Department of Prevention and Health Care;
Dongying Shengli Oilfield Central Hospital;
Dongying 257000;
Shandong;
China;
Department of Epidemiology;
School of Public Health;
Shandong University;
Jinan 250012;
Shandong;
China;
Tianjin Entry-Exit Inspection and Quarantine Bureau;
Tianjin 300000;
China;
Department of Nutrition and Food Safety;
Zhejiang Center for Disease Control and Prevention;
Hangzhou 310051;
Zhejiang;
China;