Environmental surveillance of surface contamination is an unexplored tool for understanding transmission of SARS-CoV-2 in community settings. We conducted longitudinal swab sampling of high-touch non-porous surfaces in a Massachusetts town during a COVID-19 outbreak from April to June 2020. Twenty-nine of 348 (8.3%) surface samples were positive for SARS-CoV-2 RNA, including crosswalk buttons, trash can handles, and door handles of essential business entrances (grocery store, liquor store, bank, and gas station). The estimated risk of infection from touching a contaminated surface was low (less than 5 in 10,000) by quantitative microbial risk assessment, suggesting fomites play a minimal role in SARS-CoV-2 community transmission. The weekly percentage of positive samples (out of n = 33 unique surfaces per week) best predicted variation in city-level COVID-19 cases with a 7-day lead time. Environmental surveillance of SARS-CoV-2 RNA on high-touch surfaces may be a useful tool to provide early warning of COVID-19 case trends.

Environmental surveillance of surface contamination is an unexplored tool for understanding transmission of SARS-CoV-2 in community settings. We conducted longitudinal swab sampling of high-touch non-porous surfaces in a Massachusetts town during a COVID-19 outbreak from April to June 2020. Twenty-nine of 348 (8.3 %) surface samples were positive for SARS-CoV-2, including crosswalk buttons, trash can handles, and door handles of essential business entrances (grocery store, liquor store, bank, and gas station). The estimated risk of infection from touching a contaminated surface was low (less than 5 in 10,000), suggesting fomites play a minimal role in SARS-CoV-2 community transmission. The weekly percentage of positive samples (out of n=33 unique surfaces per week) best predicted variation in city-level COVID-19 cases using a 7-day lead time. Environmental surveillance of SARS-CoV-2 RNA on high-touch surfaces could be a useful tool to provide early warning of COVID-19 case trends.

No abstract

Enteric pathogen infections are a leading cause of morbidity and mortality globally, with the highest disease burden in low-income countries. Hands act as intermediaries in enteric pathogen transmission, transferring enteric pathogens between people and the environment through contact with fomites, food, water, and soil. In this study, we conducted a systematic review of prevalence and concentrations of fecal indicator microorganisms (i.e., E. coli, fecal coliform) and enteric pathogens on hands. We identified 84 studies, reporting 35,440 observations of hand contamination of people in community or household settings. The studies investigated 44 unique microorganisms, of which the most commonly reported indicators were E. coli and fecal coliforms. Hand contamination with 12 unique enteric pathogens was reported, with adenovirus and norovirus as the most frequent. Mean E. coli prevalence on hands was 62% [95% CI 40%–82%] and mean fecal coliform prevalence was 66% [95% CI 22%–100%]. Hands were more likely to be contaminated with E. coli in low/lower-middle-income countries (prevalence: 69% [95% CI 48%–88%]) than in upper-middle/high-income countries (6% [95% CI 2%–12%]). The Review also highlights the importance of standardizing hand sampling methods, as hand rinsing was associated with greater fecal contamination compared to other sampling methods.

Enteric pathogen infections are a leading cause of morbidity and mortality globally, with the highest disease burden in low-income countries. Hands act as intermediaries in enteric pathogen transmission, transferring enteric pathogens between people and the environment through contact with food, water, and soil. In this study, we conducted a systematic review of prevalence and concentrations of fecal indicator microorganisms (i.e., E. coli, fecal coliform) and enteric pathogens on hands. We identified eighty studies, reporting 31,305 observations of hand contamination of people in community or household settings. The studies investigated 45 unique microorganisms, of which the most commonly reported indicators were E. coli and fecal coliforms. Hand contamination with 14 unique enteric pathogens was reported, with adenovirus and rotavirus as the most frequent. Mean E. coli prevalence on hands was 40% [95% CI 18%-62%] and mean fecal coliform prevalence was 42% [95% CI 16%-69%]. Hands were more likely to be contaminated with E. coli in low/lower-middle-income countries (prevalence: 49% [25% - 72%]) than in upper-middle/high-income countries (6% [1% - 12%]). In low/lower-middle income countries, E. coli prevalence was higher in urban compared to rural settings (52% mean prevalence in urban versus 33% in rural), although substantial heterogeneity between studies limited confidence in this finding. The review also highlighted the importance of standardizing hand sampling methods, as hand rinsing was associated with greater fecal contamination compared to other sampling methods.