LOS ANGELES — The novel coronavirus that causes COVID-19 can contaminate surfaces for several hours or several days depending on the material. But for how long? In addition to testing how the virus can also infect people via aerosols, researchers at UCLA discovered the length of time it can live on common household materials.
Scientists found that the coronavirus can live for up to three hours in aerosols, up to four hours on copper surfaces, up to 24 hours on cardboard, and as long as three days on plastic and stainless steel.
“This virus is quite transmissible through relatively casual contact, making this pathogen very hard to contain,” says co-author James Lloyd-Smith, a UCLA professor of ecology and evolutionary biology, in a media release. “If you’re touching items that someone else has recently handled, be aware they could be contaminated and wash your hands.”
The UCLA study mimicked the virus contaminating common household surfaces and common hospital materials via coughing or touching objects. The researchers investigated how long the coronavirus remained infectious on those surfaces.
Lloyd-Smith and his team had previously published a story in the journal eLife showing that screening travelers for COVID-19 isn’t effective. People infected with SARS-CoV-2, the official name for the virus, could be spreading it without knowing they have contracted it and before symptoms appear. Lloyd-Smith says that it is extremely difficult to detect the early stages of infection because of the virus’s unique biology and epidemiology. Most cases show no symptoms for at least five days after exposure.
“Many people won’t have developed symptoms yet,” he explains. “Based on our earlier analysis of flu pandemic data, many people may not choose to disclose if they do know.”
The study supports common guidance for avoiding exposure and stopping the spread of COVID-19, such as:
- Avoid close contact with people who are sick.
- Avoid touching your eyes, nose, and mouth.
- Stay home if you feel sick.
- Cover coughs or sneezes with a tissue, and dispose of the tissue in the trash.
- Clean and disinfect frequently touched objects and surfaces using a household cleaning spray or wipe.
The study is published in the New England Journal of Medicine.