You can find water purifiers at most hiking stores. The Platypus reservoir folds flat in yor pack and bends to get under the lower faucets. You need two water containers, one to pump from and another to carry the purified water. Not everyone needs to by a pump, four or so people can share one. Those using electrical appliances will need converters from 110v to 220v.
Most people do fine, perhaps moving kind of slow, but all right.
We will have available homeopathic and other natural medicines and there are native Andean herbs that can help. Most of our journeys adjust by starting low, and moving slowly over several days to the highest places thus very few people are bothered by the altitudes. Traveling the Andes means everywhere we go takes walking up and down. The elderly and infirm have been able to make it, however slowly. In the knowing of holistic happiness, physical strength can add much to mental and spiritual growth.