1. Key Laboratory of Public Health Safety of Ministry of Education Department of Epidemiology School of Public Health Fudan University Shanghai China
2. Dehong Prefecture Center for Disease Control and Prevention Mangshi China
3. Dehong Prefecture People's Hospital Mangshi China
4. Mangshi City People's Hospital Mangshi China
5. Ruili People's Hospital Ruili China
6. Longchuan County People's Hospital Longchuan China
7. Yingjiang County People's Hospital Yingjiang China
8. Lianghe County People's Hospital Lianghe China