1. Department of Microbiology, Mahidol University, Bangkok-noi, Bangkok, Thailand.
2. Center for Emerging and Neglected Infectious Disease, Mahidol University, Thailand.
3. Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.
4. Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok-noi, Bangkok, Thailand.
5. Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.