Can We Use Antibodies to Chlamydia trachomatis as a Surveillance Tool for National Trachoma Control Programs? Results from a District Survey

Background: trachoma is targeted for elimination by 2020. world health organization advises districts to undertake surveillance when follicular trachoma (tf) <5% in children 1–9 years and mass antibiotic administration has ceased. there is a question if other tools could be used for surveillance as well. we report data from a test for antibodies to c. trachomatis antigen pgp3 as a possible tool. methodology: we randomly sampled 30 hamlets in kilosa district,tanzania,and randomly selected 50 children ages 1–9 per hamlet. the tarsal conjunctivae were graded for trachoma (tf),tested for c. trachomatis infection (aptima combo2 assay: hologic,san diego,ca),and a dried blood spot processed for antibodies to c. trachomatis pgp3 using a multiplex bead assay on a luminex 100 platform. principal findings: the prevalence of trachoma (tf) was 0.4%,well below the <5% indicator for re-starting a program. infection was also low,1.1%. of the 30 hamlets,22 had neither infection nor tf. antibody positivity overall was low,7.5% and increased with age from 5.2% in 1–3 year olds,to 9.3% in 7–9 year olds (p = 0.015). in 16 of the 30 hamlets,no children ages 1–3 years had antibodies to pgp3. conclusions: the antibody status of the 1–3 year olds indicates low cumulative exposure to infection during the surveillance period. four years post mda,there is no evidence for re-emergence of follicular trachoma. © 2016 winglee et al.