How much dirt is OK?

Posted on 20 June 2016

As a parent, of course you want to keep your child away from germs and bacteria. But according to what’s known as the ‘hygiene hypothesis’, some exposure could
make kids stronger. 

Many parents wouldn’t dream of putting their baby’s dummy back into their mouth after it’s touched the floor without sanitising it first. And yet, a 2013 Swedish study has found that children of parents who did put fallen dummies back into their mouths with little more than a quick lick were less likely to develop eczema, an auto-immune disorder.

Dr Chris Diffenthal, a paediatrician at Mediclinic Bloemfontein, says as a general rule this practice shouldn’t cause any harm. He believes that the ‘hygiene hypothesis’ holds true.

This medical hypothesis argues that a lack of early childhood exposure to infectious agents, microorganisms and parasites suppresses the natural development of the immune system, increasing susceptibility to allergic diseases.

‘The more babies are exposed  to germs, the lower their risk of developing allergies in future, and that includes asthma and eczema,’ he adds.

Dr Jack Gilbert, co-author of the book Dirt Is Good, is also co-author of a 2016 study that looked at the immune profiles of Amish children growing up on small, single-family farms. They found the Amish, whose environments are ‘rich in microbes’ (microorganisms), had significantly low rates of asthma.

Drawing the line

Dr Diffenthal advises parents to be realistic about the kinds of bacteria they expose their kids to, especially during the winter months.

‘Some of these germs we know to have a grave mortality risk – and that’s why we vaccinate children,’ he says. ‘I am really pro flu vaccines. Remember, if you are exposed to a cold or flu and you’re not vaccinated against all these other germs, you open the airways for other invasive infections.’

He adds that vulnerable children – those suffering from chronic immunity problems, malnutrition and HIV, and children who get repeated infections from daycare – should get their flu vaccine in winter.

But if there’s a cold going around at school, don’t panic, he says – most viral infections can’t be avoided.

‘We can prevent most invasive infections and some parasitic infections, but we can’t prevent all of them,’ he concludes.