Ethics approval and consent to participate
Ethics approval was obtained from Amref Health Africa Ethics and Scientific Review Committee, the National Commission for Science Technology and Innovation, and Nairobi Metropolitan Services, Ministry of Health, Kenya. Verbal permission to conduct the study was obtained from five Kibera area chiefs, the local government administration covering the 10 villages. Informed consent was obtained from all participants, parents or caregivers, and assent from children age 12–17 years.