Researchers used the DNA of a virus that infects plants (and is harmless to humans) to understand how microbes spread in “isolated” hospital beds.
A study by University College London and Great Ormond Street Hospital, both in England, found evidence that viruses in hospital beds spread through the building within 10 hours and survive for about five days after initial contamination. The finding was shared on Monday (08) in the Journal of Hospital Infection.
To understand how Sars-CoV-2 DNA spreads in hospitals, the team artificially replicated some of the genetic material of a virus that infects plants (and cannot harm humans). Then, they mixed the particles with water in a concentration similar to that of the new coronavirus present in respiratory samples from patients with Covid-19.
After preparing the mixture, the researchers placed the water on a hospital bed rail in an isolation room – a place for high-risk patients. In the hours and days that followed, the team took and analyzed samples from 44 other surfaces scattered around the building.
They found that, after just 10 hours, the genetic material had already spread to 41% of the locations sampled on the hospital ward, from bed rails and door handles to armrests on waiting room seats, as well as toys and children’s books in the recreation area. This spread rate reached 59% of the sites analyzed in the three days after the first analysis, dropping to 41% on the fifth day.
“Our study shows the important role that surfaces play in the transmission of a virus and how critical it is to adhere to good hand hygiene and cleaning,” said Lena Ciric, one of the researchers, in a statement. “Our surrogate was inoculated once to a single site, and was spread through the touching of surfaces by staff, patients and visitors.”
The highest proportion of locations infected with viral DNA were in close proximity to the purposely contaminated hospital bed – on the third day of testing, 86% of the surfaces analyzed in the clinical areas tested positive. “A person with SARS-CoV-2, though, will shed the virus on more than one site, through coughing, sneezing and touching surfaces,” said Ciric.
The scientists also realized that, like Sars-CoV-2, the viral DNA analyzed was easily removed from the surfaces when the tested areas were properly cleaned. “Cleaning and handwashing represent our first line of defence against the virus and this study is a significant reminder that healthcare workers and all visitors to a clinical setting can help stop its spread through strict hand hygiene, cleaning of surfaces, and proper use of personal protective equipment (PPE),” said Elaine Cloutman-Green, co-author of the research.