SARS-CoV-2 can be transmitted, even from asymptomatic individuals, in different ways, including droplets, aerosols and, to a lesser extent, fomites.
Now, Brazilian researchers have evaluated the use of these products in a toothbrush disinfection protocol, report in an article published online at The Journal of Infectious Diseases.
As highlighted by the authors in the text, published in a Letter to the Editor, individuals infected with SARS-CoV-2 have “high viral loads in saliva, nasopharynx and oropharynx”, which can occur even in asymptomatic people.
Considering that toothbrushes can act as reservoirs for microorganisms and favor the transmission of diseases such as COVID-19, the authors estimate that disinfecting the brushes would be important to control the transmission of the virus in shared spaces.
A recent study has shown that commercially available mouthwashes can inactivate SARS-CoV-2 in vitro. The results showed that antiseptic solutions containing ethanol and essential oils – exemplified by the brand Listerine Cool Mint, to name one – had satisfactory effects on reducing viral load.
However, there are still no specific studies evaluating the efficacy of different mouthwash solutions in disinfecting toothbrushes, nor randomized studies showing that the use of these solutions would, in clinical practice, have a protective role against the transmission of COVID-19.
Disinfection Protocol
As proposed by the authors after a review of the available data on the subject, the disinfection of toothbrushes must follow the following steps:
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Wash your hands with soap and water or disinfect them with 70% alcohol
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Disinfect the toothbrush handle surface with 70% alcohol for 1 minute
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Brush your teeth
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Wash the brush and re-disinfect the handle surface with 70% alcohol for 1 minute
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Leave the brush immersed in a solution with ethanol and essential oils for 20 minutes
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Store the brush individually after letting it dry
According to the authors, the steps of disinfecting the brush with 70% alcohol are important in brushing in collective environments, such as schools or workplaces, and do not need to be performed in the domestic environment, if it is not desired.
Another important observation made by the authors: the brushes used by individuals known to be positive for SARS-CoV-2 should be discarded immediately after use. O in vitro revised studies for the elaboration of the protocol showed that it was possible to observe a satisfactory reduction in viral load with only 30 seconds of exposure to the tested solution. However, it is important to consider that the toothbrush has retentive niches of microorganisms due to its design – hence the recommendation for longer immersion.
More studies needed
“Toothbrushes play an essential role in oral hygiene, but they can also act as reservoirs for microorganisms, favoring the transmission of diseases in healthy and sick individuals”, write the authors.
even though in vitro The effectiveness of the ethanol and essential oils solution – as well as alternative solutions such as iodine-povidone – has been demonstrated in more than one study; more research is still needed.
“[R]Standardized clinical trials are necessary to verify the efficacy of oral rinsing in preventing the spread of the virus, including evaluation of toothbrush disinfection ”, conclude the authors.
The authors have disclosed no relevant financial relationships.
J Infect Dis. Published online December 28, 2020. Full text
This article originally appeared in the Portuguese edition of Medscape.
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