1 Department of Epidemiology and Public Health, Centre Pasteur of Cameroon, Yaounde, Cameroon; School of Public Health, Faculty of Medicine, University of Paris Saclay, Montigny-le-Bretonneux, France. Electronic address: bignarimjj@yahoo.fr.
2 Department of Internal Medicine, Douala General Hospital, Douala, Cameroon; National Public Health Laboratory, Yaounde, Cameroon.