1. Department of Biochemistry, Al Mafraq Hospital P O Box 2951, Abu Dhabi
2. Clinical Division, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
3. Department of Public Health Medicine, Faculty of Medicine and Health Sciences, UAE University, P O Box 17666, Al Ain, United Arab Emirates
4. Department of Medicine, Al Mafraq Hospital P O Box 2951, Abu Dhabi