BEIJING (REUTERS/XINHUA) - The coronavirus behaves much more like influenza than other closely related viruses, said scientists in China who studied nose and throat swabs from 18 patients, suggesting it may spread even more easily than previously believed.

In at least one case, the virus was present even though the patient had no symptoms, confirming concerns that asymptomatic patients could also spread the disease.

Although preliminary, the findings published on Wednesday (Feb 19) in The New England Journal of Medicine offer new evidence that Covid-19 is not like its closely related coronavirus cousins.

Unlike severe acute respiratory syndrome (Sars), which causes infections deep in the lower respiratory tract that can result in pneumonia, Covid-19 appears to inhabit both the upper and lower respiratory tracts.

That would make it capable of not only causing severe pneumonia, but also spreading easily like flu or the common cold.

Meanwhile, China’s health authorities also said that the coronavirus can be transmitted when someone is exposed to high concentrations of aerosol in a relatively closed environment for a long time.

Aerosol transmission was newly added in the latest edition of the diagnosis and treatment plan issued by the National Health Commission and National Administration of Traditional Chinese Medicine on Wednesday.

“The aerosol transmission happens conditionally,” Dr Wang Guiqiang, director of the infectious diseases department at Peking University First Hospital, said on Thursday.

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Singapore’s Ministry of Health (MOH) emphasised on Thursday that the publication recognised close contact and respiratory droplets are still the predominant mode of transmission for the virus.

MOH said the publication also contained three caveats for aerosol transmission: That it is possible with prolonged exposure, through high concentrations, and in a closed environment.

An example of such an environment would be an Intensive Care Unit (ICU).

“We have already taken that into account,” said the Ministry, adding that all healthcare workers in the ICU wear personal protective equipment.