricultural Soil from Produce Farms in Ohio and Georgia

Although foodborne viruses are considered ubiquitous in the environment, studies on their presence in soil are largely lacking. In this field study, 168 agricultural soil samples were collected from farms in Georgia and Ohio over seven and eight months, respectively. A total RNA isolation method was developed, and extracted genetic material was analyzed using reverse transcription quantitative PCR (RT-qPCR) to detect human norovirus and hepatitis A virus (HAV) RNA. Nearly 6% of samples (n = 10) tested positive for HAV RNA, while norovirus genogroup I and II were detected in 1.2% (n = 2) and 0.6% (n = 1) of samples, respectively. Despite samples being stored at −20 °C for an average of two years prior to testing, viruses remained detectable, although in low levels. CrAssphage DNA and pepper mild mottle virus (PMMoV) RNA were assessed as indicators of human fecal contamination in positive samples; however, neither was detected, precluding any correlation with the viral pathogens—likely due to differing characteristics between the indicators and target viruses. These findings provide valuable insight into the prevalence and diversity of foodborne viruses in agricultural soil and highlight its potential as a vehicle for virus transport to other matrices within a fresh produce farm environment.