Age-Specific Prevalence of Trachoma in Remote Australian Communities

PURPOSE: Trachoma is endemic in Australia, affecting remote Indigenous communities in northern, central and western Australia. The World Health Organization (WHO) defines a key requirement of elimination as a public health problem being the prevalence of active trachoma (characterised as trachomatis inflammation - follicular) below 5% in children aged 1-9 years. In Australia, screening is based in school settings and focuses on children aged 5-9 years. There is international evidence that active trachoma may be more common in children under five, meaning true Australian prevalence may be under-estimated. METHODS: In 2018, jurisdictions screened children aged 1-4 years in 64 at-risk communities in addition to usual screening of children aged 5-9 years. Active trachoma was assessed by trained graders according to WHO simplified grading criteria. Logistic regression using a mixed effect model was used to compare age groups. RESULTS: In total, 2907 children were screened for trachoma, with observed active trachoma prevalence 7.2% and 6.9% in children aged 5-9 years and 1-4 years, respectively. No evidence of association between age group and trachoma prevalence was found overall [OR = 1.29 (95% CI: 0.93-1.79)] and when analyses were restricted by geographic location or to communities meeting screening coverage thresholds. CONCLUSION: There was no evidence of higher active trachoma prevalence in children aged 1-4 years. These findings support the use of prevalence in children aged 5-9 years in assessing one of the key indicators of elimination of trachoma as a public health problem in the Australian context.