The cumulative effect of viruses in day care

Tracy has a good question: “My 4 year old is not in day care – he stays with Granny. I heard that once you get a cold, you never get that cold again, and I am worried he isn’t exposed to enough germs now to keep him healthy later. Should we be trying to infect him with more colds now that he has the luxury of staying in PJs all day instead of hitting him with all these new viruses when he does start school?”

For many viral infections, it’s true: you get it once, you won’t get it again. Think about chicken pox, measles, or hepatitis A—suffer through the infection, or get the vaccine, and you’re pretty much protected for life. Second infections or breakthrough disease after vaccination can happen, but it’s uncommon. This doesn’t hold true for bacterial infections like pneumonia, whooping cough, or ear infections, but for many viruses immunity can last the rest of your life.

But the common cold isn’t caused by one virus, or even one family of viruses. Common cold symptoms occur with hundreds of kinds of rhinoviruses, coronaviruses, and the recently-discovered metapneumovirus, to name just a few. Each cold may earn you immunity from one variety of one virus, but there are plenty more of them lurking out there.

What about the cumulative effect of the dozens or hundreds of viruses on kids in day care? Do day care kids earn lasting protection from enough viruses to keep them healthier once they’re in school? And does that mean that kids who spent more time in their PJs with Granny will get sicker once they start kindergarten?

A study published in December 2010 tried to figure that out. Researchers followed about 1300 families in Canada over eight years to record the frequency of infections in children through their years of day care and school. They looked at upper respiratory infections, ear infections, and “tummy bugs” that caused vomiting and diarrhea. Their conclusion was actually quite satisfying: children, whether or not they attended day care, suffered through approximately the same number of infections over the course of the study. But day-care kids got more of their infections when they were younger, especially when they first started in group care, while kids who didn’t attend day care got more infections later when they started school. The piper gets paid, either way: get your infections over with early, or get them later.

It’s reassuring to know that overall, neither group of children was really sicker than the other. Whether or not children attend group care when they’re young doesn’t seem to affect the total number of infections, but rather only the timing of their infections. Parents can choose whether their children will get more infections now or later, but the total number of infections is going to be about the same either way.

Roy Benaroch is a pediatrician who blogs at The Pediatric Insider. He is also the author of Solving Health and Behavioral Problems from Birth through Preschool: A Parent’s Guide and A Guide to Getting the Best Health Care for Your Child.

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  • Youdeals

    Smaller kids are prone to virus more quickly as their immunity levels would be very low.Nannies should be well informed to practice hygeine and should know how the creche is maintaing its place.

  • SchoolBoardLady

    I’ve always thought this discussion of “kids getting sick in daycare” contained a lot of ‘assuage parent guilt with the assurance that there is a benefit to getting sick during daycare years”–an ADVANTAGE if you will, of kids in daycare over kids who stay home with mom.  Well, I breast fed my three kids and they attended preschool (3-5 hours per day–3-5 days per week, starting at age two.  And, they rarely got sick.  My oldest child who was breast fed the shortest amount of time (child two breast mile until he was two; child three nursed until she was three), was prone to strep infections which were completely eliminated once his tonsils were removed at age 5 (about the time my second child was born). From that point, my kids did not have one infection requiring an antibiotic and I can remember only one “cold” (running nose) –child number two.  Repeat, after oldest child had the tonsils out, NOT A SINGLE antibiotic was prescribed and NO colds or flu until high school!! I remember the year well, EVERYONE in our family got the flu in 2005, one dropped after the other–it just went through our family in serial, starting with the sophomore in high school, the oldest child. I think breast feeding is largely responsible for developing the immune system.
     They all had lice the spring of 2000–caught by the oldest child at school.

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