Contamination of contact surfaces with SARS-CoV-2 has been reported as a potential route for the transmission of COVID-19. This could be a major issue in developing countries where access to basic sanitation is poor, leading to the sharing of toilet facilities. In this study, we report SARS-CoV-2 contamination of key contact surfaces in shared toilets and the probabilistic risks of COVID-19 infections based on detection and quantification of the nucleic acid on the surfaces. We observed that 54–69% of the contact surfaces were contaminated, with SARS-CoV-2 loads ranging from 28.1 to 132.7 gene copies per cm 2 . Toilet seats had the highest contamination, which could be attributed to shedding of the virus in feces and urine. We observed a significant reduction in viral loads on the contaminated surfaces after cleaning, showing the potential of effective cleaning on the reduction of contamination. The pattern of contamination indicates that the most contaminated surfaces are those that are either commonly touched by users of the shared toilets or easily contaminated with feces and urine. These surfaces were the toilet seats, cistern handles and tap handles. The likelihood (probability) of infection with COVID-19 on these surfaces was highest on the toilet seat (1.76 × 10 −4 (1.58 × 10 −6 )) for one time use of the toilet. These findings highlight the potential risks for COVID-19 infections in the event that intact infectious viral particles are deposited on these contact surfaces. Therefore, this study shows that shared toilet facilities in densely populated areas could lead to an increase in risks of COVID-19 infections. This calls for the implementation of risk reduction measures, such as regular washing of hands with soap, strict adherence to wearing face masks, and effective and regular cleaning of shared facilities.

Shared sanitation is widely proposed as a means to increase access to improved sanitation. There are few reports of a causal relationship between the use of shared sanitation and community-acquired diarrhoea. This paper presents an analytical review of studies that have investigated the relationship between the use of shared sanitation and the prevalence of (1) diarrhoeal disease and (2) soil-transmitted helminth (STH) infections. Data were extracted from the reviewed literature to calculate odds ratios (ORs) and confidence intervals (CIs). The use of shared sanitation showed a significant increase in diarrhoeal diseases, with an overall OR of 2.39 (85% CI 1.15–8.31). Children under 5 years were slightly less affected with a prevalence ratio of 1.09 (95% CI 1.06–1.12). The number of published reports on STH infections in relation to shared sanitation was limited, but the few that do exist report on ‘improved sanitation’, showing a positive and protective impact with an overall OR of 0.49 (95% CI 0.28–0.89), which is contrary to the negative impact related to diarrhoea. Despite the limited information on the direct link between shared sanitation and incidence of diarrhoeal/STH infections, this literature review demonstrates that the relationship deserves close attention in future practice and research. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

Contamination of contact surfaces with SARS-CoV-2 has been reported as a potential route for the community transmission of COVID-19. This could be a major issue in developing countries where access to basic sanitation is poor leading to the sharing of toilet facilities. In this study, we present the first report of SARS-CoV-2 contamination on key contact surfaces in shared toilets, in the city of Durban, using droplet digital PCR and assessed the probabilistic risks of COVID-19 infections.Approximately, 53-69% of the contact surfaces were contaminated, with SARS-CoV-2 viral loads per cm2 ranging from 25.9 to 132.69 gc/cm2. Toilet seats had the highest contamination per cm2. The results suggested that the leading cause of contamination in shared toilets could be the shedding of the viral particles in feces and contaminated hands. We observed a significant reduction in viral loads on the contaminated surfaces after cleaning, showing the potential of effective cleaning on the reduction of contamination of these surfaces. The probabilistic assessment showed a high potential for COVID-19 infections. Touching the internal latch of the toilet cubicle had the highest risk of infections (4.3x10-2(6.0x10-4)) when a person uses the toilet once in a day, increasing to 1.0x10-1(1.4x10-3) for three uses in a day. The risks estimated in this study were higher than any of the tolerable/acceptable risk figures proposed for COVID-19 from environmental exposure. This calls for the implementation of risk reduction measures, such as strict adherence to wearing face masks, regular washing of hands with soap, and effective and regular cleaning.

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