Corneal pannus, Herbert’s pits and conjunctival inflammation in older children in Papua New Guinea

Abstract

Purpose: The prevalence of trachomatous inflammation—follicular (TF) in Papua New Guinea (PNG) suggests antibiotic mass drug administration (MDA) is needed to eliminate trachoma as a public health problem but the burden of trichiasis is low. As a result, WHO issued bespoke recommendations for the region. If ≥ 20% of 10–14-year-olds have both any conjunctival scarring (C1 or C2 or C3) and corneal pannus and/or Herbert’s pits, MDA should be continued. Equally, if ≥ 5% of that group have both moderate/severe conjunctival scarring (C2 or C3) and corneal pannus and/or Herbert’s pits, MDA should be continued. Methods: We identified 14 villages where > 20% of 1−9-year-olds had TF during baseline mapping undertaken 4 years and 1 month previously. Every child aged 10−14 years in those villages was eligible to be examined for clinical signs of corneal pannus, Herbert’s pits and conjunctival scarring. A grading system that built on existing WHO grading systems was used. Results: Of 1,293 resident children, 1,181 (91%) were examined. Of 1,178 with complete examination data, only one (0.08%) individual had concurrent scarring and limbal signs. Conclusions: The WHO-predefined criteria for continuation of MDA were not met. Ongoing behavioural and environmental improvement aspects of the SAFE strategy may contribute to integrated NTD control. Surveillance methods should be strengthened to enable PNG health authorities to identify future changes in disease prevalence.