Since March 14, more than 4 million Spaniards have been forced to celebrate their birthdays at home (alone or with whoever they are confined to). At most, they have been able to broadcast (and invite) their friends via video call.
This data of almost four million people comes from the application How many have their birthday? of the National Institute of Statistics (INE). The birthday day most affected by the confinement was March 19, with 122,875 celebrations .
Blowing out candles
By respecting social distancing, blowing out the candles does not constitute any particular risk. However, we may be sharing a home with people at risk, from whom we must maintain the greatest possible social distance .
This naturally implies not blowing out the candles (in the event that all the inmates later decide to eat the cake). The reason for this seems obvious: we are spitting on the cake .
But the risk becomes much more apparent when we consider a unique study titled Bacterial Transfer Associated with Blowout of Birthday Cake Candles , which found that blowing out cake candles increased bacterial coverage of this up to 1400% .
The author of this study, published in 2017, is Paul Dawson , a professor of food safety at Clemson University.
To keep things simple for the study, Dawson and his colleagues dispensed with an actual cake and placed a piece of aluminum foil on a Styrofoam base in the shape of a cake. His collaborators glued candles, lit them and blew them. They also ate pizza to pre-stimulate the salivary glands, to make it the closest thing to a royal party .
The team diluted the glaze with sterile water and spread it on agar plates for bacteria to grow. Each colony that ended up growing on the agar represented an original bacterial cell from the glaze .
On average, blowing out the candles increased the amount of bacteria in the frosting by 14 times. But in one case, it increased the number of bacteria by more than 120 times .
Fortunately, our mouths are full of bacteria, most of them harmless. So, unless we are with people with colds, as long as we are not squeamish, we should not take any action. In today’s pandemic circumstances, perhaps we should do so .