Are children not getting sick as much as they should? Kids seem to be pretty good vectors for illness, as such it seems unreasonable that anyone would suggest that they are not getting sick enough. That being said the immune system is a constantly evolving response and it grows and changes with each infection. It makes sense that children who have not been around that long are lacking in immune response. The hygiene hypothesis goes one step further and blames an increase in Atopic diseases on children not developing their immune system enough.
The Hygiene Hypothesis is a proposal first suggested in 1989 by David Strachan. It suggests that the recent rise in atopic diseases such as allergies, asthma, and eczema could be related to a decrease in early childhood infection (Bloomfield et. al., 2006). There are quite a few issues with this hypothesis but recent data suggests that it is leaning in the correct direction. The first issue the hygiene hypothesis has is that it is extremely broad, suggesting that any and all infections help contribute in some way to protection from atopic diseases. Recent data suggests that exposure to specific microbes like Helminths could be a part of the cause. The evidence suggests a protective effect of heavy and chronic infections actually have a protective effect against atopy (Yazdanbakhsh et. al., 2004). Also their is a evidence pointing to a decrease in breastfeeding being another cause. Breast feeding allows for passage of antibodies from mother to child further developing the immune response (Rönmark et. al., 1999). A third piece points to an increase in antibiotic usage leading to overall increase in atopy (Foliaki et. al., n.d).
The second problem with the hypothesis is the use of the term hygiene hypothesis as it suggests that overall hygiene is somehow bad and we should adjust hygiene standards (Bloomfield et. al., 2006). This is not the case instead it is more important to determine the overall impact of all microbes on quality of life. Two of the above supporting pieces of evidence do not even deal with hygiene and instead deal with behavioral practices. Unfortunately their is no simple solution to this hypothesis as it has wide reaching connotations and more data is still being gathered both in support and against this hypothesis.
Bloomfield, S. F., Stanwell-Smith, R., Crevel, R. W., & Pickup, J. (2006). Too clean, or not too clean: the hygiene hypothesis and home hygiene. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 36(4), 402–425. https://doi.org/10.1111/j.1365-2222.2006.02463.x
Foliaki S, Nielsen SK, ISAAC Phase I Study Group
Antibiotic sales and the prevalence of symptoms of asthma, rhinitis,
and eczema: The International Study of Asthma and Allergies in Childhood
(ISAAC) Int J Epidemiol. 2004;33:558–63.
Rönmark E, Jönsson E, Platts-Mills T, Lundbäck B.
Different pattern of risk factors for atopic and non-atopic asthma
among children – report from the Obstructive Lung Disease in Northern
Sweden Study. Allergy. 1999;54:926–35.
Yazdanbakhsh M, Matricardi PM. Parasites and the hygiene hypothesis: regulating the immune system? Clin Rev Allergy Immunol. 2004;26:15–24.
Cool find here. I remember as a kid I would be playin in the dirt for hours and looking back on it I was exposed to many microbes. Yet now as an adult, I find myself not getting sick as often and I do attribute that to have that exposure as a child. Increasing demand for antibiotics and even generic allergy medications as of recent could point to atopy as the paper suggests and that might be due to increased concern for microbes. I personally think allowing yourself to get sick and get some exposure is generally a good thing to build up a tolerance later on--tread lightly though, don't go get some debilitating infection, that is not what I mean. But yeah allow your kids to get sick and don't over use the hand sanitizer you know--maybe not in these times but I think you get my point. I also don't really find hygiene hypothesis as a good term. A new way to put it would be to see how microbes affect daily life just as you said.
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