Environmental Surveillance of Norovirus RNA in Restaurant Settings: Cleaning Materials as Primary Viral Reservoirs

BACKGROUND: Norovirus is the leading cause of viral gastroenteritis globally, with environmental persistence contributing significantly to transmission dynamics. Despite the recognized burden in the Middle East, systematic environmental surveillance data from restaurant settings remain critically limited, particularly regarding the role of cleaning materials as reservoirs for viruses. Middle East region. METHODS: A cross-sectional environmental surveillance study was conducted across 20 restaurants in Muscat and A'Sharqiyah regions, Oman (September 2020-August 2021). Forty environmental samples comprising 20 dishcloths and 20 tabletop swabs were collected from diverse restaurant types. Viral RNA was extracted using QIA amp Viral RNA MiniKit and analyzed using real-time RT-PCR following ISO/TS 15216-1:2017 protocols with genogroup-specific primers. RESULTS: Norovirus RNA was detected in 4 of 40 samples (10%, 95% CI: 2.8-23.7%) with higher prevalence on dishcloths (3/20, 15%, 95% CI: 3.2-37.9%) versus tabletops (1/20, 5%, 95% CI: 0.1-24.9%). All positive samples were genogrouped II with cycle threshold values of 31.8-36.2. Positive samples originated from three restaurants in high-traffic urban areas, with fast-food establishments showing the highest contamination. Field observations revealed substandard 41 sanitation practices, including frequent dishcloth reuse without disinfection. CONCLUSIONS: This paper fills a gap in the current body of knowledge by offering initial systematized evidence on norovirus contamination of the environment in restaurants within the Gulf region. The results indicate that cleaning things, especially the dishwasher cloths, are the main viral reservoirs, and the contamination rates are three times higher than food-containing surfaces. These results underscore the urgent need for enhanced sanitation protocols that specifically target cleaning implements rather than surfaces alone and emphasize the importance of routine environmental surveillance in understanding and interrupting norovirus transmission dynamics in food service settings.