1. Department of Medical Laboratory Science, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana; Botswana National Health Laboratory, Ministry of Health, Gaborone, Botswana
2. Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
3. Department of Pediatrics, McMaster University, Hamilton, ON, Canada
4. University of British Columbia, Vancouver, BC, Canada