Also I think ICU who has done alot of research posted here often talks about the hyperinfection stage.. i.e, many people are walking around with parasites but only show symptoms when/if a hyperinfection stage is reached. I definitely think this is true for most. What causes proliferation appears very complex, hormones, immune system, nutritional status. I posted an article about hormones just now.. interesting reading. Cortisol appears to be a hormone that needs to be kept in check, i.e, keep stress levels down!