The preliminary findings of a JAMA published study highlight the importance of strictly adhering to environmental and hand hygiene to mitigate the spread of COVID-19.
To conduct this study, researchers assessed three patients at the dedicated COVID-19 outbreak center in Singapore between January 24 and February 4. The patients were confined to airborne infection isolation rooms with vestibules and bathrooms, and researchers collected samples from 26 sites as well as personal protective equipment (PPE) from study physicians exiting the patient’s rooms.
They collected samples over a two-week period on the fifth day of each week. One patient’s room was sampled prior to routine cleaning while the other two patient’s rooms were sampled post-cleaning. Air sampling was done every two days on the rooms, anterooms, and outside the rooms. Subsequently, clinical data and timing of cleaning were collated and linked with sampling results.
Considerable Environmental Contamination Found
The results of the study showed significant environmental contamination by one COVID-19 patient with positive virus samples found on the toilet bowl and sink, suggesting that feces may transmit the virus. Encouragingly, the researchers observed that post-cleaning samples were all negative. Moreover, the air samples all returned negative despite the extent of environmental contamination.
However, swabs collected from the air exhaust outlets tested positive, indicating that airflow may dislodge COVID-19 droplets and deposit them on equipment such as vents. The anteroom and cleaned corridor samples also came back negative, which suggests COVID-19 transmission risk via contaminated footwork is likely low.
“Significant environmental contamination by patients with SARS-CoV-2 through respiratory droplets and fecal shedding suggests the environment as a potential medium of transmission and supports the need for strict adherence to environmental and hand hygiene,” the researcher authors wrote of the findings.
The study had several limitations, including operational limitations as the result of the outbreak, and a small sample size. Also, the air volume sampled represented only a small amount of the total volume, and air exchanges in the room would have diminished the presence of COVID-19 in the air. The researchers noted that, “Further studies are required to confirm these preliminary results.”
Significant environmental contamination by patients w SARS-CoV-2 through respiratory droplets & fecal shedding suggests the environment as a potential medium of transmission & supports the need for strict adherence to environmental &hand hygiene. #COVID19 https://t.co/4ZtWzPRIJ0 pic.twitter.com/MSngcgDVLy
— Antibiotic Steward Bassam Ghanem🆔🌟 (@ABsteward) March 4, 2020
Important study from Singapore shows significant environmental contamination by #COVID19 patients via respiratory droplets and fecal sheddinghttps://t.co/I0OwJq718z
Extensive contamination in bedrooms and bathrooms
All post-cleaning samples were negative pic.twitter.com/oRTo28XtTp
— Andy Biotech (@AndyBiotech) March 5, 2020