1. Department of Nutrition and Food Hygiene, Harbin Medical University, Harbin 150081, China.
2. Department of Biomedical Sciences, Faculty of Sciences, University of Ngaoundéré, Ngaoundéré 454, Cameroon.
3. Department of Epidemiology Biostatistics and Disease Control, School of Public Health, University for Development Studies, Tamale TL 1883, Ghana.
4. Department of Microbiology, Harbin Medical University, Harbin 150081, China.
5. Department of Health Services Management, Harbin Medical University, Harbin 150081, China.