Covid-19 rarely spreads through surfaces. So why are we still deep cleaning?

‘Armed with a year’s worth of data about coronavirus cases, researchers say one fact is clear. It’s people, not surfaces, that should be the main cause for concern. Evidence from superspreading events, where numerous people are infected at once, usually in a crowded indoor space, clearly point to airborne transmission, says Marr. “You have to make up some really convoluted scenarios in order to explain superspreading events with contaminated surfaces,” she says.

‘Hand washing is crucial, says Marr, because surface transmission can’t be ruled out. But it’s more important to improve ventilation systems or to install air purifiers than to sterilize surfaces, she says. “If we’ve already paid attention to the air and we have some extra time and resources, then yes, wiping down those high-touch surfaces could be helpful,” she says.

‘Households can also ease up, says Pickering. Quarantining groceries or disinfecting every surface is going too far. “That’s a lot of work and it also is probably not reducing your exposure that much,” she says. Instead, reasonable hand hygiene, as well as wearing a mask and social distancing to reduce exposure from close contacts is a better place to focus efforts.’

Read here (Nature, Jan 29, 2021)

Could a cheap iodine mouthwash really help to beat Covid?

‘We all probably have a sense-memory of iodine: the blood-like drop to purify a camping can of stream-water or the inky dab with which your grandmother stained your grazed knee. It feels like an old-fashioned, primitive home remedy, yet could it also be an intriguing new weapon against our most modern threat: coronavirus?

‘One of the world’s leading authorities on infection in the mouth and nose believes the answer is yes. Stephen Challacombe is a professor of oral medicine at King’s College London, with a specialism in the immunology of the mucous membranes. His decades of experience meant that when the pandemic hit, his mind went immediately to one — literal — solution. Iodine mouthwash. “Yes. I have no doubt that this should be used,” Challacombe says, “and had it been, it would have saved lives.”

‘Bottles of this form of iodine, called povidone-iodine, also known by the most common brand Betadine, used to be on sale in British chemists, before the public began to favour fluoride rinses. It is still popular as a sore-throat gargle in many European countries, America, Australia and Far East countries such as Japan. When the pandemic struck, Challacombe and his colleagues wrote to the British Dental Journal reminding the scientific world of its potential.’

Read here (King's College Journal, Nov 9, 2020)

Antimicrobial surface coating kills coronavirus for 90 days: US study

‘A specially formulated antimicrobial coating can keep surfaces clear of a human coronavirus for up to 90 days with just one application, a preliminary study said Friday (May 15), suggesting a new line of defence against Covid-19.

‘The paper by researchers at the University of Arizona (UA), which has not yet been peer-reviewed, found that the amount of virus on coated surfaces reduced by 90 per cent in 10 minutes and by 99.9 per cent in two hours.’

Read here (Straits Times, May 16, 2020)