SARS-CoV-2 is found in faecal matter

Summary notes of the International Water Association (IWA) Webinar: “COVID-19: A Water Professional’s Perspective”

Date: 8 April 2020 Author: Maronel Steyn (member of IWA)

Panelists

• Joan B. Rose, Homer Nowlin Chair in Water Research, Depts of Fisheries & Wildlife and Plant, Soil and Microbiological Science, Michigan State University and Chairperson: IWA COVID-19 Task Force
• Charles (Chuck) Haas, Department Head, LD Betz Professor of Environmental Engineering, Civil, Architectural, and Environmental Engineering, Drexel University
• Rosina Girones, Professor of Microbiology of the University of Barcelona and Dean of the Faculty of Biology
• Gertjan Medema, Principal Biologist, KWR, The Netherlands

Does the corona virus (SARS-CoV-2) pose a particular risk to Water and Wastewater Treatment Plant Workers in terms of their risk of contracting COVID-19:

The panel concluded that no information is available that indicates a particular risk from COVID-19 to operators of waste water treatment works (WWTW). Wastewater does not pose additional risk to WWTW employees, but the importance of wearing the necessary personal protective equipment (PPE) was noted. The panel was of the opinion that SARS-CoV-2 should pose a similar risk to WWTW operators as all the other viruses that are usually in wastewater. They also mentioned that there was no additional risk or epidemiological evidence suggesting more infections noted amongst those workers to date. They concluded that there was not a particular risk to WWTW operators from SARS-CoV-2 based on epidemiological studies and other viruses.

Specific hot spots of concern at WWTW for occupational health risks:

The panel mentioned sewer sheds and headworks at WWTWs as places of particular concern for occupational health risks and mentioned that the correct PPE should be worn by staff (maybe mention what the correct PPE is). The panel further mentioned that bar screens and wet wells, and places where aerosols can be produced could be a potential source of SARS-CoV-2 and people need to be protected.

Medical waste / wastewater handling from COVID-19 facilities other than hospitals:

The panel expressed a concern for how waste and specifically wastewater (medical) would be handled by places (e.g., hostels, hotels) that are used to serve as interim COVID-19 quarantine or testing facilities or accommodation. These are places other than hospitals that are used in the interim for such purposes and do not usually handle medical wastewater. Such facilities should be watched carefully.

What do we know about the aerosilisation of viruses in general, their persistence in air and travel distances?

The lower the temperature, the more stable viruses will be. Other viruses were much more abundant in wastewater than the SARS-CoV-2 virus. Monitoring COVID-19 in wastewater effluent, methodology, value of this as indicator, findings to date: KWR has done excellent work on this to date and more information is available here: https://www.kwrwater.nl/en/actueel/what-can-we-learn-about-the-corona-virus-through-waste-water-research/ The panel member involved in this work mentioned that they used molecular methods. SARS-CoV-2is a RNA virus and that KWR did not look only at fragments as the virus will be unstable especially in sewage. They tested intact virus samples, purified the samples, extracted RNA and looked for specific gene fragments of SARS-CoV-2. They tested the fragments for 4 specific targets. The same method used in clinical setting – so their testing was aligned with clinical methodology. This method can however have a 100 – 1000 fold more fragments than the traditional culture methods (important to know this). They started testing before any infections were reported in the Netherlands and repeated it 6 days after the first case and again 2 weeks after many cases were reported. After the first infections were noted, they found clear signals of SARS-CoV-2 in the influent and after two weeks with many infections they found clear samples with all 4 targets in the influent. All effluent was negative to date (which showed them that the wastewater treatment works effectively removed SARS-CoV-2). The wastewater treatment works tested in the KWR study are all activated sludge systems as this is common practice in the Netherlands. They think that the SARS-CoV-2 screening of sewage water can be used as a tool to measure the virus circulation in a population (e.g. a city or a smaller municipality). If we can further substantiate and validate our method, the water sector will have a tool that provides valuable additional information about the spread of the virus in the population.

Sludge and survival:

No work has been done on SARS-CoV-2, COVID-19, sludge and degradation, but degradation should be fast as viruses are unstable. Studies on other viruses similar to COVID-19 found that they could survive at 4°C and for up to 14 days in the environment.

COVID-19 and groundwater

The panel do not expect SARS-CoV-2 to be found in groundwater. They mentioned that the further one moves away from wastewater into rivers and streams, the least one is to expect to find SARS-CoV-2. They therefore do not expect to find SARS-CoV-2 in groundwater.

Concluding remarks of importance:

WASH (Water Sanitation and Hygiene) principles are even more important now. We should make use of the signals in our WWTW as early warnings to help with community or public health. More data is needed.

The panel warned that as people emerge from lock-down, special attention should be given to large commercial buildings or blocks that were not occupied during lock down. Where plumbing was not used, there is cause for concern for other health impacts associated with biofilms or growth of microbes in plumbing that was not used for an extended period of time (e.g., showers and cooling towers and risk of Legionellae). More information is needed.

The panel mentioned that people can access more information from the World Health Organisation site, specifically on the WASH principles. They also mentioned that IWA serves as a hub for information and created a COVID-19 task force. The panel was excited to see people collaborating and urged for even broader collaboration and sharing of knowledge, for people to act fast and for better preparedness next time.

While the panel thought the health risk for waterborne transmission of COVID-19 was very low, it is still important to underpin this with facts. So much more information and research is needed (e.g., the infectivity of COVID-19 and the specific methods to determine this was mentioned).