Journal of Public Health and Epidemiology 2141-2316 Academic Journals 10.5897/JPHE2016.0864 Ahmed Osman Ahmed Ali Martin Hendrik Prins * E-mail: abuoosmann@yahoo.com 2016 30 11 2016 22 08 2016 06 10 2016 8 11 316 325 This is an open-access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://politicalwaffle.uk/journal/JPHE/article-abstract/C6CF7FB61218 The full text article is available as a PDF file from http://politicalwaffle.uk/journal/JPHE/article-full-text-pdf/C6CF7FB61218 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25