Environmental contamination by SARS-CoV-2 in a designated hospital for coronavirus disease 2019

Abstract

Background: Coronavirus disease 2019 (COVID-19) is characterized by risk of nosocomial transmission; however, the extent of environmental contamination and its potential contribution of environmental contamination to SARS-CoV-2 transmission are poorly understood. This study aimed to investigate whether environmental contamination may play a role in SARS-CoV-2 transmission.

Methods: Air samples were collected by natural precipitation, and environmental surface samples were collected by conventional surface swabbing. SARS-CoV-2 RNA detection was performed using reverse transcription polymerase chain reaction.

Results: Viral RNA was not detected in the 44 air samples. The positive rates in 200 environmental surface samples in medical areas (24.83%) was higher than that in living quarters (3.64%), with a significant difference (P < .05). The positive rates were 25.00% and 37.50% for the general isolation ward and intensive care unit, respectively, and no significant difference was observed between them (P = .238). The top 5 sampling sites with a positive rate in medical areas were beepers (50.00%), water machine buttons (50.00%), elevator buttons (42.86%), computer mouses (40.00%), and telephones (40.00%).

Conclusions: Most of the touchable surfaces in the designated hospital for COVID-19 were heavily contaminated, suggesting that the environment is a potential medium of disease transmission. These results emphasize the need for strict environmental surface hygiene practices and enhanced hand hygiene to prevent the spread of the virus.

Keywords: Air; Disinfection; Environmental surface; Hand hygiene; Hospital-associated infection.

Fig 1

Room layout of the general isolation ward 1 and the living quarters showing environmental and air sampling sites. Numbered labels correspond to environmental sampling sites. ① beepers; ② bed rails; ③ desktops;④ bedside tables;⑤ oxygen cylinder valve;⑥ medical equipment such as ventilator, monitors, and X-ray devices, etc;⑦ door handles;⑧ elevator buttons;⑨ keyboards;⑩ computer mouses;⑪ telephones; ⑫ water machine buttons; A refers to air samples. The medical area with moderate and high risk contains patient's room, nurses station, buffer room for taking off PPE, and elevator; the living quarters with low risk contains the rest rooms, office area, and buffer room for taking on PPE.