1. Department of Microbiology, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, New Territories,1
2. Department of Microbiology, The University of Hong Kong, Queen Mary Hospital,2 and
3. Institute of Pathology, Sai Ying Pun Hospital, Sai Ying Pun,3 Hong Kong SAR, China, and
4. Department of Microbiology, Centre for Tropical Diseases, Cho Quan Hospital, Ho Chi Minh City, Vietnam4