1. School of Nursing and Public Health, College of Health Sciences, Howard College Campus, University of KwaZulu-Natal, Durban, South Africa;
2. Faculty of Agriculture and Natural Resources, University of Namibia, Katima Mulilo Campus, Katima Mulilo, Namibia;
3. School of Life Sciences, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Durban, South Africa