Contamination on mask and ward environment of SARS-CoV-2 infection re-positive persons

Abstract:

Objective To evaluate the contamination of SARS-CoV-2 on environmental object via SARS-CoV-2 nucleic acid re-positive persons, and provide data support for healthcare-associated infection prevention and control. Methods From June 15 to 30, 2022, 27 nucleic acid re-positive patients admitted to a COVID-19 designated hospital in Shanghai were selected. Basic information of patients were collected. Specimens were taken from the inside and outside of patients' masks wore on the sampling day and high frequently touched object surfaces in patients' ward. SARS-CoV-2 nucleic acid of specimens was tested. SPSS 20.0 was used for analysis. Results Of the 27 re-positive patients, 6 (22.22%) had a Ct value < 35 and 21 (77.78%) had a Ct value ≥ 35 in the first SARS-CoV-2 nucleic acid test after admission. Of the 162 environment-related specimens, 16 (9.88%) were positive for nucleic acid test, including 5 (3.09%) double-gene positive specimens and 11 (6.79%) single-gene positive specimens. Among the different sampling sites, positive rate of mattress+sheet was the highest (18.52%), Ct value of all positive environmental specimens was >35. Whether the Ct value of the first nucleic acid test of patients after admission was < 35 has nothing to do with the positive rate of nucleic acid test result of patient-related environment, difference was not statistically significant (P>0.05). Contamination of different object surfaces was not statistically significant (P>0.05). Conclusion Viral load of SARS-CoV-2 contamination on environment through respiratory tract of SARS-CoV-2 nucleic acid test re-positive patients is low, thus transmission risk through environmental media is low.