Trachoma elimination and surveillance strategies

• To review the effectiveness and operationalisation of the trachoma surveillance strategy in Ghana
• To compare the different indicators (clinical, infection and antibody) for trachoma surveillance and their use in decision making to validate elimination
• To inform the understanding of the transmission of key infections through the sero-surveillance of multiple pathogens using the trachoma surveillance platform (single cross-sectional survey)

In order to achieve elimination of blinding trachoma, a country needs to demonstrate that the elimination prevalence thresholds have been surpassed and then sustained for a two-year period. Ghana achieved the thresholds in 2008, and since 2011 has been implementing its trachoma surveillance strategy, which includes community and school screening for signs of follicular trachoma, in each trachoma-endemic district.

In 2015 and 2016, a district-level, population-based survey was conducted to validate elimination of blinding trachoma. Decisions on elimination are currently made based on prevalence of clinical evaluation of ‘trachomatous trichiasis’ and ‘trachomatous inflammation – follicular’ (TF), the second of which has been shown to be a problematic indicator in low prevalence settings. Further evidence is required to determine the optimal surveillance strategy and indicators for trachoma.

Pre-validation surveillance surveys were conducted in all previously trachoma-endemic districts of Ghana but with the addition of eye swabbing to test for chlamydia trachomatis infection (using PCR) and finger pricking to collect bloodspots for antibody testing (using ELISA).

Surveillance for additional infections (including other NTDs and possible WASH-associated diseases) was also included by testing for antibodies to the various pathogens using the same sera collected for trachoma (using Luminex multiplex assays). Finally, document analysis and qualitative methodologies were employed to review the operationalisation of the trachoma surveillance system used in Ghana.

• Read the journal article: “Serological and PCR-based markers of ocular Chlamydia trachomatis transmission in northern Ghana after elimination of trachoma as a public health problem”
• Read the journal article: “Surveillance for peri-elimination trachoma recrudescence: Exploratory studies in Ghana”