Singapore— The 53-year-old cleaner working at stay-home notice facilities identified as the likely source of the Covid-19 community cluster at Westgate and Jem malls in Jurong East might have touched a contaminated surface. That’s how she might have been infected with the virus, says Dr Paul Ananth Tambyah.
Infectious disease expert Dr Tambyah, who is also the Singapore Democratic Party chairman, is quoted as saying this in an article in The Straits Times.
According to Dr Tambyah, the cleaner was not likely to have had direct contact with the people serving stay-home notices where she worked.
So, she could have been infected by either airborne or surface transmission of the virus.
Transmissions via respiratory droplets are considered the most common source of Covid-19 infections, hence the need to wear a mask over one’s nose and mouth.
However, recent studies have made the case for airborne transmissions as well, as evidenced by a recent article in British medical journal The Lancet, as well as announcements from the World Health Organisation and the United States’ Centres for Disease Control and Prevention.
Dr Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection, explained that the cleaner could have been infected either way, but is inclined to believe it was a case of surface transmission.
“Those in the first camp would assume that the infected person could have been coughing and the virus was carried through the air and the poor cleaner ended up breathing it in, even though she was wearing a surgical mask. The assumption is that the mask, if worn properly, still failed to block out very small virus particles,” Dr Tambyah is quoted by ST as saying.
But he pointed out that, as part of their job, cleaners do come into contact with very dirty surfaces, including toilets, which could have been the source of transmission.
However, he admitted that how Covid-19 is transmitted is still a subject of debate.”The mode of transmission is something which we have been debating for one year and we still haven’t come to a conclusive answer.”
Dr Alex Cook, vice-dean of research at the NUS Saw Swee Hock School of Public Health, is also quoted in the article as saying that lapses in personal hygiene occur and could have led to the infection.
“It is quite impossible for rules to be adhered to strictly 100 per cent. The index case could have taken off her mask to rub her nose after touching a surface and that could have resulted in her getting infected,” he said.
/TISG
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