Parasites, nutrition, child development, and public policy

Most public policy with respects to intestinal parasites is built on the premise that children would be better off without them. The evidence in the research literature for a casual link between parasitic infection and impaired cognitive function or delayed cognitive development is by no means complete. Review articles in the past few years have returned cautious verdicts regarding the beneficial effect of treatment: "not proven" but "plausible", or "a qualified yes". These views have raised a number of questions about the way in which research in this field has been conducted ad the conclusions that may legitimately be drawn from this body of work. This paper takes developmental view of the questions raised in the reviews, and outlines some of the implications for public policy.