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. 2016 Sep 1;94(9):638–639. doi: 10.2471/BLT.16.020916

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(c) 2016 The authors; licensee World Health Organization.

This is an open access article distributed under the terms of the Creative Commons Attribution IGO License (http://creativecommons.org/licenses/by/3.0/igo/legalcode), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In any reproduction of this article there should not be any suggestion that WHO or this article endorse any specific organization or products. The use of the WHO logo is not permitted. This notice should be preserved along with the article's original URL.

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graphic file with name BLT.16.020916-Fa.jpg — Pigsty at a farm in the United Kingdom. Pigsties have nearly become a thing of the past with the growth of intensive farming methods.

Wellcome Images/Anthea Sieveking