1. Pan African University of Life and Earth Sciences Institute (Including Health and Agriculture), University of Ibadan, Ibadan 200005, Nigeria
2. College of Medicine, University of Ibadan Teaching Hospital, Ibadan 200005, Nigeria
3. The Biotechnology Center, University of Yaoundé 1, Yaoundé P.O. Box 17673, Cameroon
4. Department of Public Health, Faculty of Health Sciences, University of Buea, Buea P.O. Box 63, Cameroon