Article History
Received: 31 October 2018
Accepted: 7 February 2019
First Online: 14 February 2019
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.
: All procedures performed in human studies were approved by the Human Research Ethics Committee of the University of Cape Town (HREC REF: 072/2014) and were performed in accordance with the ethical standards of the 1964 Helsinki Declaration and its later amendments.
: Informed consent was obtained from all individual participants included in the study.