A novel coronavirus emerged in Wuhan, China in late 2019. The novel coronavirus, SARS-CoV-2 (or COVID-19), is believed to have originated in bats, and has rapidly progressed to a global pandemic that has infected hundreds of thousands of individuals (1, 2).
Author: Dr. Michael B. Fisher, University of North Carolina at Chapel Hill. Acknowledgement to Dr. Mark Sobsey for critical review and input.
Ensuring adequate water, sanitation, and hygiene measures is essential to controlling the spread of COVID-19 (1), but much remains unknown with respect to the optimizing and quantifying the impacts of WaSH interventions and best practices in combating the current COVID-19 pandemic.
Water and Hygiene
Adequate hand and personal hygiene prevent COVID-19 transmission. Handwashing with soap (3) or alcohol-based hand sanitizer (4) is an effective means to disrupt transmission, along with social distancing, identification and isolation of cases, contact tracing and follow-up, etc. Adequate quantities of available water are essential to maintaining hand hygiene and personal hygiene (5). While these universal prevention measures are well-known, the relative impact of hand hygiene as compared to other infection prevention and control measures such as social distancing, surface disinfection, etc., as a means of slowing COVID-19 transmission has not yet been characterized. However, the availability of water and cleaning products such as soap and chlorine are essential for basic hygiene and infection prevention measures such as hand washing, surface disinfection, and laundry, and should be regarded as universal prerequisites for effective control of the COVID-19 pandemic and other outbreaks (1).
Waterborne transmission has not been documented, and the survival of COVID-19 in water remains unknown (but the virus is thought to persist for hours to days); however, WHO advises that waterborne transmission is unlikely based on available evidence for other similar viruses, and current best practices for safe management of drinking water should be sufficient during the COVID-19 outbreak (1). In addition to direct waterborne transmission, person-to-person transmission may be a concern at communal water sources, where crowding may lead to direct and indirect contact between individuals. Guidelines for practicing appropriate social distancing while accessing communal water sources have not yet been developed, but general social distancing and hand hygiene guidelines may be applicable here as well. The extent to which communal water sources may be hotspots for person-to-person COVID-19 transmission is currently unknown.
The persistence of COVID-19 on surfaces and hands under different environmental conditions is being actively studied. Available evidence suggests that the virus can likely persist and remain infectious for up to 3 days on many surfaces (6). Chlorine rapidly inactivates COVID-19 and other viruses on contact. Current recommendations indicate that a dilute chlorine solution (e.g. 0.1% free chlorine, which can be prepared by adding one part household bleach [~5% free chlorine] to 49 parts water- i.e. 20 mL of bleach per liter, 7) or a 70% ethyl alcohol solution can be used for surface disinfection at least once per day (1, 8). However, further validation of best practices for optimal surface disinfection and optimal cleaning frequencies to prevent COVID-19 transmission may be useful to review and/or refine this guidance.
COVID-19 RNA has been detected in the feces of infected individuals (9), but it is not yet known whether infectious virus is also shed in feces. Furthermore, the survival of COVID-19 in feces and wastewater has not yet been characterized. To date, transmission of the virus via feces/wastewater has not been documented, and risk of transmission by this pathway is believed to be relatively low (10). Current WHO recommendations on safe management of human excreta are therefore currently deemed sufficient for preventing fecal-oral transmission of COVID-19. However, where sanitation facilities are shared between known COVID-19 cases and those without symptoms, additional precautions may be warranted- specifically, the facilities should be disinfected at least twice daily by a trained worker wearing suitable personal protective equipment (PPE, 1). Furthermore, adequate plumbing of flush toilets is needed to prevent backflow and/or aerosolization of excreta, which may contribute to COVID-19 transmission by aersosols (1). Where these recommendations are not implemented, the extent to which unsafe management of excreta may contribute to COVID-19 transmission has not yet been quantified. Furthermore, the extent to which sanitation workers may be at risk from transmission of COVID-19 through the feces of infected persons likewise remains unknown. The use of PPE and frequent handwashing should reduce risks to sanitation workers; where latrines that may contain excreta from infected individuals must be emptied, hydrated lime may be added to disinfect the excreta prior to emptying (1).
While available evidence is sufficient to reinforce the need for adequate water, sanitation, hygiene, and cleaning services and methods to prevent COVID-19 transmission in homes, communities, and health care facilities, many important questions still remain unanswered.
- How is your organization confronting the current COVID-19 pandemic?
- Are you involved in work to answer any of these WaSH-related questions?
- What next steps are needed to inform efforts by rural water supply implementers and rural environmental health professionals to combat the current coronavirus pandemic?
- What additional monitoring activities (if any) are needed for an effective COVID-19 response where you work?
Share your responses by joining the RWSN e-discussion: Responding to the current COVID-19 crisis: questions, resources, and implications for rural water supply at the operational level
1. World Health Organization. (2020). Water, sanitation, hygiene and waste management for COVID-19: technical brief, 03 March 2020 (No. WHO/2019-NcOV/IPC_WASH/2020.1). World Health Organization. https://globalhandwashing.org/wp-content/uploads/2020/03/WHO-2019-NcOV-IPC_WASH-2020.1-eng-5.pdf
2. Perlman, S. (2020). Another decade, another coronavirus. https://www.nejm.org/doi/full/10.1056/NEJMe2001126
3. Centers for Disease Control and Prevention. (2020). Interim infection prevention and control recommendations for patients with confirmed 2019 novel coronavirus (2019-nCoV) or persons under investigation for 2019-nCoV in healthcare settings. https://www.cdc.gov/coronavirus/2019-ncov/infection-control/control-recommendations.html
4. Siddharta, A., Pfaender, S., Vielle, N. J., Dijkman, R., Friesland, M., Becker, B., … & Brill, F. H. (2017). Virucidal activity of WHO-recommended formulations against enveloped viruses including Zika, Ebola and emerging Coronaviruses. The Journal of infectious diseases. https://academic.oup.com/jid/article/215/6/902/2965582
5. Pickering, A. J., Davis, J., Blum, A. G., Scalmanini, J., Oyier, B., Okoth, G., … & Ram, P. K. (2013). Access to waterless hand sanitizer improves student hand hygiene behavior in primary schools in Nairobi, Kenya. The American journal of tropical medicine and hygiene, 89(3), 411-418. https://www.ajtmh.org/content/journals/10.4269/ajtmh.13-0008
6. van Doremalen, N., Bushmaker, T., Morris, D. H., Holbrook, M. G., Gamble, A., Williamson, B. N., … & Lloyd-Smith, J. O. (2020). Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMc2004973?query=recirc_mostViewed_railB_article
8. Zhang, J., Wang, S., & Xue, Y. (2020). Fecal specimen diagnosis 2019 Novel Coronavirus–Infected Pneumonia. Journal of Medical Virology. https://onlinelibrary.wiley.com/doi/full/10.1002/jmv.25742
9. Kampf, G., Todt, D., Pfaender, S., & Steinmann, E. (2020). Persistence of coronaviruses on inanimate surfaces and its inactivation with biocidal agents. Journal of Hospital Infection. https://www.sciencedirect.com/science/article/pii/S0195670120300463
10. US Centers for Disease Control and Prevention, 2020. Water Transmission and COVID-19 Drinking Water, Recreational Water and Wastewater: What You Need to Know. Website, accessed March 25, 2020. https://www.cdc.gov/coronavirus/2019-ncov/php/water.html