A diagnostic instrument to help field graders evaluate active trachoma

ABSTRACT

The SAFE strategy (Surgery for trichiasis, mass treatment with Antibiotics to clear ocular Chlamydia trachomatis infection, and Facial cleanliness and Environmental improvement to reduce transmission) is being used to eliminate trachoma as a public health problem. Decisions on whether or not to implement the A, F, and E components of SAFE are made on the basis of the prevalence of trachomatous inflammation—follicular (TF) in 1–9-year-olds. TF has a precise definition: at least five follicles, each of which is at least 0.5-mm diameter, in the central part of the upper tarsal conjunctiva. Determining whether a follicle has a diameter ≥0.5mm is difficult using magnifying loupes alone. We have developed an ultra-low-cost solution: a follicle size guide that takes the form of a durable printed adhesive sticker which can be fixed to graders’ thumb nails for direct size comparison. This tool will be made available to health ministries free of charge. It is anticipated to simplify grader training, increase grader trainee pass rates, and prevent in-service diagnostic drift after training is complete.

KEYWORDS:

• Diagnosis
• epidemiology
• trachoma

Disclaimer

AWS is a staff member of the World Health Organization. The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions, or policies of the institutions with which they are affiliated.

Declaration of interest

The authors report no conflicts of interest.

Additional information

Funding

Production of prototypes and the final design was supported by The Fred Hollows Foundation.