Environmental persistence refers to the length of time a pathogen, like SARS-CoV-2, is capable of surviving outside of the human body; the longer it survives, the more likely it is to cause an infection. The persistence of viruses can be affected by both the type of environment (e.g. surface, water, wastewater) as well as the physical and chemical properties of the environment (e.g. temperature, pH, humidity, sunlight exposure).

  • Faeces: SARS-CoV-1, a related coronavirus and the virus that cases Severe Acute Respiratory Syndrome (SARS), can survive for hours to days in faeces depending on the source (baby versus adult) and characteristics (diarrhoeal vs non-diarrhoeal) of the faeces (Study 1, Study 2). 
  • Surfaces: SARS-CoV-2 can survive for 2 hours to 9 days under laboratory conditions on different surfaces but is susceptible to surface disinfection. Please refer to the Surfaces section for more information.
  • Aerosols: SARS-Cov-2 can remain viable and infectious in aerosols for at least three hours and possibly up to 16 hours under laboratory conditions. 
  • Water: SARS-CoV-2 has not been detected in water sources and no data are currently available on the survival of SARS-CoV-2 in water although related viruses can survive in untreated water for days to weeks (Study 1, Study 2, Study 3). Conventional filtration and disinfection processes at water treatment facilities should effectively remove or inactivate SARS-CoV-2. This section will be updated as new evidence emerges. 
  • Wastewater: SARS-CoV-2 genetic material has been detected in untreated wastewater (Study 1, Study 2, Study 3, Study 4) but there are no reports of the detection or persistence of viable, infectious SARS-CoV-2 in wastewater. Similar viruses can remain infectious for days to weeks in untreated wastewater (Study 1, Study 2, Study 3). Conventional wastewater treatment processes should reduce risk posed by SARS-CoV-2 in wastewater.
  • Temperature: SARS-CoV-2 is sensitive to heat and will be quickly inactivated (killed) at high temperatures. For example, at temperatures of 70°C or higher, the virus will survive for five minutes or less. At 4°C, the virus is stable and is able to persist for weeks with little reduction in concentration.
  • pH: Many pathogens are sensitive to large fluctuations in pH (a measure of how acidic or basic an environment or substance is). One study has found that SARS-CoV-2 can survive in a wide range of pH values (pH 3-10).
  • Humidity: The coronaviruses that cause SARS and Middle East Respiratory Syndrome (MERS), as well as other coronaviruses, seem to survive longer at lower relative humidity though the effect of humidity on virus survival may also depend on temperature.
  • Sunlight exposure: SARS-CoV-2 may be less persistent in environments exposed to sunlight due to increased temperature (see above) as well as exposure to solar ultraviolet (UV) radiation. No data are currently available on the effectiveness of solar irradiation on inactivating SARS-CoV-2 specifically. 

Want to know more about faecal-oral transmission of COVID-19?

Editor's note

Author: Jackie Knee
Review: Tom Heath, Robert Dreibelbis, Oliver Cumming, Karin Gallandat, Kate Medlicott
Last update: 01.05.2020

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