Authors: Martha Powell, Future Science Group
Facial cleanliness is a key part of the elimination strategy for trachoma; however, there has been controversy over the reliability of measuring a ‘clean face’, leading to facial cleanliness not being assessed in most of the surveys that evaluate the impact of trachoma programs. New research, published in PLoS Neglected Tropical Diseases, has reported on the reliability of evaluating facial cleanliness, suggesting that assessments can be reliably reproduced.
As a leading infectious cause of blindness, the public health strategy for trachoma elimination is based on the acronym SAFE (surgery for advanced disease, antibiotics to clear infection, facial cleanliness and environmental improvement), which includes a clean face as an integral measure despite controversy about how this can be measured.
In this study, led by Sheila West (John Hopkins University, MD, USA), the team trained seven staff in Tanzania how to assess children for the presence or absence of nasal and ocular discharge. The newly-trained team then independently evaluated 60 children, aged 1–7, at two time points approximately 50 minutes apart.
The variation between graders and between grading sessions was quantified using unweighted kappa statistics, revealing better reliability measures than had previously been reported in a similar study. The researchers demonstrated that both intra-observer and inter-observer agreement was substantial for the assessment of clean faces.
These findings suggest that the assessment of clean faces could be incorporated into trachoma surveys, which already measure environmental improvements, in affected regions.
In their study the researchers write: “As long as training is provided, the estimate of clean faces in children should be reliable, and reflect the effort of families to keep ocular and nasal discharge off the faces. We recommend conducting more inter-observer trials in various trachoma settings and that assessing clean faces be added to surveys to trachoma control, which already measure environmental improvements, in districts.”
Sources: West SK, Ansah D, Munoz B, Funga N, Mkocha H. The “F” in SAFE: Reliability of assessing clean faces for trachoma control in the field. PLoS NTDs. doi:10.1371/journal.pntd.0006019 (2017); www.eurekalert.org/pub_releases/2017-11/p-ja112217.php