Last year in April, following a COVID-19 outbreak among hospital staff, an interdisciplinary team started investigating if there was virus contamination in the frequently used surfaces of hospitals/ medical facilities such as ICU and staff meeting areas.
New Research: A new study done by UC (University of California) researchers confirms there is low likelihood of SARS-CoV-2 contamination on hospital surfaces is infectious. The study was published on June 24 in PLOS ONE and conducted at UC Davis Medical Center. Angela Haczku, a respiratory immunologist and senior author on the study said that our team was the first to identify that SARS-CoV-2 virus sequences could be understood from environmental swabs collected from hospital surfaces.
Last year in April, following a COVID-19 outbreak among hospital staff, an interdisciplinary team started investigating if there was virus contamination in the frequently used surfaces of hospitals/ medical facilities such as ICU and staff meeting areas at UC Davis Medical Center. At that time the role of surfaces spreading the virus drew attention of many people including the researchers and scientists. They started collecting multiple samples during the first (April 2020) and the second (August 2020) waves of COVID from surfaces and also from the HVAC filters in the hospital. The researchers analysed the swabs taken from the surfaces for SARS-CoV-2 RNA to check infectivity. It also assessed the suitability of the RNA for sequencing.
Despite a significant increase in COVID-19 cases among hospital patients during the second wave, the team discovered that only 2 per cent of the swabs collected tested positive in August. Whereas 11 per cent of the swabs tested positive during the first wave in April same year.
Improved ICU patient management and strictly following cleaning protocols inside the hospital has helped in significantly reducing the virus contamination, said Haczku, professor of medicine, director at the UC Davis Lung Center.
Lessons from genome sequencing
The study showed that by genome sequencing, SARS-CoV-2 could even be detected from samples that otherwise were undetectable by using other common methods of testing such as PCR tests. The result also demonstrated that SARS-CoV-2 RNA even after collecting from a surface was not infectious. The study supports the hypothesis that contaminated surfaces may not be a major reason of spreading COVID-19 disease.
According to David Coil, project scientist and first author, at the UC Davis Genome Center, genome sequencing done on the hospital surface by collecting swab samples was very important. With the help of accurate viral genomic sequences, the researchers could understand infection behavior– how an infection moves.
The study was funded by a UC Davis CRAFT Award and The Chester Robbins Endowment.