Funding for this research was provided by:
The Commission of Scientific Research and Innovation, Ministry of Higher Education and Scientific Research, Sudan (SRIC/2017/RP761.)
Received: 23 April 2019
Accepted: 5 June 2019
First Online: 11 June 2019
Ethics approval and consent to participate
: The protocol of the present study was approved by the Ethics Committee of the Ministry of Health in Sudan. The sample collection was performed after written consents were obtained from all the participants.
: Not applicable.
: The authors declare that they have no competing interests.