1. Department of Microbiology, Princess Margaret Hospital for Children,1 and
2. Division of Virology, TVW Telethon Institute for Child Health Research,2 Subiaco, Western Australia 6008, Australia;
3. Institute of Health & Community Medicine, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia3; and
4. Department of Pathology, Singapore General Hospital, Singapore 1696084