How Many Germs Can a Sick Person Spread by Blowing Out Birthday Candles?

Blowing out candles on your birthday cake is a great American tradition, but is it really a good idea?

Blowing out candles on your birthday cake is a great American tradition, but is it really a good idea?

At Inside Edition, the office recently threw 25-year-old Elissa Bonito a party. Though it was hard to tell, Bonito was feeling a little under the weather, coughing, sneezing and blowing her nose all week. 

"Sometimes when you are sick, you don't look it, but you feel it," she said. 

Inside Edition decided to test whether blowing out the candles on her cake could leave germs that would be transferred to others when they eat the cake.

First, to get an idea of how germs can travel, Inside Edition correspondent Diane McInerney put a different cake under an ultraviolet light, then blew fluorescent powder over the delicacy. 

The difference between before and after was stark. The fluorescent powder showed how a single breath can blow germs onto a cake and lead to possible contamination. 

"I never really thought about germs going onto a cake when you are blowing out your candles, but I guess it makes sense," Bonito said. 

What about Bonito's birthday cake?

Inside Edition swabbed the cake for bacteria before and after Bonito blew out the candles, then sent the swabs off to a lab to see if Bonito's cold had infected the cake. 

Four weeks later, the results were in. Before the candles were blown out, the bacteria count on the cake was zero, according to the lab. Afterward? The amount of bacteria was so high the lab stopped counting after 5,000. 

What nasty germs made their way onto the dessert?

"Elissa, we found eight different types of bacteria," McInerney told Bonito. "One nasty one is called Staph aureus. It can cause skin infections and even pneumonia."

Bonito was stunned. 

So next time you have a birthday party, if you are feeling under the weather you may want to take a cue from Sen. Mitt Romney, who recently removed his candles one by one to blow them out. 

After all, you don't want to get others sick.