Hello to all researchers. I wonder if we have reported cases of the presence of COVID-19 in treated effluents or drinking water?
If so, could they provide the location and analytical information and results? Because we can have more severe cases of dissemination exponentially if they occur.
It may seem a pedantic point, but the recent Dutch study, and many others, have found viral RNA from the novel coronavirus (SARS-CoV-2) in wastewater samples. This does not necessarily mean that the virus is still infectious.
With so much misinformation circulating on the internet and elsewhere, it is important that things are reported and discussed accurately.
I do not have links to the actual science but this article suggests that viable SARS-CoV-2 virus is found in feces. It would be very wise to take a sensible precautionary approach to avoid putting worker's, their families and the community at greater risk ...
Harry, I agree 100% that we should not be complacent. My concern, however, is that some sections of the media and ill-informed social networkers read these articles and draw the wrong conclusions. Yes, there is evidence of viable virus in faeces (and there was similar evidence during the SARS outbreak). However various people have (incorrectly) interpreted the recent Dutch study as proof of viable virus in wastewater. There may be a risk, and we should take precautions accordingly.
Jeremy. I agree with you 100%. People need to read such articles carefully before jumping to conclusions. For a reasonable assessment of the likely presence of viable COVID-19 in wastewater or its risk to drinking water supplies, there’s plenty of good published works on MERS and SARS, both of which are Coronaviruses.
COVID19 contamination in treated water indicates improper treatment to sewage/drinking water/ effluent.
In the traditional treatment processes, at the fag end, either chlorination or ozonation is envisaged to avoid any microbiological contamination.
This is done to ensure a certain excess of residual chlorine or ozone, then there is likelihood of further contamination, till it reaches the users.
The very fact that COVID19 was noticed in treated water, itself suggests that recontamination has happened & the same could not be prevented due to absence of residual chlorine/ozone.
Thus suffice it to say that under compliance of treatment standard alone has given rise to this observation.
In any case i suggest ozone treatment at the end of depuration processes. Ozone is very aggressive about virus. A lot of papers are in scientific letterature.
PCR will identify fragments of DNA and RNA but it does not indicate whether they are from viable microorganisms and whether they are infectious. So, disinfect properly and do not worry about residual fragments.
Here's a second link that actually refers to the same institute's research, but also mentions the official Dutch governmental support health institute RIVM which did similar tests and came to the same conclusion.
TO the right side of this web-page you can also follow a string of comments that still criticise the interpretation of the results (parts of RNA do not mean that the virus itself IS present in the water, but only WAS present somewhere upstream). For me irrelevant in case you want to determine where in the country the virus (re-)emerges, now or in the future.
The established KWR water-research institute n the Netherlands has tested for various COVID-19 RNA strings in raw municipal wastewater, with which they started before first reported patients occured in the Netherlands, and repeated couple of times. Not to see if the sewage water is contageous but to see if this set-up would be useful to determine per sewage plant how many of the people are infected...also as a predictive measure after the first peak (which we are experiencing now) has wavered off, in order to be pro-actively monitoring second/third etc. waves. THey did see a correlation, and propose to the state to instate this methodology.
The amount of patients in the hospital are not a good indication of how many people are actually infected (including the ones not showing any symptoms, but do excrete it with their faeces into the sewer), since only the severe cases of patients end up in hospital. Also the fact that by far not all people who are 'suspect' are being tested, let alone who carry the virus but do not know it...
KWR also tested the effluent of a conventional sewage plant located in the most heavily impacted area of the Netherlands (over-severe stress on the staff and IC rooms in the hospitals): no virus remains came out positive.
Here's the link (Dutch however....google translate?)
The Covid-19 virus has been found in wastewater f.i. at Schiphol airport. This means it was found on short distance from (and time after) it was released by a patient. Once in water the virus will not survive for longer than a few days. So the problem is eliminated without treatment of the wastewater. People in the wastewater utilities have to be careful en wear protection.
Not a resent one, though feces with coronavirus had been found in sewage (cannot find the reference, which I read some days ago). These are from some years ago for other strains:
Whilst the impact of the pandemic is clear and at times frightening, we need to remember that wastewater already contains many pathogens. They are indicators of the health of the population the treatment plant serves. If we are confident that wastewater treatment with final disinfection (UV or Cl2) is effective against known water borne bacterial and viral pathogens, then I don’t think Coronavirus is likely to pose a threat to plant operators, those taking reclaimed wastewater for re-use, or water sources from where water is extracted and treated to potable standards.