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

## TL;DR

This study finds that cleaning materials, especially dishcloths, are major sources of Norovirus contamination in restaurants in the Gulf region, highlighting the need for improved sanitation practices.

## Contribution

The study provides the first systematic evidence of Norovirus contamination in restaurant cleaning materials in the Gulf region.

## Key findings

- Norovirus RNA was detected in 10% of restaurant environmental samples, with 15% contamination in dishcloths.
- All positive samples belonged to the highly transmissible Genogroup II of Norovirus.
- Fast-food restaurants in urban areas showed the highest contamination rates.

## Abstract

Public health relevance—How does this work relate to a public health issue?
This study addresses the prevalence of Norovirus, a leading cause of viral gastroenteritis, within the food service environment. An environmental surveillance data for Norovirus contamination in restaurants within the Gulf region.

This study addresses the prevalence of Norovirus, a leading cause of viral gastroenteritis, within the food service environment. An environmental surveillance data for Norovirus contamination in restaurants within the Gulf region.

Public health significance—Why is this work of significance to public health?
Revealed a 10% contamination rate in restaurants, with all positive samples identified as the highly transmissible Genogroup II using ISO 15216-1 protocols.Identified cleaning materials as primary viral reservoirs, with dishcloths showing a 3-fold higher contamination rate (15%) compared to tabletops (5%).

Revealed a 10% contamination rate in restaurants, with all positive samples identified as the highly transmissible Genogroup II using ISO 15216-1 protocols.

Identified cleaning materials as primary viral reservoirs, with dishcloths showing a 3-fold higher contamination rate (15%) compared to tabletops (5%).

Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?
Highlights a critical need for policymakers to mandate stricter sanitation protocols, as poor cleaning practices directly correlate with higher viral detection.Practitioners should prioritize the management of “secondary transfer” risks, specifically moving from reusable cloths to single-use or high-disinfection cleaning methods to eliminate reservoirs.

Highlights a critical need for policymakers to mandate stricter sanitation protocols, as poor cleaning practices directly correlate with higher viral detection.

Practitioners should prioritize the management of “secondary transfer” risks, specifically moving from reusable cloths to single-use or high-disinfection cleaning methods to eliminate 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.