The global epidemiology of childhood pneumonia 20 years on.

This section looks back on a ground-breaking contribution to public health, reproduces an extract of the original and adds a commentary on its significance from a modern perspective. To complement the theme of this month’s issue, Anthony Scott reviews a paper by BJ Selwyn that was published in 1990 in a supplement to Reviews of infectious diseases. Pages S870, S886 and S887 are reproduced with kind permission of Chicago University Press at: http://www.who.int/bulletin/volumes/86/6/08-052753/en/index.html