John S Schieffelin1, Tan Xu2, Wenjie Sun3. 1. Department of Pediatrics, Section Adult and Pediatric Infectious Disease, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA. 2. Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2100, New Orleans, Louisiana 70112, USA. 3. Department of Global Environmental Health Sciences, Tulane University School of Public Health and Tropical Medicine, 1440 Canal Street, Suite 2100, New Orleans, Louisiana 70112, USA.