Germ Exposure: Are we missing it?


Today’s posting is a bit short because…well, honestly, it’s because I’m grading papers. And because my daughter told me: “Mom, you should sleep more; I’d rather have a mom who doesn’t do all her work than one who is dead.” I took the point even thought I took it upon myself to explain to her that you have to sleep even less than I do to be at risk of dying from it.

But: by popular demand next week I’m going to try to walk through how you might think about grandparent visits and your babysitter/nanny. I’m sure it will make a lot of people mad!

Today, though: a couple of updates and then a discussion of germ exposure.


There’s new stuff on the website! Details on new testing breakthroughs, a discussion of how to safely process your take-out, and details on how COVID treatment works.

And, hopefully later today, we are planning to post something longer on kids and this pediatric inflammatory syndrome. Follow on Twitter for updates there. And please keep help us with getting the word out.

Pregnant? Join a Study!

UCSF is enrolling pregnant women in a new study. Recruitment blurb below!

There are limited data regarding risks of COVID in early pregnancy. The first trimester is a critical window of vulnerability when the fetal organ systems form and the placenta develops and establishes its communication between mother and baby. To help gather more data, a team of researchers at UCSF, and their nationwide partners, launched Assessing the Safety of Pregnancy In the CoRonavirus PandEmic (ASPIRE). This study plans to enroll 10,000 women between 4 and 10 weeks of pregnancy. They are collecting weekly blood spot COVID antibody tests, in the first trimester, symptom diaries, and then following these pregnancies through delivery and the baby’s first year and a half of life. You can learn more and enroll in the study at:

Germ Exposure: Are we Hurting Our Kids?

A slightly odd aspect of all of this is that despite the fact that we are in the middle of a viral pandemic, for many of us our kids have been much less sick in the last couple of months than usual. My kids are not seeing anyone else, so we have not had our usual complement of vomiting, fever, runny noses and the such. (We did have pinworms; apparently, they have a long incubation period. Also, they are SO GROSS. I digress.)

This is good in the sense that I think if I have to deal with vomiting it will push me over the edge, but a number of you have written to ask me whether this might be problematic. Is the lack of germ exposure hurting our kids?

There are a couple of sets of theory or data people are drawing on in developing this question. The first is what is called the hygiene hypothesis. This is the idea that exposure to dirt and microorganisms protects against allergic diseases through contributing to the immune system development. In practice, there is a lot of debate about whether this hypothesis is a myth or not.

But even if it is not a myth, this theory isn’t really about exposure to illness as much as exposure to dirt. And your kid can easily eat dirt alone. Trust me, I know. And our data on avoiding allergies — at least food allergies — increasingly suggests the value of early exposure to allergens (not to dirt) in avoiding them.

The other relevant piece of data here is on illness among young kids at day care versus home. I write about this some in Cribsheet. In discussing the choice between day care and home-based care (a nanny or parent) I note that kids who are in day care get sick more often (there is much data to support this; see one example here). However, they also seem to get sick less during elementary school. The higher illness burden at young ages seems to translate to less illness later.

In terms of relevance to our current situation, this evidence seems pertinent. If you have a toddler who would otherwise be in day care, they are likely “missing out” on some illnesses they would get and, yes, it is possible that this could translate to more illness later in childhood.

However, I think it would be a mistake to freak out about this. For one thing, although this feels like it has been and will be forever, it probably will not be. Kids will start to return to day care, if not in the next month then likely within the next year. It’s not avoidable. And even with the extra precautions, they’ll get some of the common colds they would have gotten anyway.

Second, the data which shows lower risk of illness in the elementary school years shows that illness rates equalize in middle school. So even if your child misses out on the toddler viruses, the elementary school viruses are coming. And to be completely honest, it is somewhat easier to deal with a sick eight year old than a sick 18 month old, mostly because they have a longer attention span for TV.

Weigh in!

Keep the thoughts coming. I cannot write back to everyone but I do read all of your emails, I promise.

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