1. Discipline of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban 4001, South Africa
2. Public Health Department, Michael Chilufya Sata School of Medicine, Copperbelt University, Ndola P.O. BOX 71769, Zambia
3. Cancer & Infectious Diseases Epidemiology Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa