In a recent study published in PLOS ONE, researchers conducted environmental surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ribonucleic acid (RNA).
SARS-CoV-2 spreads among humans through air, respiratory droplets, and contact with animals and contaminated surfaces. An animal study indicated fomites as a potential transmission route for SARS-CoV-2, wherein fomite exposure caused a milder clinical course than intranasal/aerosol exposure among animals. A mathematical modeling study concluded that surface disinfection and hand hygiene were critical measures for preventing coronavirus disease 2019 (COVID-19) via environmental transmission.
SARS-CoV-2 may persist for days on different surfaces, such as cardboard, plastics, copper, stainless steel, masks, and skin, depending on the relative humidity and temperature of the surfaces. Environmental monitoring of SARS-CoV-2 has been a pivotal aspect of public health surveillance. Nevertheless, COVID-19 environmental surveillance has been limited at large, congregated travel destinations.
The positivity rate of SARS-CoV-2 detection in samples from the PHF and select public places was 10.3%. More frequently, SARS-CoV-2 was detected on commonly touched surfaces, such as plastics, rubber, and stainless steel. All samples collected from the PHF floor surface, including the objects in contact with the floor (staff shoes), were positive for viral RNA.
Moreover, SARS-CoV-2 RNA was found in mop water containing detergent for cleaning. The highest concentration of viral RNA was detected in samples obtained from public and PHF restrooms. Notably, it could not be verified whether the virus was viable or infectious. Although the swab sampling technique successfully detected viral RNA, the collection efficiency was unknown.
Taken together, the study demonstrated the distribution and extent of SARS-CoV-2 contamination in public places and the PHF in Las Vegas. The high concentrations of viral RNA detected in public/PHF restrooms warrant frequent cleaning, hand washing policies, and implementation of hands-free controls limiting contact, such as automatic soap/water dispensers.