Building baby’s immunity or causing illness? How parents can spot the difference

In my experience, the five-second rule only seems to apply to second, third or fourth-born children.

Here’s how it goes:

A baby — practicing for future shot put stardom — launches a cracker into the air. It lands on the floor 10 feet away.

The parent picks it up, scans for cat hair and fecal matter, wipes it on their sleeve and hands it back.

This kind of relaxed reaction rarely happens with only children. If the first-born is the tosser, you can bet the cracker goes into the garbage. If it’s a toy or soother it will be washed, sterilized and hand-dried before returned.

All jokes aside, some parents wonder how to identify the line between building immunity and causing illness.

If a teething toy falls on the living room floor should you give it back without washing? What about toys at the indoor playground?

We went to microbiologist and the host of the Super Awesome Science Show Jason Tetro for answers.

Laurel Gregory: When something drops on the floor, walk me through what’s happening?

Jaston Tetro: So as soon as something drops on the floor, you are going to have microbes attach to it, no matter what. Now, granted if it happens to have just been cleaned, you’re going to have far less. But most of the time you’re going to have a few hundred, possibly a few thousand getting on to it. Unless you happen to be in a place where you know that there are pathogens, like say a kitchen, most likely there’s not going to be any harm to it. So you don’t have to worry what is on there… I think when it comes to the risk that a baby has, it’s really about the age. So in the first six months of the baby’s life, you really don’t want anything getting into baby except maybe breast milk and tender loving care. After six months, that’s when the immune system is starting to develop. So you are going to be introducing more, different types of bugs, besides they are going outside more often. When we get to around the age of two, the immune system is already in place so whatever ends up on the floor, it’s already going to be programmed as to what the immune system is going to do.

LG: What is the difference between a nice microbial introduction and ‘I would clean that off!’ ?

JT: It all comes down to where it is. If you know your environment you are going to know what type of bugs are there. So there are two places in the home that are going to have bugs we know are not so nice, and that’s the kitchen and the bathroom. So if something happens to drop on the floor in a kitchen or a bathroom, yeah, wash it off. It’s probably the best idea. But if it is the living room, bedroom, out in the backyard — unless it’s a dog park — I don’t think you are going to have any problems.

LG: So what’s in the kitchen and the bathroom? What’s lurking?

JT: From the kitchen, you are going to be seeing the food that’s coming in there — such as raw meats, vegetables, that type of thing — they may have microbes that could potentially cause you illness. So those will end up in droplets that could end up on the floor. So if you drop on the floor and end up with that 100,000 or so different microbes that can get on there, there’s a potential for something there that could make baby sick. As for the bathroom, I think it’s pretty self-explanatory! We go to the bathroom to remove germs from our bodies and those germs aren’t necessarily the best for baby.

LG: If I’m at an indoor playground and a soother falls on the floor, can I just pick it up and wipe it off? Is that a building immunity scenario?

JT: If you are in a playground where there are a bunch of children, the first thing you need to do is do an assessment.

Look around. Are there any sick kids? If there are you are probably going to want to clean it, because you have no idea where all that snot, saliva and other things are and it might get picked up and be transferred over to baby.

Tweet This Click to share quote on Twitter: Look around. Are there any sick kids? If there are you are probably going to want to clean it, because you have no idea where all that snot, saliva and other things are and it might get picked up and be transferred over to baby.

If everybody looks happy and they are not sick, then I don’t think that there is a problem because you are going to be doing those introductions. But again — make sure it’s after that six months of age.

READ MORE: How dangerous are the germs at your child’s playground and daycare?

LG: How is this building the immune system? What are the steps of that early exposure?

JT: So after six months of age, what’s going to happen is your body is producing cells that can be trained so that we develop an immune system that has memory. And it’s all about memory. Because if you experience something now, you want to be sure that you recognize it later on.

As you’re getting those exposures and they are not harmful, you are going to develop that memory in your body with you immune system.

Tweet This Click to share quote on Twitter: As you're getting those exposures and they are not harmful, you are going to develop that memory in your body with you immune system.

So from six months to two years, that’s really when the memory is churning up and developing — so that’s the best time to be getting that introduction.

LG: So let’s say if you are training for a marathon and you do a five kilometre run, you have muscle memory. Are the babies cells doing that? So, ‘I’ve been exposed to that before and I know how to fend it off?’

READ MORE: What’s in the water? The bacterial booby traps of summer

LG: Did I miss anything that you think is important?

JT: One thing you need to be sure of is: if you are picking something up that has fallen and it may have germs on it, just remember, your hands probably are also germy. So make sure your own hands are clean with sanitizer, before you pass over to baby. Unfortunately 80 per cent of infections are transferred by our hands. And the last thing you want to do is give them something like a safe pacifier, with unfortunately, dangerous hands.