COVID-19: Coronaviruses in water environments
COVID-19: Coronaviruses in water environments. Jefferson T, Heneghan C
Published on June 30, 2020
Transmission Dynamics of COVID-19
||La Rosa G, Bonadonna L, Lucentini L, Kenmoe S, Suffredini E. Coronavirus in water environments: Occurrence, persistence and concentration methods A scoping review. Water Res. 2020;179:115899. 2020
Coroviridae have been isolated in different types of liquids from waste to surface water but in general, they appear to be unstable. Chlorination and higher temperatures lead to their inactivation.
CoV persistence and survival in water environments was investigated by four studies looking at sewage and sludge, effluent from hospitals, tap water, pasteurised and unpasteurised water and urine.
SARS-CoV was detected in wastewater, domestic sewage, and tap water for 2 days at 20 °C and up to 14 days at 4 °C
Chlorine is a far more effective against CoV than other microorganisms because of its lytic action on the envelope
The occurrence and pathogenicity or potential pathogenicity of CoV to humans in water environments were assessed by five studies. Of note none of the samples for SARS-CoV 1 were viable but the presence of coronaviridae is widespread.
There was no evidence that human CoV is present in surface or groundwater or transmitted through contaminated drinking water.
The paper cites an update when it was going to press with reports of SARS-CoV-2 in municipal wastewaters in the Netherlands, Massachusetts, Australia (Link to Ahmed et al., 2020), France and Italy.
What did they do?
The study is a systematic review of what is known of the presence and survival of Coronaviridae in various water settings from the 12 included articles. Coronaviridae are enveloped viruses and are thought to survive differently than enteroviruses in water.
The small number of studies and the search date limit potential applicability to SARS-CoV-2 of the results. The review highlights how little we know of these emerging viridae.
The authors remark on the poor evidence base for enveloped viruses. The methods of concentration and collection for these viridae may not be appropriate.
|Clearly defined setting
||Demographic characteristics described
||Follow-up length was sufficient
||Transmission outcomes assessed
||Main biases are taken into consideration
What else should I consider?
This is an early review with a slim evidence base and no SARS-CoV-2 relevant data.
The occurrence of Coronavirus of interest for human health in water environments.
Persistence and survival of Coronavirus in water environments.
About the authors
Carl is Professor of EBM & Director of CEBM at the University of Oxford. He is also a GP and tweets @carlheneghan. He has an active interest in discovering the truth behind health research findings
Tom Jefferson, epidemiologist.