I think it is true that many children are diaganosed with asthma and all along they had parasites. Not all, but it is a strong possibility.
Everything passes from mother to the unborn child.
I think another way of passing them is through the hands and nails unscrubbed. Most ppl do not srub under the nails and the eggs are present on hands and under nails.
Another way of contracting the parasites is through water and foods.