A recent paper looks at how long coronaviruses can live on different types of surfaces. It is noted that the virus appears to live longer in colder, more humid environments. The writers are also wondering how we can kill coronaviruses.
The novel coronavirus, now officially known as COVID-19, has been making headlines since it first came to light in late 2019. COVID-19 has now infected 45,171 people from China to 23 other countries.
Because this version of coronavirus is new to science, researchers are struggling to understand how to treat infections and how to ensure that the virus does not spread further.
Prevention of Coronavoruses
Because there are no specific treatments for COVID-19, many experts focus on prevention.
Scientists at Greifswald University Hospital and Ruhr-Universität Bochum, both in Germany, have recently collected knowledge from 22 coronavirus studies.
Their research helps us understand how long coronaviruses live on the surface and how humans may be able to destroy them.
The authors initially compiled the information for inclusion in the forthcoming textbook; however, author Eike Steinmann explains that “under the circumstances, the best approach was to publish these verified scientific facts in advance in order to make all the information available at a glance.”
Their research, published in The Journal of Hospital Infection, focuses on coronaviruses responsible for two of the most recent outbreaks: severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
It also draws information from research that studied veterinary coronaviruses such as communicable gastroenteritis virus (TGEV), mouse hepatitis, and canine coronavirus.
How long will coronaviruses last?
The first part of the paper focuses on how long coronaviruses can live on inanimate objects, such as tables and door handles. The authors show that, depending on the material and conditions, human coronaviruses can remain infectious for 2 hours to 9 days.
At temperatures of around 4 ° C or 39.2oF, some forms of coronavirus may remain viable for up to 28 days. At temperatures of 30–40 ° C (86–104 ° F), coronaviruses tended to survive for a shorter period of time.
“Human coronaviruses may remain infectious on inanimate surfaces at room temperature for up to 9 days. The duration of persistence is shorter at a temperature of 30 ° C[ 86 ° F] or more. Veterinary coronaviruses have been shown to persist even longer for 28 d[ays].”
When scientists studied the literature on coronavirus persistence on different surfaces, the results were variable. For example, the MERS virus remained on a steel surface at 20 ° C (68 ° F) for 48 hours. However, TGEV survived for up to 28 days on a similar surface and at the same temperature.
Likewise, two experiments studied the survival of two SARS coronavirus strains on the paper sheet. Another lived for 4–5 days, the other for just 3 hours.
How to inactivate coronavirus
The authors discuss the best way to inactivate coronaviruses in the next section of their paper.
We conclude that chemicals, including hydrogen peroxide, ethanol and sodium hypochlorite (a bleach chemical), easily and effectively inactivate coronaviruses.
For example, the authors write that”[ [h]ydrogen peroxide was successful at a concentration of 0.5 per cent and an incubation time of 1 minute.” After evaluating the proof, the authors conclude:
“Surface disinfection with 0.1% sodium hypochlorite or 62–71% ethanol significantly reduces coronavirus infectivity on surfaces within 1 min[ute] exposure time.”
Conversely, solutions of a biocide called benzalkonium chloride obtained conflicting results; and chlorhexidine digluconate used by humans as a topical antiseptic was ineffective.
The authors write that”[t]ransmission in healthcare settings can be successfully prevented when appropriate measures are routinely taken.” Handwashing, in particular, is important.
We describe how, in Taiwan, “the construction of hand wash stations in the emergency department was the only measure of infection control that was substantially linked to the safety of health workers from[ SARS coronavirus].”
Although the studies outlined by the authors in this review did not investigate COVID-19, we conclude that the findings are also likely to be relevant to t All human coronaviruses examined by the study tend to be susceptible to the same chemical agents.