- Correspondence to T Charles Witzel, Public Health and Policy, London School of Hygiene and Tropical Medicine, London WC1H 9SH, UK;
- Received July 19, 2018
- Revised December 11, 2018
- Accepted January 26, 2019
- First published March 4, 2019.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.