Received: 24 August 2018
Accepted: 3 December 2019
First Online: 16 December 2019
Ethics approval and consent to participate
: This study was approved by the ethical committee of Amhara public health institute (reference number: APHI/01/742). Written informed consent from the study participants was also obtained before conducting this study.
: Not applicable.
: The authors declare that they have no competing interests.