parasites can be good for us

Apparently before we got rid of gut worms in Europe we had virtually no allergies:

news.bbc.co.uk...

I've never had any alergies myself (AFAIK, fingers crossed, never had tests), but I know many people who have. I heard about hookworms a while back, although it's possible they could cause harm if 'normal' hookworms are used (they drink blood remember so it's possible they could pass on something the same way that mosquitos carry malaria) the price on treatment with sterile hookworms bred in labs is totally crazy and unafordable to anyone other than the rich.