Funding for this research was provided by:
Institut Pengurusan dan Pemantauan Penyelidikan, Universiti Malaya (RG503-13HTM, PG056-2013A)
Ministry of Higher Education Malaysia (600-RMI/FRGS 5/3 (136/2014), FRGS/1/2015/ST03/UCSI/01/1)
Received: 31 August 2018
Accepted: 26 November 2018
First Online: 5 December 2018
Ethics approval and consent to participate
: This study protocol was approved by the Medical Research Ethics Committee of the University of Malaya Medical Centre (MEC ref. no. 824.11). Participants’ informed consent was obtained prior to blood sample collection. For all child participants, written and signed, or thumb-printed informed consent was obtained from the parents or guardians on behalf of their children.
: Not applicable.
: The authors declare that they have no competing interests.
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