A quick study of children’s toys and bacteria

FARGO -- When kids are covered in food, grime and other assorted sticky stuff, their toys and gadgets inevitably become covered in those substances, too.

FARGO -- When kids are covered in food, grime and other assorted sticky stuff, their toys and gadgets inevitably become covered in those substances, too.

To illustrate just how dirty kids’ toys can be, Birgit Pruess, North Dakota State University Department of Veterinary and Microbiological Sciences associate professor, tested various toys to see which harbored the most bacteria.

She tested plastic toys from a 1-year-old; a toy plane, figurine, stuffed animal, and video game from a 4-year-old; and a video game and cell phone from a 10-year-old.

It was not a real scientific study (it was not standardized, and the samplings were not precise enough, Pruess said), but it yielded some interesting results.

While preschoolers tend to leave a sticky trail wherever they go, older kids seem attached to their electronic devices, and babies put everything in their mouths. So whose toys carry the most germs?


It turns out the toddler’s plastic giraffe, which doubles as a teething toy, had the highest bacteria count of an estimated 450 colonies.

But the pre-teen’s cell phone, which she takes everywhere, came in second, with a bacteria count of roughly 150 to 200 colonies.

“Cell phones are dirty,” Pruess said. “We have them in our hands at all times. It’s probably the thing we touch the most.”

Surprisingly, the preschooler’s teddy bear, with which he sleeps every night, produced no bacterial colonies. Pruess snipped a bit of the bear’s fur for the experiment, and said it’s possible the bacteria was too strongly attached to the fibers. She expected the stuffed animal to have among the highest bacteria count.

The 4-year-old’s video game had a fairly high bacteria count of approximately 90 colonies, much higher than his other toys, which yielded between two and 18 colonies.  

Pruess tested a few of the toys for coliform (fecal) bacteria, but found none.  

Something to keep in mind, she said, is that bacteria are everywhere and most are not harmful.

“There are 10 times as many bacteria on our bodies as there are human cells,” she said. “They contribute to our health, and there’s a lot being done today to understand how they contribute to our health.”


People with good immune systems also naturally have good defenses against bugs, said Dr. Norbert Yoe, Essentia Health pediatrician.

And just because there are bacteria or germs on something, doesn’t mean that they’re all going to cause disease, said Dr. Brennan Forward, Sanford Health pediatrician.

“We’ve lived with bacteria and viruses for thousands of years and have adapted to being around them,” he said. “There is growing research that talks about how being too clean can potentially be not as advantageous.”

There’s a theory called the hygiene hypothesis, Forward said, which notes that more allergies are showing up in developed countries than in underdeveloped or developing countries. The reason might be reduced exposure to bacteria and viruses.

“If you think about it, it makes sense because our immune systems for thousands of years have had to deal with recognizing bacteria and viruses,” Forward said.

Our bodies develop a way to fight off the bad bacteria and viruses, and distinguish between the good and bad microbes, Forward added.

“If we over the past several decades have been more concerned with germs in general and trying to eliminate them and reduce the amount of exposure to them, we still have an immune system that wants to work. If it doesn’t have bacteria or viruses to keep itself efficient, it’s going to start looking for other things to react against, like normal things that are in our environment.”

How often parents should clean their kids’ toys depends on the situation, Yoe said. If it’s a favorite toy that’s used frequently, the child has been sick, or it’s been exposed to multiple people at a party or sleepover, Yoe said to clean it. Toys exposed to many environments, like balls that are taken outside and touched by multiple people, he said, should also be regularly cleaned.


“Every time you touch something, you leave some germs behind and you pick up some germs,” Yoe said.

But cleaning those toys doesn’t have to be difficult. Bleach or distilled vinegar can kill bacteria, but he said simple soap and water is one of the most effective ways of decreasing germ load and infection.

If toys look dirty, Forward said it’s a good idea to clean them. And toys children put in their mouths should be cleaned daily, he said.

If more than one child uses toys that are likely to go into their mouths, Forward said they should be sanitized daily using a cleaning solution labeled as a sanitizer. Parents should wait until the toy is dry before giving it back to a child, he said.

Making sure kids wash their hands after they use the bathroom and before and after meals also helps, Yoe said.

“When the germ load is less on their hands, there’s less transmission to their toys,” he said.

Plastic toys with smooth surfaces, he said, are the easiest to leave germs on, but they’re also usually easier to wipe down and a lot of hard plastic toys can be cleaned in the dishwasher.

Favorite stuffed animals, he said, probably have a pretty high germ load.


“Kids carry it around with them, and they use is as snot rag, but they don’t usually their share favorite toy,” he said. “Cloth toys don’t transmit as easily as plastic or smooth-surfaced toys, but they’re also harder to clean because the germs stick to them a little easier and they also pick up dust mites and allergens.”

Parents should check the toy’s label for recommended cleaning, but typically cloth toys can be cleaned in the washing machine, Yoe said. They can also be placed in a plastic bag in the freezer to kill off dust mites, he said.

Still, Forward said, it’s important to allow kids to get dirty.

“Let them play in the dirt, let them play in the sand, let them get dirty,” he said. “Overall, it’s beneficial for kids so we don’t have a lot kids growing up afraid of germs because they’ve been told germs are bad.”

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