Text and Data Mining valid from 2018-09-04
First Online: 4 September 2018
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The University of the Witwatersrand’s Human Research Ethics Committee and the Institutional Review Board of the Johns Hopkins Bloomberg School of Public Health granted ethical approval for the study, including all consent procedures. This article does not contain any studies with animals performed by any of the authors.
: All participants provided written informed consent. The University of the Witwatersrand provided direction on participation by children (participants under the age of 18 years). For participants aged 16 and 17 years, both the child’s own consent and consent of a parent or guardian were required.