A virus is not living. it is a structure consising out of proteins and DNA/RNA that can use a host to replicate (multiply). Having said this it can stay active on surfaces, e.g. metal, paper, toilets, glass, etc. Coronavirus (in general, not SARS-CoV-2) is said to stay active up to 48 hrs. Under lab conditions corona virus have been found to stay active/infective up to 9 days...

actually, some reports have claimed that the virus can stay alive more than two days but it needs some appropriate and exceptional circumstances and temperature.

There's no reason to doubt NEJM's numbers. They're not special. A few hours half life on surfaces is normal for viruses.

Please have a look at the following links.

https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/pdf

https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v1.full.pdf

The following supplementary file of a study published on Lancet microbe can tell more accurate figures to you:

https://www.thelancet.com/cms/10.1016/S2666-5247(20)30003-3/attachment/34ed069e-7268-42ae-8627-df3aa869d81b/mmc1.pdf

Thanks for all reply. @Carsten, does it mean that the RNA of SARSCov-2 still can replicate after staying in the outer of droplets (dry) for days? The structure of corona and RNA is not degraded?

@John, In determination of viable virus, is the sample (swab) incubated/planted/infected in host or media or just chemical/physically counting/determining the RNA?

https://m.economictimes.com/magazines/panache/how-long-can-coronavirus-live-on-surfaces-or-in-the-air/amp_articleshow/74690737.cms

Depending on the material and the conditions, human coronaviruses can remain infectious from 2 hours to 9 days. At temperatures of around 4°C or 39.2 °F, certain versions of the coronavirus could remain viable for up to 28 days. At temperatures of 30–40°C (86–104°F), coronaviruses tended to persist for a shorter time.

Don't forget that the human droplets are composed of mucus, a glycoprotein complex that holds water, and prevents desiccation of the virus. Desiccation will denature the virus, but the rate limiting factor is the protective mucus within each droplet propelled from a human's mucous membranes. It is the mucus that allows the virus to survive more than a few minutes anywhere, except inside the host organism. Given the appropriate conditions, moderate temperature, humidity, etc., the mucus remains moist, and the virus viable. Not so without the mucus. Try this experiment yourself, it is easy to replicate. June 28, 2020 Gary Ordog, MD

Follow This Link Please:

https://www.webmd.com/lung/how-long-covid-19-lives-on-surfaces

SARS-CoV-2 can survive on human skin for up to 9 hours. Please see the link below.

https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1517/5917611