Researchers at the University of California, San Diego School of Medicine (United States) have analyzed how Covid persists on surfaces, especially in hospitals, in order to see if it could be contagious.
In their research, published this week in the scientific journal Microbiome, the researchers sampled the surfaces of patients’ rooms before, during and after their occupation, and repeatedly collected samples of skin, nose and stool. of Covid-19 patients and their healthcare workers over time. In total, they analyzed 972 hospital-related samples for traces of SARS-CoV-2 over two months.
Their conclusions: the virus, or at least its genetic signature, abounds. The team detected the virus on the ground next to the beds of COVID-19 patients (in 39% of the samples tested), on the ground outside patient rooms (29%), and on surfaces inside the rooms (16%). Detection of SARS-CoV-2 tended to be highest during the first five days after the onset of the patient’s symptoms.
The researchers, in any case, point out that just because they can detect the virus’s unique genetic signatures on a surface does not mean that the virus can infect people. ‘Since they started the study, it is well documented that SARS-CoV-2 spreads mainly through close human interactions, whereas surface transmission is probably very rare. In addition, none of the health workers who actively cared for the patients in the study tested positive for the virus, “they justify.
Viruses are not usually alone. Whether in people or on surfaces, they are part of complex communities known as microbiomes, which can include a variety of other viruses, bacteria, and additional microbes. When looking for the coronavirus, the team discovered something else: a specific type of bacteria of the genus ‘Rothia’ was found together with SARS-CoV-2 more often than the rest, regardless of the place of collection. In other words, the presence of ‘Rothia’ strongly predicted that they would also detect SARS-CoV-2 in the same sample.
«Why this relationship? Does the bacteria help the virus to survive, or vice versa? Or is it simply that these bacteria are associated with underlying medical conditions that put patients at higher risk for severe COVID-19 in the first place? This is an area for future research ”, reflect these scientists.
