About the Authors
Yunnan Institute of Endemic Disease Control and Prevention, Dali City, Yunnan Province, People's Republic of China
Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
The authors have declared that no competing interests exist.
Conceived and designed the experiments: J-XY AG VC X-QD. Performed the experiments: J-XY X-QD C-HD Y-HZ. Analyzed the data: J-XY AG X-QD C-HD Y-HZ. Contributed reagents/materials/analysis tools: J-XY AG VC. Wrote the paper: J-XY AG VC.