1. Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
2. Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
3. Department of Paediatrics, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
4. University Malaya Medical Centre, University Malaya Paediatric and Child Health Research Group, University of Malaya, Kuala Lumpur, Malaysia