Studies in the pathogenesis and control of blinding trachoma. (360G-Wellcome-080741_Z_06_Z)

Trachoma is the leading infectious cause of blindness. Recurrent Chlamydia trachomatis conjunctival infection from childhood initiates a poorly understood inflammatory scarring response leading to blinding sequelae. Control measures focus on mass antibiotic treatment of chlamydial infection, but it is unknown if this will reduce future scarring and blindness, because conjunctival inflammation often persists after treatment.The aim is to identify the principal immunological and fibrogenic responses associated with progression in advanced trachoma, and to define biomarkers for progressive disease to assess interventions. This knowledge would support development of future control strategies such as anti-scarring treatments and an anti-chlamydial vaccine.Study Outlines:Case-control study of subjects at different stages of trachoma to characterise their conjunctival immune and fibrogenic gene expression responses by quantitative RT-PCR.Cohort study, following subjects with conjunctival scarring / trichiasis for two years for clinical evidence of progression; investigating associations between infectionand immuno-fibrogenic gene responses, to identify biomarkers for progression.Cohort study, lasting two years to identify immune and fibrogenic mechanisms associated with post-operative recurrent trichiasis, which might besuitable targets for anti-scarring treatment.Cohort study, to measure the effect of three rounds of annual mass antibiotic treatment on biomarkers for progressive scarring.