I did a research once, many years ago because i always had sinus problems during the sinus problem time of the year. In my research I found that wheat has been blamed for a lot of diseases and other health problems. White flour yes but even whole wheat. (and sugar also) The yeast in the wheat enhances candidas albanicas. I stopped eating wheat...to this day and walla, I don't even get sick any more (unless I drink the water in the Philippines) My point here is, Europions were and still are big wheat eaters. But gained a certain amount of immunity to a lot of the diseases and sicknesses over time. South and north Americans ate more vegetable products and a lot of meat so they really had no sickness. So therefore there was nothing that the Spanish soldiers could have caught from the natives there. Though the Spanish may not have the disease, they can still be carriers. Thats how they gave their diseases to the natives. Not to be off topic here but this is something I read years ago before I had a computer. I would have to dig in my books in the attic to find where I got this info from so please don't ask...this was probably 15 or more years ago I did this research. All I know is it made sense to me, I tried it and it worked for me so now it makes even more sense to me. Why else would the Spanish be able to spread sickness so eaily to people who lived such a healthy lifestyle?