San Diego, California - Researchers found virus on 60% of candies that had been handled by unwashed hands or deliberately coughed on.
The risk of catching Covid-19 on Halloween can be reduced somewhat with a simple candy-washing method, researchers reported on Thursday in mSystems, the site for the American Society of Microbiology.
In an accompanying press statement, they advise mixing three ounces (85 grams) of dish soap detergent containing Sodium laureth sulfate, or SLS (sometimes written as Sodium dodecyl sulfate, or SDS) per gallon (3.8 litres) of water, then submerging the candy so that all surfaces of the wrappers are covered.
After being submerged for at least a minute, the sweets should be rinsed with clean water.
To test this approach, they had 10 recently diagnosed Covid-19 patients handle typical individually-wrapped Halloween candy.
When the sweets were not washed afterwards, researchers found virus on 60 per cent of candies that had been handled by unwashed hands or deliberately coughed on.
Treating sweets with the dish-washing detergent reduced the amount of virus by 62 per cent, they found.
While cleaning Halloween candy "is reasonable if one wants to be extra cautious ... the main risk of Covid-19 transmission during trick-or-treating is airborne transmission," co-author Rodolfo Salido of University of California, San Diego said in a news release.