Ethics approval and consent to participate
Ethical approval to conduct the study were obtained from Muhimbili University of Heath and Allied Sciences Senate Research and Publications Committee (Ref. No. 2015-10-27/AEC/Vol.X/54), National Health Research Ethics Committee (Ref. No. NIMRlHQ/R. SaJVol. 1X12144), Tanzania Medicines and Medical Devices Authority (Ref. No. TZ16CT007), and Regional Committee for Medical and Health Research Ethics of Western Norway (Ref. No. REK2015/540).Written informed consent was obtained from each study participant before the enrollment in the study.