1. Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
2. Department of Medical Technology and Clinical Pathology, Mukdahan Hospital, Mukdahan, Thailand
3. Department of Medicine, Mukdahan Hospital, Mukdahan, Thailand
4. Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
5. Division of Pulmonary, Critical Care & Sleep Medicine, Harborview Medical Center, University of Washington, Seattle, Washington, USA
6. Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand