1. Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
2. Virology Unit, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia
3. Herbitec (M) Sdn Bhd, 11-2 Jalan Sri Hartamas 7, Taman Sri Hartamas, 50480 Kuala Lumpur, Malaysia