This is a harsh point to make. The sustenance of the middle-aged is arguably evident, but the role of medicine in poor countries — hindsight is 20/20, but what would be the most moral course of action in these environments? Non-intervention? I'd like to get examples on drug application with diseases the natives had learned to live with.

After this second turning point, the unwanted hygienic by-products of medicine began to affect entire populations rather than just individual men. In rich countries medicine began to sustain the middle-aged until they became decrepit and needed more doctors and increasingly complex medical tools. In poor countries, thanks to modern medicine, a larger percentage of children began to survive into adolescence and more women survived more pregnancies. Populations increased beyond the capacities of their environments and the restraints and efficiencies of their cultures to nurture them. Western doctors abused drugs for the treatment of diseases with which native populations had learned to live. As a result they bred new strains of disease with which modern treatment, natural immunity, and traditional culture could not cope.