Amid reports that the United Nations has been grossly overestimating the scope of the global AIDS pandemic, a new book points to what may be an even greater miscalculation: AIDS relief efforts have failed to understand the crucial role of family and community networks in controlling the disease.

This is the message of Helen Epstein’s important new book, The Invisible Cure: Africa, the West and the Fight Against Aids. Her book is one long testimony to the necessity of at least some social structures operating on a human scale. Although Epstein doesn’t cite the principle of subsidiarity from Catholic social teaching, or the corresponding principle of sphere sovereignty from the Dutch Reformed tradition, the importance of intensely local communities as “first responders” is clearly highlighted. Her book shows that the few noteworthy successes in slowing the spread of AIDS and comforting the sick have not come from sophisticated international organizations, but from local communities.