I read somewhere that the life span of an Ascaris worm is between 2 and 5 years. But the females also lay hundreds of thousands of eggs every day. You eliminate most of them, of course, but rarely all, as they are stuck to your insides nestled in the mucous nests they build. They make diverticuli pockets in your intestines, and seal them off, so the anti-parasitical herbs can't get to them. That is why you have to keep going back and deworming the hatchlings. The eggs won't hatch out until the mother worm is dead, because she puts off a hormone to keep them dormant. It is very important to follow up with another cleanse after killing off a big mother worm because there may be oogles of hatchlings waiting to take her place. If you wait too long, the hatchlings will have time to start mating and laying eggs, and your illness could increase exponentially, very quickly, especially if you are someone with a compromised immune system, like me.
I am not a doctor or a parasite scientist. This is just what I've learned in my struggle to to stay alive.