RQ1 - Reliability assessment: What is the intra- and inter-rater reliability of current qualitative F and novel quantitative hygiene metrics across study contexts?

RQ2 – Validity assessment: What is the validity of each metric of interest (i.e., quantitative hygiene and qualitative F metrics) with regard to recent personal hygiene practices and trachoma outcomes?

RQ3 – Utility assessment: What is the utility of each metric (i.e., qualitative and quantitative)?

RQ4 – Risk factor assessment: Do proxy facial and hand hygiene outcomes, as measured by the novel quantitative hygiene metric, represent risk factors of incident C. trachomatis infection?