1. Reno School of Medicine, University of Nevada, Reno, NV, USA
2. Department of Internal Medicine, McGovern Medical School, Houston, TX, USA
3. Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Center on Travelers’ Health, University of Zurich, Zurich, Switzerland
4. Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas School of Public Health, Houston TX, USA