1. Department of Gastroenterology, Hepatology and Infectious Diseases, Heinrich-Heine-University, Düsseldorf, Germany
2. Department of Medical Microbiology and Hospital Hygiene, Heinrich-Heine University, Düsseldorf, Germany
3. Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
4. Mahidol-Oxford Tropical Medicine Research Unit; Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand