While the coronavirus may be able to survive on beds, floors, and other surfaces near COVID patients, it’s unlikely to be passed on to someone else, a new study finds.
Researchers at the University of California San Diego School of Medicine wiped surfaces in the rooms of COVID patients before, during, and after their occupancy and found SARS-CoV-2 – the virus that caused COVID-19 – in about 13 percent of the samples .
None of the health care workers caring for patients in the study tested positive, despite frequent contact with these surfaces, suggesting that surface transfer is rare and that personal protective equipment (PPE) is working.
The result also showed a new link between the coronavirus and a type of microbe that could be linked to cardiovascular disease and severe COVID-19.
The coronavirus can survive on surfaces near hospital patients – but those surfaces are unlikely to infect anyone, a new study by UC San Diego shows. Pictured: a researcher wipes the floor looking for COVID samples
The study complements previous research showing that the coronavirus normally spreads through the air, not through touch. Pictured: a researcher holds up a card indicating the swab sites for the study
At the start of the pandemic, public health experts warned Americans to be careful with surface transmission if the virus is spread through particles found on doorknobs, desks, and other common items.
“Washing your hands” has become a common mantra. Hand sanitizer sold out. The New York subway is closed overnight for cleaning
However, experts have now learned that superficial transmission is a rare phenomenon for the coronavirus.
Instead, the virus usually spreads through the air – either through larger particles released when an infected person sneezes or coughs, or through smaller particles that can travel long distances.
The new study adds to the evidence that surface transmissions are rare and provides new insight into how the coronavirus shares space with bacteria.
For the study, published Tuesday in the journal Microbiome, researchers looked at what the coronavirus does on surfaces by wiping patients’ sick rooms.
The team collected nearly a thousand samples from 16 patients with confirmed COVID cases, 10 healthcare workers who cared for these patients, and hundreds of locations inside and outside of patients’ hospital rooms.
These 16 patients stayed in the hospital for up to three weeks and the researchers collected samples before, during, and after their hospital stay.
From those surfaces they sampled, the researchers found that 13 percent of the sites had enough coronavirus to be detected by a PCR test, which is considered the gold standard for testing.
Samples taken from the floor next to patients’ beds and right outside their rooms were most likely to contain the coronavirus – with prevalence rates of 39 percent and 29 percent, respectively.
For areas within the patient rooms (without floors) the prevalence was 16 percent. These surfaces included ventilation buttons, keyboards, and door handles.
The surface samples had much lower concentrations of the coronavirus than the samples actually taken from patients – with a classic nasal swab and stool exams.
These lower concentrations suggest that the coronavirus present on hospital room surfaces is less likely to infect someone than coronavirus particles sneezed from a patient.
Floor locations near patient beds were more likely to be COVID positive
In fact, the study did not find any coronavirus infections that occurred through surface transmission.
No health care worker tested positive throughout the study, despite taking care of COVID patients and collecting their samples. This suggests that personal protective equipment and safety training reduce the risk of transmission for medical personnel.
“It’s huge on so many levels,” said Dr. Daniel Sweeney, doctor of intensive care and infectious diseases at UC San Diego Health and senior author of the paper, in a statement.
“We need to know if our personal protective equipment, PPE, is adequate, and luckily we now know that things like masks, gloves, gowns and face shields really work. This pandemic was a global catastrophe, but it could have been worse if our healthcare workers got infected, especially if we didn’t know why.
In addition to the coronavirus itself, the researchers looked at microbes that interacted with the virus.
The Rothia microbe has often been found with the coronavirus, suggesting that the bacteria and virus may have formed some kind of partnership
Microbes live in the human body – many of them in our digestive system – as well as outside the body. They can have a huge impact on the body’s ability to fight disease.
The researchers examined the genetic makeup of all the microbes found in their coronavirus samples.
“Although it feels like we’ve lived with this virus for a long time, the study of the interactions between SARS-CoV-2 and other microbes is still new and we still have many questions,” said Dr. Sarah Allard, UC San Diego scientist and another lead author on the study.
“The more we know about how a virus interacts with its environment, the better we can understand how it is transmitted and how best to interrupt transmission to prevent and treat the disease.”
Notably, Allard and her team often found the virus along with a specific type of bacteria called Rothia. This bacterium was found more frequently in COVID-positive samples than in other non-COVID samples.
The Rothia Species are common in the human mouth, but can also invade the digestive system.
UC San Diego researchers found that this bacterium has been linked to cardiovascular disease. Patients who had cardiovascular disease prior to COVID-19 were also more likely to have had more Rothia in their rehearsals.
‘Why this relationship?’ asked Allard.
“Do the bacteria help the virus to survive or vice versa? Or are these bacteria only linked to the underlying medical conditions that put patients at higher risk for severe COVID-19 in the first place? This is an area for future research. ‘
While the results of this surface transfer study are not new, the microbes that have made friends with the coronavirus deserve further investigation. By studying these virus-microbe partnerships, researchers can develop more successful COVID treatments for future patients.