Pre-validation survey for the elimination of trachoma and evaluation of the effectiveness of the trachoma surveillance strategy in Ghana v2
Authors: Debrah Oscar , Ernest Mensah not provided , Laura Senyonjo not provided , Dziedzom K. de Souza not provided , Tei E. Hervie not provided , David Agyemang not provided , Didier Bakajika not provided , Benjamin Marfo not provided , Felix Ahorsu not provided , Seth Wanye not provided , Joseph Koroma not provided , Agatha Aboe not provided , Nana-Kwadwo Biritwum not provided 
Published: June 2017

Background: 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 three year period. Ghana achieved the thresholds in 2008, and since 2011 have been implementing their trachoma surveillance strategy, which includes community and school screening for signs of follicular trachoma and trichiasis, in each trachoma-endemic district. In 2015, the country plans to conduct a number of district level population based survey to verify elimination of blinding trachoma. This decision is 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. Objectives: This study will determine if Ghana has sustained the elimination prevalence thresholds. Additionally, the study will review the trachoma surveillance strategy employed in Ghana and if it was able to identify any potential resurgence of infection. It will also assess the relationships between the prevalence of the clinical sign TF, compared to prevalence of infection and antibody levels, after completion of what most observers believe to have been a successful programme. This will help to determine whether it may be appropriate to consider one or more alternative indicators for validating elimination of blinding trachoma. Surveillance for other infections (including yaws and other NTDs) will also be integrated into the pre-validation trachoma survey. Methods: The standard World Health Organization (WHO)-recommended population-based prevalence survey will be conducted in areas already scheduled to conduct validation surveys in 2015, but with the addition of eye swabbing to test for infection and finger pricking to collect bloodspots for antibody testing. Villages identified with a TF prevalence ≥5%, either retrospectively, during the on-going surveillance or during the district level survey (index village), will result in focal screening of children in neighbouring villages (and the ‘index’ village), including a clinical assessment and tests for trachoma infection and antibody levels. Surveillance for additional infections will also be included through antibody testing using the same sera collected for trachoma. Finally, document analysis and qualitative methodologies will be employed to review the operationalization of the trachoma surveillance system in Ghana. Impact: Results from this study will provide the Ghana Health Service with evidence, as to whether the country has sustained their elimination targets for trachoma. It will also inform the WHO-led Alliance for the Global Elimination of Trachoma by 2020 (GET2020) on the appropriateness of alternative indicators and surveillance methodologies for verification of blinding trachoma.