Received: 4 July 2019
Accepted: 13 August 2019
First Online: 22 August 2019
Ethics approval and consent to participate
: This study adhered to guiding ethical principles under the Declaration of Helsinki. Institutional access and permission to conduct the study at the schools was obtained from Ministry of Primary and Secondary Education (Ref C/426/3), Harare Province Education Director Office, and from the respective school headmasters of the three schools involved in the study. Ethical approval was sought and granted by the Human Research Ethics Committee (HREC) of the University of Cape Town (Ref: 016/2016) and, locally from Medical Research Council of Zimbabwe (Ref: MRCZ/A/2070) since the study was conducted in Zimbabwe. Participants provided written informed assent prior to participation following verbal explanations and reading of information letters explaining the study rationale and all procedural issues regarding the study. Parents provided written informed consent allowing their child to participate in the study.
: Not applicable as the manuscript does not contain any data from any individual person.
: The authors declare that they have no competing interests.