Evidences of SARS-CoV-2 virus air transmission indoors using several untouched surfaces: A pilot study

Abstract

Nowadays, there is an important controversy about coronavirus air transmission. The aim of this study was to determine aerosol transmission from patients with coronavirus infection using "COVID-19 traps" that included different untouched surfaces within them. 42 swab samples of 6 different surfaces placed in the rooms of 6 patients with a positive diagnostic of COVID-19 were analyzed with RT-PCR technique to evaluate the presence of the virus and its stability. Samples were collected at 24, 48 and 72 h. Patients were in an intensive care unit (ICU) and in a COVID-19 ward unit (CWU) at a Spanish referral hospital. None of the samples placed in the ICU unit were positive for COVID-19. However, two surfaces, placed in a CWU room with a patient that required the use of respiratory assistance were positive for coronavirus at 72 h. Surfaces could not be touched by patients or health workers, so viral spreading was unequivocally produced by air transmission. Thus, fomites should be considered as a possible mode of transmission of coronavirus and frequent disinfection of surfaces should be taken into account. Our results, although preliminary, point the importance of SARS-CoV-2 virus air transmission indoors and may shed some light in this debate.

Keywords: Aerosol transmission; COVID-19 traps; Coronavirus; RT-PCR; Untouched surfaces.

Graphical abstract

Fig. 1

Image of two “COVID-19 traps”. The left one is empty; whereas the right one has a surface inside that cannot be touched. This surface was later tested with nylon swabs moving them horizontally, vertically and transversely across all the sampling area. Immediately, the swab was immersed in viral transport medium and stored at −80 °C until analyzed.