Declaration of interest
The authors report no conflicts of interest.
Beuy Joob
Sanitation 1 Medical Academic Center
Bangkok, Thailand
Viroj Wiwanitkit
Visiting Professor, Tropical Medicine Unit,
Hainan Medical University, China
Faculty of Medicine, University of Nis, Serbia
Joseph Ayobabalola University
Received 6 October 2015; accepted 22 November 2015