Effect Analysis of Different Environmental Disinfection Methods on Reducing Contamination of Surfaces of Omicron Ba.2.2 Variant of Sars-Cov-2 in the Fever Clinic in The Out- Broken of Shanghai

Abstract To investigate the effect of different environmental disinfection methods on reducing contamination of surfaces (CSS) of omicron BA.2.2 of Sars-Cov-2 in the fever clinic between March 20 to May 30, 2022 and analyze influence and related factors of the CSS. This study includes survey data from 389 positive patients (SPP) and 204 CSS in the fever clinic including the CSS type, the disinfection method; the duration time in the clinic, CT value, name, age, weight, mask type and gender of the SPP. Associations between study variables and specified outcomes were explored using uni-variate regression analyses. Among the 389 SPP, 22 SPP (CRP, 5.66%) caused CSS in the separate isolation room. 219 SPP (56.30%) were male. The mean age of SPP was 4.34±3.92 years old and the mean CT value was 12.44±5.11. In total, sampling times with exposure history were 9952, including 204 (2.05%) of CSS. Among the CSS, the positive rate of flat surface is the highest in either public area (2.52%) or separate isolation room (4.75%). Disinfection methods of Ultraviolet radiation + Chemical can significantly reduce the CSS in either public area (0% vs 4.56%) or separate isolation room (0.76% vs 2.64%) compared with the chemical alone (P＜0.05). Compared with ordinary SPP, the CRP is older (6.04y vs 4.23y) and the male proportion is higher (72.73% vs 55.31%). In particular, it is found that SPP contaminated their surroundings and therefore imposed risks for other people. Environment disinfection should be emphasized in Ultraviolet radiation + Chemical. The findings may be useful to guide infection control practice to omicron BA.2.2 of Sars-Cov-2.