Coronavirus carriers can infect their environment with the pathogen even before showing symptoms, according to a new study from the Cleveland Clinic.

The findings are based on an analysis of several surfaces in the hotel rooms of two presymptomatic Chinese students who were quarantined before being diagnosed with the disease. This study highlights the role and importance of quarantine in preventing the spread of COVID-19, and why it’s essential that we stick to isolation measures even if we’re ‘feeling fine’.

Hiding in plain sight

“The detection of SARS-CoV-2 RNA in the surface samples of the sheet, duvet cover, and pillow cover highlights the importance of proper handling procedures when changing or laundering used linens of SARS-CoV-2 patients,” the authors explain.

“In summary, our study demonstrates that presymptomatic patients have high viral load shedding and can easily contaminate environments.”

The study looked at the hotel rooms of two students who returned to China from studying abroad on March 19 and March 20. They did not show any symptoms of viral infection initially, but were moved to the hotel for quarantine as a precautionary measure.

On the second day in quarantine, they both tested positive for COVID-19 — they were still asymptomatic at this time — and were hospitalized for monitoring and treatment.

Their rooms were closed off after they tested positive, and various surfaces throughout were sampled about three hours after the tests. The team took swabs from door handles, light switches, faucet handles, thermometers, television remotes, pillow covers, duvet covers, sheets, towels, bathroom door handles, toilet seats, and toilet flushing buttons, among other frequently-touched areas.

A total of 22 samples were collected from the two rooms. Eight of them tested positive for COVID-19. Six were from the same patient, identified as Patient A, and were harvested from the light switch, bathroom door handle, sheet, duvet cover, pillow cover, and towel. In Patient B’s room, positive samples were detected on a faucet and pillowcase.

The team notes that they saw larger viral loads after prolonged contact with sheets and pillow covers, suggesting that the pathogens found this environment particularly cozy. However, overall, the main take-away from this study is how carriers, even presymptomatic ones, can cause “extensive environmental contamination of SARS-CoV-2 RNA in a relatively short time.”

Such findings come to fill in the puzzle of how the coronavirus behaves in the environment. Previous studies have recorded its ability to survive on various surfaces, which varied between three hours and seven days, depending on the material. The present study comes to show how it can get there in the first place, and at which parts of its life cycle.

All in all, the coronavirus seems to easily spread to our environments, even before we know we have it. It’s also content to survive there for quite a long time, too, ready to hitch a ride on our hands towards our face. These two factors contribute to making it such a contagious virus, and they’re why the 14-day quarantine measures were instituted in the first place.

It’s also why such measures are still one of our most effective ways in curbing its spread.

The paper “Detection of Severe Acute Respiratory Syndrome Coronavirus 2 RNA on Surfaces in Quarantine Rooms” has been published in the journal Emerging Infectious Diseases.